Psychology of blindness

Compilation of
Alberto Rosa and Esperanza Ochaíta
Editorial Alliance

All rights reserved.

Alberto Rosa and Esperanza Ochaíta

Alianza Editorial, S. A. Madrid, 1993 .
Juan Ignacio Luca de Tena Street, 15, 28027 Madrid; phone: 7416600. ISBN: 84-206-
6539-8
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INDEX

Prologue, by Ángel Riviere... 5

Chapter 1. INTRODUCTION. CAN THERE BE TALK OF A PSYCHOLOGY OF THE

BLINDNESS?, by A. Rosa and E. Ochaíta... 8
1. Can we talk about a psychology of blindness?
2. Defectology or special educational needs?
3. Book plan and reader's guide

Chapter 2. CHARACTERIZATION OF BLINDNESS AND DEFICIENCIES

VISUALS, by A. Rosa... 24
Dimensions of visual impairments
2. Prevalence of visual impairments: some statistical data
3. Vision and the visual system
3.1. The visual system
3.2. Visual perception
4. Common diseases of the visual system and their functional repercussions.
5. Vision assessment
5.1. Who conducts the vision assessment?
5.2. The eye exam
5.3. The measure of vision
5.4. The visual report
5.5. Instruments for the assessment of visual perception
6. The use of visual remnants
6.1. The functional vision
6.2. Technical instruments for vision assistance

Chapter 3. PERCEPTION WITHOUT VISION, by F. Blanco and M. E. Rubio... 47

1. Somatosensory system
1.1. Anatomy and physiology of touch: the somatosensory system
1.2. The concept of tactile perception: theoretical problems
1.3. The perception of texture
1.4. The perception of complex patterns
1.5. The development of skin sensitivity .
1.6. The development of tactile discrimination ability
2. The vestibular system
3. The role of auditory perception
3.1. Anatomy and physiology of the auditory system
3.2. Sound discrimination
3.3. The localization of sound sources
3.4. The 'sense of the obstacle'
3.5. The role of hearing in the perceptual development of the blind
4. The external chemical senses
4.1. Taste
4.2. Smell
5. The experience of the world without vision

Chapter 4. BLINDNESS and PSYCHOLOGICAL DEVELOPMENT, by E. Ochaíta... 93

Early Childhood
 1.1. Sensorimotor intelligence
1.2. Motor development
1.3. Attachment and interaction
2. Representation, interaction, and symbolic function: communication, language, and
Game
2.1. The beginnings of representative capabilities
2.2. Imitation
2.3. Preverbal communication
2.4. Acquisition of spoken language
2.5. The game
3. The school stage
3.1. Intellectual Development
3.2. Social integration, schooling, and development
3.3. Discrepancy between figurative and verbal thinking
3.4. Learning and cognitive development.
4. Adolescence
4.1. Formal or abstract thinking
4.2. Blindness, touch, and language

Chapter 5. MOBILITY and SPATIAL KNOWLEDGE IN THE ABSENCE OF

VISION, by J. A. Huertas, E. Ochaíta and M. A. Espinosa... 177
Perceptual factors involved in displacement and knowledge
spatial
2. Movement and orientation in the environment
2.1. Mobility in the absence of Vision
2.2. Components of spatial orientation "
2.3. Instructional programs in orientation and mobility
2.4. Aids for orientation and mobility
3. The content of spatial representation in the blind
3.1. Organization of spatial representation
3.2. The elements of spatial representation
3.3. The spatial scheme and its functions
4. Development of spatial knowledge
4.1. Development of spatial knowledge in the preschool stage
4.2. Works based on Piagetian theory
4.3. Development of spatial representation or 'cognitive maps'
5. The different factors that determine spatial representation
5.1. Learning and development
5.2. The visual experience
5.3. The physical characteristics of the environment
6. Methods and techniques for outsourcing spatial knowledge
6.1. Global or cartographic procedures
6.2. Analytical procedures
6.3. Verbal descriptions
6.4. Relationships between the different methods
6.5. Spatial conduct
7. Some implications for the teaching of geography
Tactile maps
Chapter 6. READING IN THE VISUALLY IMPAIRED, by A. Rosa, J. A.
Huertas and C. Simón... 229
1. Access to cultural information. Reading processes and other substitutes
2. Reading systems for the blind
2.1. Brief Historical Overview
2.2. The braille system
3. The reading processes in the braille system
3.1. Reading activity and psychological processes
3.2. Movement of the hands in tactile reading of Braille
3.3. Perception and encoding in the tactile use of the braille system
3.4. The influence of context on the reading of the blind
3.5. The speed of braille tactile reading
4. Instruments and methods for the evaluation, teaching, and assistance in reading
the visually impaired
4.1. The teaching of Braille literacy
4.2. Reading Assessment
4.3. Technical aids for the reading of the blind and visually impaired
5. Summary and discussion: Are the processes of visual reading identical to those of
the touch?

Chapter 7. PSYCHOLOGY OF BLINDNESS AND GENERAL PSYCHOLOGY, by

A. Rosa, J. A. Huertas and F. Blanco... 280
1. Objectives of the chapter: metatheory and theory
2. What model of psychological subject do we manage? Towards the development of a
metatheoretical point of view
2.1. Methodological assumptions
2.2. A genetic perspective
2.3. Mediated action
2.4. Development as a sequential process. The Zone of Development
Next
2.5. Activity, communication, and motivation. The channeling of
Development
2.6. Remediation
3. Ascending to the concrete. The level of specific theories within the framework of
psychology of blindness
3.1. Perception and subjective experience
3.2. Knowledge representation
3.3. Representation of the environment and mobility
3.4. The tactile reading of braille
3.5. The development
4. As an epilogue: the integration

Bibliography... 320
PROLOGUE

It is usually asked of the prefaces of scientific books - and this is one - that they have the severity
and the neutral impersonality that science itself possesses. I appeal to the reader's indulgence.
(commonly referred to as "kind"), to allow me to break, for once, with that
habit that consists of situating oneself, from the beginning, far away, not here but there, in the
frosty regions of objectivity. I have two reasons to make that request: the subject
this book is too close to me. Its authors are also. My own subjectivity is
so committed to the topic that I would have to force the writing of this too much
prologue to make it objective. The question about what happens when one loses the
vision, of what the experience is like without seeing, constantly comes to my mind in the
In recent months: during this time, a person who is very dear to me has largely lost their vision.
nearby. The colors of her world have faded, the shapes have vanished,
have gradually become more faded, more subtle and imprecise. The loss of vision
is associated, in our intuition, with a kind of exile from that 'direct world', to
that our own vision gives us access to. At first, it is an experience
hard. It involves not only a "cognitive" reorganization but also the demand to relearn how to
to navigate the world, but also a genuine task of personal restructuring, and
overcoming the depressive reaction logic of the first months.
The person I am talking about, the one I am thinking of, has two main hobbies: writing and
paint. How is it possible to maintain those activities when you lose the
vision at an advanced age? One of the first things to discover, after that
the first brutal experience of loss, is that it is not only possible, without vision, to reach a high
degree of autonomy of movement or even carry out activities that seem so
visuals like writing... and even painting! This poem about the new experience, written
a few months after losing her vision, it is an impressive plea in favor of that
possibility and expresses with special sensitivity the moment when one begins to overcome
the first depression and to recover a different world,

XII Prologue

but no less rich in experiences than that of the seers. As the reader may imagine,
the poem is by the person I am referring to, María Angeles Gómez:

Now that the light has been denied to me and night has settled in my life, I must seek the
lamp lit at the bottom of the abandoned well. Living has not ended. It has
I have embarked on a new thrilling adventure. I am calm, standing, firm, and upright and
ready to face the unexpected. The rose will bloom in spring
and I will not enjoy its colors,
but the aroma will give me its charm. I will hear the true word.
and I will continue to love. And my loves will transform my into music.

Although I may not be the right person to make an 'objective' critique of the poem, I
It seems evident that the elements reflecting the presence coexist in it, even of the
depressive experiences, such as 'the night', 'the bottom of the abandoned well', the
"crying," with those others who, agonizingly confronted with them, express the
recruitment of new psychological forces. These latter elements reflect a
aspect that is addressed several times throughout this book. That is to say, they insist on what 'is
it has" and not in what has been "lost": the "lit lamp", "a new adventure",
the willingness to 'face the unexpected'. Among these elements, it occupies a place
expressive, special, and very powerful; a reflection that is ultimately a very definition.
decisive and assertive of psychological well-being: "and I will continue to love."
The loss of vision is not only faced with that deep 'self-verbalization' - 'and
I will continue to love, not only thanks to the practical support of social networks and
professionals surrounding the person involved. In less pedantic terms: isn't it
indirect reflection of the idea "and I will continue to love" from another complementary and very
"And they will continue to love me?" In the case of people who lose the
vision, the rehabilitation and psychological support tasks (which are carried out in Spain
excellent professionals, generally linked to the ONCE) have to complement
those that the family carries out with greater or lesser success, and that are part of the economy
from 'wanting'. Professional activities are necessary and often very
effective in their results. Furthermore, in the last two decades, the development of those
we could call 'technologies of perception' and 'technologies of knowledge' is
allowing access to resources that, for many blind people or those with deficiencies
visuals imply very radical transformations of the lived world and of the
possibilities of managing in it. The hope that advancements are not far-fetched.
technological advancements may produce, in the medium or long term, even more decisive changes.
On the other hand, the theoretical developments of the psychology of blindness are so
transcendence as the technological effects in practice (there is no better practice than a)
good theory," it is said in the evolutionary tradition of psychology). Today there is no
justification for psychological intervention, educational action or tasks of
rehabilitation with blind people is based on an uncritical and lacking empiricism
theoretical sediment. This book, which pays particular attention to the theoretical aspect of the
psychology of blindness, is the best demonstration of what I say. It is not only about
understand the phenomenological world of the person without vision, but rather to explain
rigorous form of its psychological functioning, within the framework of the developed models
for scientific psychology. In this they insist, and with good reason, the authors of the book: not
There are two psychologies, one for the blind and another for the sighted, but rather one single one, which has
to be able to explain the different forms of human development and experience.
It is obvious that, from a theoretical perspective, the case of people who present
absence of vision or significant visual deficiencies since the first months of life
it is very different from that of those with acquired blindness. When we reflect on the
apparent role of vision in development and about its very special "pregnancy"
experiential", it immediately raises "the question of what is happening
in the psychological development of children who have lacked vision from the beginning. The
human visual system, in its capacity as an instrument
biological registration of energies and knowledge of the world, is one of the technologies
more powerful, precise, and efficient developed by nature. To the seers, we
it seems that our world is irreparably and primitively visual. A world seen
first of all. The visual metaphors in our language well reflect that kind of
phenomenological primacy. What is seen constitutes the frame of reference with which one
ultimately evaluates the truth of judgments. Vision is presented to us as the
unappealable witness of the world. It seems to us that vision occupies an irreplaceable place in
our relationships with people and things.
However, the absence or significant deficiency of vision does not hinder
generally the proper construction of the human being. This is one of the issues
fascinating questions that it raises, from a theoretical point of view, blindness: how is it possible
that the loss of such a delicately and complexly cognitive system, of a world that
it appears as a frame of reference in ordinary seeing experience, it is not
devastating for the cognitive system as a whole? I remember what I
they surprised many years ago, the data from Alberto Rosa's doctoral thesis,
published later in an article (Rosa, 1981) about mental images in blind individuals
birth totals. They showed that there are phases of development in which the blind
they perform worse certain tasks that seem to involve active transformation of
images, but this does not happen definitively. As one approaches the age of
"Formal operations", the resolution was similar in the blind and the sighted. How is that?
Possible? What systems do blind people use to manage representations?
cognitive processes that seem to be functionally equivalent to the source images
Visual? And on a more phenomenological level, how do the blind manage to,
to use a language full of images and visual references meaningfully?
In theoretical terms, the psychology of blindness is filled with fascinating enigmas.
I also believe that the authors of this book, colleagues from the Autonomous University of
Madrid, they are people especially prepared to face systematically and
rigorous to those unknowns. The research tradition in the psychology of blindness in
the U.A.M. has been consistent for many years, thanks first of all to the
expertise, the ability to work as a team, and the ingenuity of Alberto Rosa and Esperanza
Fitting. And to the most recent contribution from very capable researchers like Huertas,
Blanco, Rubio, Espinosa, and Simón. The mention of these researchers and colleagues
It brings me to the second reason (not yet explained) why this prologue could not be.
objective. I think that the Psychology of Blindness is an important book. I believe
which it is, in the first place, because it includes an unprecedented effort to establish a framework
deep and comprehensive theoretical framework (see the last chapter) to organize a huge
dataset. Also because it reviews and critically analyzes many of these data
about the psychology of blindness, and why there are 'few precedents of this entity in
the literature on blindness in Spanish. It is, in my opinion, because it constitutes a
effort to integrate theoretical and research advances with practices of
Intervention with blind people. In my opinion, this is a book that was needed.
But... I also know that my judgment, in this case, cannot be dispassionate. When
I speak of the authors of this book, I speak of old or new companions, to whom we
apply the 'still wanting' from the poem. I hope that the reader wants to 'keep reading' -the
the book deserves it - beyond this prologue that could never hope to be
goal. And even cognitive psychologists sometimes realize that the
Reason does not always rule, and almost never lacks passions. 'Passion is blind,' it is said.
Traditionally in our language. It is also the reason almost always and, as
this book clearly shows, those blindnesses -like the others- must not be
considered as defects but rather
as alternative forms of human experience.

ANGEL RIVIERE
Chapter 1
INTRODUCTION. CAN WE TALK ABOUT A PSYCHOLOGY OF THE
BLINDNESS?
ALBERTO ROSA AND ESPERANZA OCHAÍT A

The book we are starting here aims to help remedy some of the gaps.
existing in the literature on the psychology of blindness, especially, although not only,
in the Spanish language. We, the authors, wanted to write a text that collects and
analyze exhaustively and critically the data and theories that we have considered most
important from a certain way of understanding the psychology of blindness.
As the reader will soon discover, this is not an eclectic general manual, but
facing a book that has a series of biases derived from both the history of the work of
investigation of the authors, as well as their own metatheoretical stance. With this we want to
to say that, firstly, the chapters that compose it -although treated from a
integrative and nondualistic perspective that avoids dissociating the realm of the affective
emotional of the cognitive - they have an orientation towards topics classically addressed
by the so-called 'cognitive psychology' and therefore mainly deal with
cognitive and instructional aspects. Secondly, and this is perhaps the
the most important characteristic of this book, it tries not only to describe but also to
Explain the psychological characteristics of the blind. All of this from a theory.
psychological that allows using the same principles. to explain development
psychological and learning in both people considered normal and
those that have some type of deficiency. A theory that, therefore, can explain
the psychological characteristics of blind people without falling into comparison
with the seers from naively 'normal or centrist' positions or
visual centrists
As the interested reader will know about the topic, it has not been published in Spanish.
no general manual dedicated to the psychology of blindness and neither does it
they have translated the few edited in other languages. And, undoubtedly, we can affirm that
they are scarce since we only have two review books prepared by authors
North Americans. Among the most recent, one of them, written by Warren in 1977
thoroughly reviewed by the same author in 1984, offers a complete review of the
literature on the topic from an eclectic perspective. The other, edited by Scholl
(1986c) is an eminently practical manual dedicated to development and education.
the visually impaired people. However, as reflected in the bibliography,
In recent years, a considerable research and applied effort has been made.
about different aspects of the psychology of blindness that has led to numerous
publications of considerable quality both in our country and abroad.
For all these reasons, the compilers of this book intend to gather that research effort.
through a review of that literature, discussing it critically from a
a determined theoretical framework. Thus, once the work is finished, we believe that the book can
to be especially useful for Spanish-speaking readers. As we have already said,
It is a unique general work published in this language about psychology.
of blindness. But it may also be advisable outside the scope of Spain and
Latin America since, as we just explained, the manuals we have in
other languages, specifically English, are not recent and have characteristics
quite different from those of this.
We will talk again about the characteristics of this book - its authors, the chapters that it
component and the audience to which it is addressed - in the last section of this chapter. But
First, it is necessary to reflect on its own object of study: psychology of
blindness. We think that a book with this title must address, from the beginning,
doubt about whether one can really speak properly of certain characteristics
defining psychological aspects of blindness. And this is because of the type of response that is given to such
the question conditions the character and content of the book. But, as the reader will sense,
this answer can hardly be clear or simple, since it can be answered in
affirmative or negative form depending on the conceptual stance adopted. Therefore
We dedicate the next section to clarifying and specifying why we have devoted a book.
to the psychology of blindness.

Can we talk about a Psychology of blindness?

We believe that one can always speak of a particular psychology of a group.

when this distinctly shares a set of elements considered as
relevant from the theory being used, whether they are those specific configurations
of the units of analysis, or particular modes of functioning of the principles
explanatory. With this we mean that we could talk about a psychology
specific to a "group X" if its members shared among themselves, but not with
other groups, some of the operational mechanisms necessary to develop the
specific actions to engage in social activities. We could
also talk about such psychology if the functioning of the explanatory mechanisms
of psychological development and learning outside characteristic of that group and different
for others. Therefore, we could only speak of a psychology of blindness if
let's specify clearly what the distinguishing characteristics of individuals are
without vision, what, as we have just pointed out, necessarily requires a stance.
theoretical.
On the contrary, if it is thought that psychology is a science that seeks to find
the explanatory mechanisms of behavior, and it is considered that these are common
for each species, then any human group shares with the others those
behavioral mechanisms and any subject would be "normal", since the
explanatory principles of their development and learning would be the same as those of
any other individual of the species. In this way, the object of study shifts
from the distinctive characteristics of the subject, towards the functioning of the processes
general psychological. That is to say, it then moves from a study focused on the
properties of an individual (or group), considered as an independent entity
and idiosyncratic, to the study of common processes that always occur under conditions
concrete and specific. In this case, it would not make sense, in principle, to talk about groups
different, for in each group, in each individual, those same would also appear
processes that are precisely the object of study of psychology.
In the first case, it would be about searching for what individuals (or the
groups) differ, while in the second the emphasis would be precisely on
what they have in common. The problem lies in trying to reconcile diversity with
generality, so that the general causal explanatory mechanisms that
let them explain not only the general trend of the population, but also,
the 'special' cases. In this way, interindividual variability could not be
only considered, in the methodological plane, as a consequence of 'errors'
to prorate through the use of statistics, but rather it would have to
explore the causes of that variability in order to enrich knowledge of
what is provided about general psychological mechanisms. The possible sources of
the variability in the human species is enormous. On one hand, there would be the differences
biological factors between some subjects and others. On the other hand, there would be macro factors and
microcultural, explainable from historical evolution, which can form
constellations of situations that create very different conditions for the
behavior. If we also consider that these two types of factors (biological and
cultural) interweave with each other in an almost inextricable way throughout life.
of each individual, as they grow in age and experience, we can give ourselves
account of the complexity of the task presented to the psychologist who intends to
precisely studying psychological functions and their development.
The comparison between groups is, then, one of the methodological strategies that
are useful to highlight the influence of one factor or another on the
construction of the psychological functions of humans. But it must always be taken into account
the caution to consider that the description of differences is nothing more than a resource to
clarify the influence that the factors whose variability is have on such construction,
precisely, the objective that is intended to be explored. Moreover, the theoretical study of the
factors that affect development and learning, at least from the perspective of
the authors of this text, it is not something that justifies itself for the amusement of a
group of intellectuals, but rather finds its meaning precisely in the utility that
offers when intervening in the genesis of those processes, with the final objective of
improve the living conditions of human subjects.
The interindividual differences caused by alterations in physical characteristics
of the individuals represents a privileged ground, both for the clarification of
the role that these physical characteristics play in general psychological functioning
of the subjects, in order to elucidate the resources available to the psychic apparatus and the
the way they use to cope with the demands of the physical and social environment,
taking into account, moreover, that the physical and psychic apparatus is not something given from a
fixed and finished form, but is subject to a process of evolution over the
life of each individual.
Vision is one of the most important perceptual resources we have.
humans. The consideration that the severe impairment of this sense alters in a way not
trivial the behavior of the subjects who suffer from it results in an affirmation of
common sense, but the way in which this condition affects the actual behavior of the
individuals in their relationship with the environment, and to the construction of their resources
psychological issues are something that is no longer so evident and which we believe is deserving of a
research effort, both for its theoretical and practical interest.
Characterizing blind or visually impaired subjects as a homogeneous group is
some problematic, as is evident in chapter 2 of this volume. Without
embargo, and with the precautions mentioned there, we believe it is justified to speak
from a psychology of blindness, at least in a tentative manner. In any case, the
subjects with severe vision impairments share a highly physical condition
idiosyncratic that undoubtedly has relevant effects on behavior for
any psychological theory that one starts from. On the other hand, there is a category
linguistics that designates these subjects, some institutional bases and a set of
instruments and social conditions that allow them to be considered as a group. All of this
there are reasons that justify considering blind people as a group whose
Psychology deserves to be studied. Moreover, it is necessary to justify the dimensions.
theories that allow characterizing this group. This implies exposing in some detail
a psychological theory, which we will dedicate the last chapter of this book to.
It will be through the presentation of the theoretical stance that we adopt as
we will try to justify the fact of talking about a psychology of blindness. But of a
psychology of blindness whose main objective is to try to explain the development of
psychic apparatus of the individuals that make up this group placing special emphasis
in the resources they have, and not precisely in those they lack. To
at the same time, this theoretical stance allows us to consider the psychology of the blind as
a variant of general human psychology that helps us understand a set of
possibilities of action of the psychic apparatus that do not manifest in individuals
seers. The comparison of the behavior of blind people and seers gives us
allows, therefore, to come to know the differential effects that vision has on the
human behavior.
A question arises when we refer to the linguistic label of 'psychology of'
blindness." Which is the normative group, that of the blind or that of the sighted? The
The answer to this question is not easy either. On one hand, if we are consistent with the
the position that we have been maintaining until now, we should reject the own
formulation of the question, since the objective of the psychology of blindness would be to study
the way in which human individuals who have seriously diminished support
visual sensory material develops its psychological functions and organizes its
behavior with the resources they have. The only negative statement that
What would be precisely that which constitutes the group (subjects who do not see), but that
denial would not serve at all as a causal explanation for his behavior, since
That would logically be inconsistent. The coherent thing, then, would be to talk about subjects.
normal with and without vision. The general mechanisms that regulate behavior would be
then prescriptively the same; and yet, the way in which some and others are
Adapting to the environment would necessarily be different, the way that would also be different.
take the development and learning process in individuals with and without vision.
But, on the other hand, there is an undeniable fact: the majority of the population is
seer and the culture and human ecological environment, in a very important part,
it presupposes that every human subject sees, and if they do not, that is considered not only a
important difference compared to other members of the species, but also something not
desirable for those who suffer from it. This has led to the development of a set of
resources to "improve" the condition of these subjects who are then considered
as "deficient" in relation to the norm. Blindness, or severe visual impairment, occurs
so it will be grouped, along with other physical or behavioral peculiarities,
within a general category of individuals who require special assistance for
to be able to adapt to the living conditions of the group to which they belong. Thus appears the
the idea of special education as something that society must provide for these individuals
reduced. The consequences, both theoretical and applied, of this process of
social labeling has a long reach, especially in the educational field, and it
extend beyond the specific case of blind subjects. Next, we examine
this issue with some care.

2. Defectology or special educational needs?

As we have mentioned on another occasion (Rosa, in press), in recent years there has been a lived experience
in the Western world in general, and in Spain in particular, a change in the
terminology used to refer to individuals who present some alteration
structural or functional - in their physical or psychological apparatus. Alongside the terminology
traditional, based on medical origin diagnostic categories, which still persists and a
of which the classification of the World Health Organization is made
(INSERSO, 1983) which distinguishes between deficiencies, disabilities, and disadvantages -see
chapter 2 of this volume-, a new designation begins to emerge for
referring to this type of people. Specifically, now we talk about 'Students with
Special Educational Needs. Some of the reasons for this change
terminology -beneath which rests a whole different conception from the traditional
regarding the processes of development and learning - they are recorded in the work of
Marchesi and Martín (1990) which has the eloquent title "From the language of the disorder to
"special educational needs". These authors point out that such a change of
vocabulary represents the shift of emphasis from the presumed defect of the subject to the
responsibility of the educational system that must face the problems of
learning that students of the type we are referring to may present. This
It clearly implies the acknowledgment that learning processes and,
the broad lines of development follow, in these students, the same principles as the
of the rest of the population. However, and in his own words, '...this new
conception does not deny that students have problems specifically related to their
own development. A blind, deaf child, or
a person with cerebral palsy initially presents some difficulties that others do not have.
partners. However, the focus is now on the capacity of the educational center
to provide a response to their demands (pp. 19-20). We, who subscribe
completely the spirit of the aforementioned work, we will focus more on this book in the
peculiarities that distinguish blind people from what they have in
common with the rest of human beings, albeit always from a psychological theory
what you consider to be the general mechanisms of development and learning are
common to the entire species. All of this because we must not forget that the objective of this
the book is to justify the particular way in which development and the
learning of the visually impaired in order to, from this basis, attempt to offer a
theoretically founded response to their special educational needs.
Undoubtedly, the reader will have noticed that until now we are making use
simultaneous of the two terminologies that we initially faced. In the title itself
this section talks about 'defectology' - (a word today in disuse, but
relatively widespread in the early century-, and that refers to a discipline that, in the
today's language, I would study the psychology and education of 'deficient' subjects or
with "special educational needs". However, we are not going to try to solve
this disjunction -which here refers to two clearly opposing conceptions
opting for one or the other, but attempting to create a synthesis between both, in a way
which, in some way, is already hinted at in the quote we mentioned earlier.
The danger of using linguistic categories such as deficiency, disability,
disability, subnormality, etc., is something already well known. It implies labeling.
of the subject, it can come to have a derogatory meaning, causing in others
feelings of pity and compassion, as well as frequently giving rise to the
social marginalization of disabled people. On the other hand, as I already pointed out
Vygotsky in 1927, the fact of talking about a person, about a child with a defect often
often interpreted as referring to a child who is missing something. A child
what
It has a normal development from which there is something to be subtracted and which, by its very nature
is incomplete. This conception of deficient individuals that Vygotsky already
it was considered unsustainable - it has undoubtedly had serious consequences on education of
the deficient people.
But referring to a child, to a subject whose personality is in formation, making
only emphasize that he has special educational needs can also, from
in our view, conceals some dangers. The main one, in our opinion, is
that some people, with the best intentions, seek to standardize development and the.
learning of students with different difficulties. Undoubtedly, the school of the countries
democratic should be open to diversity, and this becomes one of the
ideological justifications for integration, but that diversity must be recognized and
exploited, not ignored or marginalized when resisting the process of standardization
that necessarily involve the processes of enculturation that take place in the
school. There is a possibility that if a student does not respond to educational treatment
What is considered 'a priori' as adequate, its integration degenerates into a marginalization.
but, in this case, seasoned with social isolation. Therefore, it is necessary to have a
the most accurate idea of the peculiarities of development for each type of
affectation. In the case we are dealing with here, only by knowing the alternative routes that
Can development and learning continue when vision is absent or seriously impaired?
damaged, we will be able to adapt the educational intervention to the special needs of the
the blind. It is therefore essential that teachers, parents, and the community
social that surrounds the school becomes aware of diversity and takes advantage of it to
generate progress. The fact of knowing psychological development as well as the techniques
educational and instructional that can be used with blind people not only
it will improve their educational and social integration, but it is also essential for
understand the role that the visual system plays in the development and learning of
normal subjects.
From everything said so far, we can conclude that, when speaking of people who have
severe visual deficiencies, we have to navigate in a dialectic between two poles:
the heterogeneity posed by the different visual impairments they suffer; and the
homogeneity that represents that its mechanisms of development and learning do not
be different from those of the subjects called normal. We must also consider
another dilemma: should the school respect the rhythm and the "natural" characteristics of
development of the blind child? or should it rather "artificially" try to lead him through
the same paths to the levels of competence of their sighted peers? The
the issue does not lie in positioning oneself at the extreme poles of these two pairs of
apparent contradictions, but in how to integrate them coherently. Allow us
Now, to advance in this attempt, to break down some relevant concepts.
Let us start with the previously expressed homogeneity-heterogeneity polarity.
It deals with a dimension that, apparently, occurs exclusively in the individual plane.
People with any type of deficiency are still human beings, and,
as such, they have a physical and psychic apparatus whose innate rules of
functions are identical to those of the rest of the species. Its peculiarity lies in
that one or more of the 'interfaces' that connect you with the rest of the world are
damaged. This statement, which at first seems very simple, has consequences of
long range. Let’s think that each of the channels that carry the information or
"Sensory inputs" that reach the subject, as well as the responses ("outputs") with which
this acts on the physical and social environment, they are the result of a long process of
phylogenetic evolution that has left a whole structural and functional trace in the body
of each one
of the individuals of the species. Each organ has developed to fulfill a
function in the organism-environment trade, and, in turn, the development of tools
cultural factors that facilitate this trade in the case of human subjects presuppose the
normality for its use. Let’s also note that each of these channels of
communication has a specific mission: to serve as a vehicle for information
lighting, something central to develop in large spaces (sight); to allow the
sound reception, which allows alerting to the presence of objects outside the
visual field and, perhaps more importantly, communication (the ear); And
to move and take actions on the environment, whether motor or verbal (the apparatus
motor). But, in addition, each of them does not perform its functions in a way
independent, but are interconnected with each other, so that, for example, the
the perception of a certain sound causes, through an orientation reflex, that it
shift your head and eyes to try to capture the source of that sound, putting your
I manifest a pre-programmed intersensory coordination. Let's take a look, then,
that the damage of one of these channels affects not only the specific function that
supposedly he must comply, otherwise it has cascading effects on others and
about the functions that the perceptual system as a whole performs on the environment.
Taking the argument we have been developing to the extreme, it could be said that
an individual with a serious alteration in any of these channels as happens to the blind
with the visual channel - it presents a high heterogeneity concerning the other individuals,
It has a very serious "defect" in adapting to the environment. It is "missing" something that it has.
the rest of the species is "deficient." But despite that deficiency, it remains a
individual of the same species, the rest of its organism undergoes a process of
pre-programmed maturation and, based on the resources available and the type of
relationship established with the environment will involve a set of learnings about the
which will build its psychological development. Such development may take a form
highly idiosyncratic based on those two factors that we have just pointed out: the
physical condition of the subject -in our case the degree and type of visual impairment- and the
the way in which their interaction with the environment develops. Ultimately, a subject
deficient, like a blind person, may be different from others but, without a doubt, continues
maintaining many characteristics in common with the rest of the human individuals.
But the human species is very peculiar, and is fundamentally characterized by being,
among social species, the one that has developed communication to the highest degree
within their groups generating, from there, the language and culture. And this has
done to such an extent that it has completely transformed the environment in which it
develops, in such a way that its own ecological niche has been fully transformed
due to its action, in such a way that now it is completely artificial. The vast majority
The objects surrounding the subject are artificial, they are the result of transformations.
humans intentionally carried out by subjects through the use of tools
crafted within the context of a culture throughout history. The very human subject
has had to learn, both as a member of a cultural group -that has
constituted through the course of historical time -- as through its process of
growth and enculturation -in its life cycle as an individual-- to use those
cultural tools for action on the environment, which is no longer simply physical,
if not, and above all, social. This handling of cultural utensils, and the realization of the
social functions within the group, is what constitutes him as a human subject, what
brings out the higher psychological functions. The biological organism
becomes a human individual with consciousness and will. But this is not a process
biologically determined, although the biological structure has created the conditions
of possibility and has been restructured for this purpose throughout evolution, but it is
a process that takes place in the group using the instruments and methods for it
cultural actions refined throughout history.
Precisely this cultural development, this distribution of functions within the group
it is something that protects its members and helps them survive in the surrounding environment.
Without the presence of this cultural environment, that is, in the 'natural' ecological niche of the
hominids, a deficient subject would not survive, but neither could he do so in
solitary, none of the normals. It is the group, using the products that he himself
generates, what protects man from his environment, transforms the environment and, through
this process creates individual human subjects. But, in addition, each culture has
developed, in the course of its history, particular instruments to respond to the
type of environmental demands that must be faced, and this makes the systems
the personalities of the individuals that make them up can be very different.
Heterogeneity, therefore, does not find its source solely in the possible differences.
that may occur in the innate biological equipment, in the integrity or not of the
sensory or motor systems (in the cases we have been referring to), otherwise,
also, in the availability of the modes of action and the cultural artifacts that
they prepare the subject to meet the common action demands of their group
social. In all cultural groups there is a set of parenting practices and
instruction, informal or formal, specifically dedicated to producing the learning of those
skills. The school comes to constitute an institution historically generated to
to face this social demand.
It is precisely the theorists of the sociohistorical school who have concerned themselves with
study and explain the differences that may exist between development processes
through the enculturation that occurs in normal and deficient individuals in the
breast of the same group. And this starting from the consideration that the human subject is
the result of the fusion between a biological being and accumulated cultural experience.
We believe that the following statements by Vygotsky may be useful for
understand the peculiarities that development and learning may have
the blind within a certain society.
The normal child's attachment to civilization generally represents a unique alloy.
with the processes of its organic maturity. Both development plans, the natural and the
cultural, coincide and merge with each other. Both series of variations
they converge, penetrate each other reciprocally, and essentially form a unique series of the
socio-biological formation of personality. Since organic development is carried out
in the cultural environment, it becomes a historically biological process
conditioned." (1929, p. 22)
We find, then, that cultural instruction comes to be a process of
certain standardization of development, as the practices of parenting and teaching
they supply a certain material and a specific rhythm for it to be produced
fusion we have just referred to. But, what happens when a deficient child -in
our case an blind person - is subjected to the normalization process that represents the
education? It is expected that in such cases some mismatches may occur or
problems.

In the child with a defect, this type of fusion is not observed; both planes of development
diverge generally in a more or less ostensible way. The organic deficiency
serves as the cause of divergence. The culture of humanity has been created in
conditions of certain stability and constancy of the human biological type. That is why its
material instruments and adaptations, their devices and psychological institutions are
destined for normal psychophysiological organization. The use of these
instruments and devices implies, as a mandatory premise, the existence of intellect,
the organs and the functions proper to man." (Vygotsky, 1929, p. 22)
Later, he specifies:
The defect originated by the deviation from the stable biological type of man, to
to provoke the disappearance of some functions, the deficiency or the deterioration of the
organs and the more or less essential reorganization of the entire development into new
conditions, (...) alters the normal course of the child's rooting process in the
culture. Certainly, culture is adapted to the typical, normal man, to his constitution.
so that atypical development conditioned by deficiency cannot take root
in the culture in the same way as it takes place in the normal child." (ibid. p. 22)
We could think, based on these quotes, that people who have some deficiency
organic" and therefore -the blind are always and necessarily "deficient" in
comparison with normal calls. Nothing further from the idea that is intended
transmit here. As already mentioned, the basic processes of development are the
the same in normal and deficient. However, the resources available to them for
Adapting to the environment is different from that of normal ones, both in their physical dimension.
as in its social dimension. From a physical point of view, the visually impaired
they lack the visual system, one of the most important sensory channels with which
we count on human beings to relate to the environment. But also, if
we take into account the social dimension, blindness changes the situation of
individual in the group or groups in which they develop. In this sense, a blind child
generates different treatment from the people around them, treatment that often,
it may be deficient. It also generates different expectations for development and
learning that a sighted child. The challenge we face is the ability to
explain how the development of the handicapped occurs, in our case the visually impaired.
This will allow us to implement intervention programs that enable them
reach levels of functional development and learning equivalent to those of the
sighted population, as well as preventing the negative effects that blindness may have
about parents and educators.
We know, therefore, that the resources available to people with disabilities -and more
specifically the blind - to adapt to their physical and social environment are different from
those of the normals. We also know that the processes of enculturation are not
primarily designed to address the initial deficits they start with.
However, as will be analyzed throughout the pages of this book, these subjects
They reach levels of development and efficiency similar to those of the sighted.
It seems, therefore, that starting from a high level of heterogeneity regarding the
persons considered normal reach a high homogeneity in the
final result of their development process. In a strict sense, they have undergone a process
from homogenization through its process of enculturation. But that does not imply that the
the path that its development has followed is identical to that of others. On the contrary, it is
reaches functionally similar results through alternative pathways that involve the
reorganization of the human psychological system.
But to affirm that the development of deficient individuals can reach
equivalent to that of the normals, one must necessarily assume the existence of one.
certain redundancy in the capacities of the human organism. The functions that the
An organism must develop throughout its life, not structurally limited.
unmovably, but the system, based on the elements it has intact,
it can be restructured to be able, with different resources, to face the
demands of their environment. Again, we turn to the words of Vygotsky to explain the
possibilities of restructuring the psychic apparatus.
If any organ, due to a functional or morphological deficiency, fails to fulfill
completely its tasks, then the central nervous system and the psychic apparatus of
men take on the task of compensating for the defective functioning of the organ. They
they create a psychological superstructure about the organ or the deficient functions that
tends to secure the organism at the dangerous weak point. Upon coming into contact with the
The external environment gives rise to the conflict caused by the lack of correspondence between the
organ or the deficient function and the tasks it has to fulfill, which leads to a
high possibility of illness or mortality. (...) The child's positive peculiarity
with deficiency also originates in the first place not because some u disappear in it
other functions observed in the normal child, but because of this disappearance of the
functions give rise to new formations that represent in their unity a
reaction of personality to deficiency, that is, compensation in the process
of development. If a deaf or blind child reaches the same level of development as a child
normal, it does it in a different way, through another path, with other means, and for the educator
It is very important to know the peculiarity of the route by which he must lead the child.
The law of transforming less deficiency into more compensation provides
the key to reaching that peculiarity." (1929, p. 10-11)
This concept of 'compensation' that we have just quoted deserves to be commented on with
certain deliberation. It is a classical concept, but in Vygotsky it takes a
particular sense. It is not about achieving a specific psychological function
"compensates" another damaged one, because, in a certain sense, the specialization of each one of the
interfaces that relate the individual to the environment do not allow for their replacement.
It is not that a decrease in one part of the system produces a
hypertrophy of another, as is well known (and as will be analyzed in the chapter
3 of this book), sensory deficiencies do not lead to a significant decrease in
the sensory thresholds they have. Compensation refers, rather, to the
restructuring of the psychological system. According to the cited author, the
compensation must be understood as a reaction of the personality to deficiency
that, beginning new processes of rounding the development, replaces, superstructure and
balances psychological functions. The deficiency, therefore, causes the individual
create a new and peculiar type of development. The following paragraph clearly states that
compensation is, for Vygotsky, the result of the child's maladaptation regarding
its environment. The physical and social demands that it poses create the conditions
so that the compensation can take place.
The education of the child with different deficiencies must be based on the fact that
simultaneously with the deficiency, the psychological trends are also given
an opposing direction, the possibilities of compensation are given to overcome the
defect and precisely they are presented in the foreground in the development of the child and
they must be included in the educational process as its driving force. Structure everything
educational process according to the line of natural trends towards supercompensation
it means not to downplay the difficulties that arise from the defect, but to exert all the forces
for your compensation, present only the tasks and in an order that responds to the character
gradual process of the formation of the entire personality from a new point of view.
The most important thing is that education is supported not only by the natural forces of
development, but also at the final special point towards which it must be directed. The
social validity is the special final point of education, as all processes of
supercompensation is aimed at conquering social position. The
compensation is not directed towards a later deviation from the norm, even if it is in the
positive sense, but towards the supernormal development, unilaterally deformed and
hypertrophied personality in some aspects, but in the sense of the norm; in
the sense of approaching a certain social type. A certain social type of the
personality is the norm of supercompensation." (pp. 40-41)
Vygotsky's ideas allow us to overcome through a new synthesis the two
contrapositions we referenced in previous pages (homogeneity-
heterogeneity and normal development-artificial instruction) synthesis which, in turn, allows
also the apparent disparity between defectology and special needs. As
we pointed out, the deficient subject presents at the same time a high heterogeneity
regarding the norm in the initial resources it has to relate to the environment thus
such as in the development process and a high homogeneity in the ultimate goals of the
education and in the final competence that one acquires. This clearly leads to the
Education is structured through attention to special educational needs.
of the deficient so that the subject can achieve that compensation we refer to.
we have been referring to. For this, education must 'tension' all the resources of the student
and assist it both naturally and artificially with all the possibilities they offer
advancements in education and technology.
Therefore, in order for that overcompensation effect to occur and for the blind person to be able to
to achieve maximum social validity, it is necessary to know the resources available to the fullest.
It is available. Only by knowing how development and learning occur when the
visual system we will be able to implement special educational resources that
what blind children need. As the reader will find throughout the pages of this
book, the blind person has very important non-visual interfaces - especially touch and
the ear - which allows them to communicate with their environment. Therefore, from the earliest stages
great effort must be devoted to the people around the child
understand those non-visual forms of relationship with people and with objects. and
they can create realistic expectations about the blind person's ability to adapt to
society. This is how they will allow the blind person to build their development through
the alternative routes available, activating the compensation processes.
The Vygotskian concept of 'instrument of mediation for action' is very useful.
to understand how these compensation processes occur in people
deficients, as well as to explain the role that they can play in such processes.
artificial instruments that technology provides us. As we have pointed out
previously (Rosa et al. in press), the communication interfaces with the environment
they are, in their own original sense, instruments of mediation. In this sense, it is necessary
to point out that the visually impaired have the most mediation instrument
important that has been developed by the human species: language. As the reader
you will get to know as you delve into the pages of this book, the language will
to have a
very important role in allowing to compensate or restructure the psychological system of
the blind. Language thus constitutes an instrument of mediation that, for a
side, allows to explain a large part of the peculiarities or heterogeneity of development and
the learning of the blind. On the other hand, language is also the main
responsible for the processes of homogenization and enculturation that allow these
subjects manage to build a psychologically functional system equivalent to that of the
seers.
But it is also possible to think that the use of artificial instruments could replace, to
less functionally, some of the seriously damaged natural instruments or of
those that the deficient lacks. Artifacts today as common as glasses, magnifying glasses, the
headphones, Braille notation, wheelchairs, or automotive developments,
informatics allow to bypass defects and make subjects with some type of
anatomical problems cannot be considered deficient in any way.
The question lies, then, in designing the precise technological instruments to
achieve that functional efficiency and develop, at the same time, the methods
educational for sequencing the training in its use so that the level is achieved
desired efficiency end.
There are numerous cases of individuals seriously affected (blind, deaf, deaf-
blind or paralyzed) who have not only been efficient people but also eminent.
The economic empire recently built by the blind in Spain through
the ONCE is a paradigmatic example of that efficiency. If we maintain a
irremediable defect idea, how can we explain these cases? On the contrary, if
we uphold development theories that necessarily rely on the intact existence of
these interfaces for the construction of a psychologically developed adult, how
Can we also explain these cases? Certainly, we need theories of the
development that can explain this diversity by resorting to mechanisms
commonalities shared by normals and deficient individuals. Theories that are able to combine
a maximum heterogeneity within a maximum homogeneity, which explain the
differences arising from the same mechanisms that produce them in very different cases,
referring not only to the comparison of subjects with different types of deficiencies, but
also, in very heterogeneous social or cultural conditions.
We will try to tackle this challenge throughout the various chapters of this volume.
and, more specifically, in the last one. For now, we will limit ourselves to putting forward some
requirements that we believe a theory of this type should meet, making use of
Hello from theoretical instruments that some of the theories currently offer us.
available.
First of all, it is necessary to consider a priority theoretical requirement. The way of
explanation of development in normals and in subjects with special needs must
be coherent. There should be nothing in the explanation of development and learning of
the deficiencies that are not present in the normals. Nor should they be offered either
explanations of the development of the normals that force the need for 'ad hoc' explanations
for the deficient. Ultimately, we need development theories that are capable
to explain the heterogeneity.
On the other hand, and as we have already pointed out, the development of the deficient is not development.
normal but missing parts, rather it is a qualitatively distinct construction.
This implies avoiding something that we would dare to call 'normalcentrism' (something like
like a version of cultural ethnocentrism but applied to 'different' subjects.
This necessarily leads us to defend a constructivist approach.
But when we talk about constructivism, it implies that something is being constructed, and that,
Generally, it is done in the presence of a plan that necessarily includes a
final meta. When we talk about constructivism to refer to a theory of
Human development raises some unsettling questions: what is the plan of
development?, where is its goal? Kessen (1984) addresses it from the psychology of
development and from the theory of contemporary science an attempt to respond to these
questions. From your point of view, psychological notions are starting to regain strength.
that dispel the idea of a final goal of development specified 'a priori' of some
manner (for example, through the evolution of the species), to emphasize the notion
that the changes that occur with age are not pre-established goals, but the
result of a succession of fortuitous or intentional circumstances. Like him
says, a kind of resurrection of Watson's vision in a strange marriage with that of
Vygotsky. Consequently, the state of the subject throughout their development must be
to explain oneself by the causes that produce it, and not by the existence of pre-
established. This does not imply that there are no goal-states to explain in the theories of
development or to produce through education at a specific historical moment,
but these are contingent constructions, which raises interesting problems
morals and politicians.
In any case, this does not imply, in any way, the end of the theories of
psychological development in favor of learning theories. On the contrary, what
means that they must face different challenges. Among them the
recognize that the developing subject is an open system, without a predetermined end, and
whose intrinsic mechanisms produce learning under conditions of restriction to their
action in specific contexts, from which development occurs. Theories
of this type would accept diversity, both in terms of different states of the
subjects, as well as the different mechanisms that produce them (in relation to the conditions
in which they are applied). Thus leaving the development processes open to changes
cultural events that occur in human history, which relativizes the changes
normative. And, perhaps most importantly, it raises ethical dilemmas regarding the
specification of the part of the development, presumably quite large, that is not
predetermined by biological evolution.
Ultimately, there is no more teleology in development than what is imposed by a
more or less conscious intentionality, the human subjects that study or that
they produce development. This implies that it is open to our action within
the margins of the resources we have. Our theories can no longer be
regulations in an absolute sense with reference to the objectives of development, but rather
contingents regarding the historical moment we are living in. The development of children
it is open to the actions that are carried out with them and has no other pre-established purpose
that we are capable of presenting and implementing.
A view of development like the one we have just presented must necessarily
include within it direct prescriptions for educational intervention. Something that
it is very much in line with Dewey's pragmatism or practical psychology that
Vygotsky advocated (1982b). Furthermore, according to him, the success or failure of the
the practical application of a psychological theory is the fundamental criterion for validation
empirical. However, to do this, it is necessary to specify, in some way, both the manner
in which one acquires and progresses in the mastery of certain skills especially
relevant, as well as what path development follows in the case of the subjects who
they suffer a
particular type of deficiency (in this case blindness) within a set of
clearly specified environmental restrictions. This is something we will try to do
in the following chapters.

3. Book plan and reader's guide

This book is divided into seven chapters dedicated, precisely, to those topics that
we have considered more important for the study of psychological characteristics
of blind people. Each one of them is built in an attempt to reconcile the
theoretical relevance and scientific rigor with an accessible form of expression for
all audiences. Thus, we can say that the book is intentionally written,
for the most part, clearly and not excessively academic. With this we have
intended to be useful not only to professors and university students, but
also and mainly to the people who deal daily with education of
the blind: teachers, caregivers, rehabilitation technicians, parents and, in general, to
all people interested in the psychology of blindness. All the chapters have
have been drafted taking into account not only the theoretical aspects but also those
practical issues that the authors have considered most relevant. Therefore, it has been
trying, as much as possible, to specify the development processes and
learning that needs greater educational intervention, as well as the instruments
of evaluation and intervention that can be used.
The chapters, whose content we will briefly describe below, are
arranged according to an intentional order that responds to its own definition of
blindness as a sensory deficiency. Consequently, after this first
introductory chapter that aims to justify the content of the book, is dedicated to
two to the description of the biological and perceptual characteristics of the blind.
Subsequently, an extensive chapter studies the effects that these characteristics have on
the psychological development of these subjects. Chapters 5 and 6 offer the reader a
extensive review of those aspects in which the perceptual characteristics of the
the visually impaired have greater impact and, as a consequence, hinder integration more
the blind in society: mobility and spatial knowledge and access to
written information. The last chapter carries out a critical synthesis of the information
contained in the rest of the book from a certain metatheoretical stance.
Let us now analyze in some detail the content of the following
chapters. The second, Characterization of blindness and visual impairments, aims to
delimit the field of study of the book, which means defining what is meant by
blindness and visual impairment. To do this, first analyze the different
dimensiones de las deficiencias visuales: tipo de transtorno, gravedad, etiología,
evolution, forecast, moment it manifests, etc. Subsequently, it examines the
incidence of visual impairments in the population as well as diseases and
causes that produce them. Below, the reader is provided with information about the
main biological and functional characteristics of the visual system to study
after their most important diseases. The chapter concludes by emphasizing
the applied aspects related to vision assessment and the possibilities of
intervention for the utilization of visual remnants.
Chapter 3, Perception without Vision, is dedicated to the study of sensory systems.
what the blind person has at their disposal to know the world. To this end, the authors analyze the
anatomical and physiological characteristics of those systems as well as the way in which they
used in the absence of vision. The information in the chapter is organized around the
perceptual systems that have greater functional relevance for blind people and
visual impairments: somatosensory, vestibular, and auditory. Less space is dedicated to
taste and smell, not because they play a secondary role in understanding the world
on the part of the blind, but because they are sensory systems that do not reorganize
importantly in the absence of vision. The authors have followed the same order
for the study of the different sensory systems. First of all, they describe, both to
anatomical as well as physiological level, the receptors, the pathways, and the nervous centers
assigned to the information that each of them captures and, subsequently, analyze the
way in which the blind use these systems to access the objects in their environment.
The chapter concludes with a section dedicated to reflecting on the phenomenology of the
blindness, that is to say, on the effects that the perceptual experience of the blind can
to have about their way of knowing the world.
The following chapter, Blindness and Psychological Development, is dedicated to the study of the
peculiarities of the development and learning of the blind from birth to
adolescence. It attempts not only to describe but, above all, to explain the pathways
alternatives that, from the early stages of life, the child can use to
build its development in the absence of vision. It also seeks to place
manifesto, the importance it has for the development and learning of children
blind the ability of the people around them to understand their ways not
visuals of relating to the outside world. The chapter is structured in four
large sections that follow the classical organization -by stages or periods- that is
habitual in studies on development. The first one is dedicated to early childhood,
that is, to the stage between birth and one and a half or two years,
studying the development of practical intelligence, motor development, and training of
the first affective relationships (attachment). The second section deals with studying the
genesis of images and, above all, of symbols in the absence of vision,
placing special emphasis on the development of preverbal communication and language.
The last two sections focus on the study of development and learning in the
school age and adolescence. Throughout the entire chapter, the author has been
pointing out those aspects of the development and learning of the blind in which
greater educational intervention is needed both concerning children and in relation to
adults around them.
Chapter 5 Mobility and spatial knowledge in the absence of vision is divided
in seven sections through which it is intended to study how they are carried out
transactions between the individual and the surrounding space when vision is lacking or is
severely damaged. The first one reviews the sensory systems involved in the
collection of spatial information in the absence of vision. Subsequently, the authors
they analyze the most important aspects of orientation and mobility in people
blind, the different techniques that are used to improve that mobility as well as the
instruments that can be used as aids. Subsequently, the ...
Characteristics that spatial representations can have when the system is missing.
visual. The fourth section is dedicated to the study of the development of spatial knowledge
in
blind children and adolescents, while the fifth attempts to make an analysis of
the most important factors that influence the spatial representations of these
individuals. The various procedures that can be used are reviewed below
for the blind to communicate their own knowledge to others and
spatial representations. Finally, the authors analyze the implications that the
studies on mobility and spatial representation have for teaching
geography for blind and visually impaired students.
The following chapter, Reading in the visually impaired, examines in a
exhaustive the form taken by access to written language when vision is lacking or
is severely damaged. It is divided into five sections, the first of which is
It is responsible for indicating the importance that the mastery of language has in our culture.
writing. The second one begins with a review of the different procedures of
tactile reading that have been created throughout history, to later pass to
describe the characteristics of the braille system. The authors then study the
psychological operations that are activated when individuals carry out the
tactile reading activity using braille. To do this, they analyze the movement of the
hands in the reading, perception, and coding of the tactile information that this
The system provides, the influence of the context, as well as the reading speed. The
section 4 is dedicated to educational and applied aspects: teaching of the
braille literacy, assessment tools and technical aids for reading
blind and visually impaired. The chapter ends with a reflection on the processes
involved in the tactile reading of Braille and about the differences that exist between them
processes and those that are set in motion in visual reading.
Finally, chapter 7, Psychology of blindness and general psychology, offers the reader
a general compilation and an interpretation of the data provided in the chapters
precedents. Therefore, it is about revisiting the question of whether or not there is a
psychology of blindness and trying to address it considering the information
contained in the rest of the book. It is divided into three main sections. The first one is
dedicated to exposing, with some detail, the metatheoretical stance that the authors
adopt for the interpretation of the empirical and theoretical data that constitute the
content of the different chapters of the book. Subsequently, in the second section, it
carry out the critical interpretation of each of those chapters in light of the theory
previously exposed. Finally, the authors make a general reflection on the
meaning of the information contained in the book from both perspectives
theoretical as well as practical, adding, at the same time, certain considerations
methodological.
The chapters that make up this book have been written by different authors and,
In that sense, it is a work of compilation. But it is a highly selective compilation.
hindered by many years of collaboration in the study and reflection on the
psychology of blindness. The compilers started nearly fifteen years ago a line
research on the topic that has been incorporated over the years,
the remaining authors of the book. Thus, the different chapters have been written by
those team members who have worked the most on each of the topics they
component. Of course, the signatories of each chapter are responsible for their
organization and writing, but the work of researching sources, the elaborations
Theoretical frameworks and general ideas that are discussed are the result of the discussions throughout the
group. For all these reasons and using Wertsch's (1991) terminology, it would be very difficult
answer the question what voice is speaking? referred to each of the
themes covered in this book. It would also be quite an irrelevant issue since
the important thing is the message they can convey to the reader and, above all, that this
message can lead to actions that, more or less directly, benefit the
blind people.
We would not want to end this chapter without expressing our gratitude to a good number of
people and institutions that have made this book possible in one way or another
could come to an end. The Center for Educational Research and Documentation (CIDE),
in its plans XI and XII, it funded and published our first research on
psychology of blindness and the subsidies obtained from the General Directorate of
Scientific and Technical Research (DGICYT PB85-0278 and PB90-0201) has us
allowed to have the necessary means to continue the work. Emilio Fernández
Lagunilla has been part of the research team since its inception and has collaborated in
the preparation of the book. Pedro Eguren, Juan Carlos Gómez, Fran Hagstrom, Mar
Mateos, Ignacio Montero, Angel Riviere, Pilar Soto, and James Wertsch read some
chapters and they made very valuable suggestions to us. Publishers such as American
Foundation for the Blind, Debate, British Journal of Developmental Psychology,
National Institute of Social Services, McGraw-Hill Interamericana de España and
National Organization of the Blind (ONCE) has given us permission for reproduction
of some of the tables and figures contained in the book.
Lastly, we want to express our gratitude to blind people, especially
to the children, who have always kindly allowed us to move forward in our
work. They, to whom we dedicate this book, have been and continue to be the source
main motivation for writing it.
Chapter 2
CHARACTERIZATION OF BLINDNESS AND VISUAL IMPAIRMENTS

ALBERTO ROSA

A book intended for the study of the psychology of blindness must include an attempt
definition of what the scope to be addressed is. This is precisely the
objective of this chapter. We will try to clarify what we understand by blindness and
visual impairment to detail our conception in the rest of the chapters
what is the psychology of blindness.
Most people consider that a blind person is someone who lives in a
total darkness. However, the vast majority of blind people have some degree of
functional vision although in severe cases it is limited to the vision of light, shadows or
objects in motion. Only a limited percentage do not reach any sensation
visual (10% of the population considered blind, according to Kahn and Moorhead, 1973;
or about 20% of children considered visually impaired, according to Hartfield, 1975.
Cited by Scholl, 1986c-). We find that blindness is a type of
sensory deficiency that follows a continuum from relatively mild disorders to
a total visual impairment. Therefore, when referring to the consequences
psychological effects of lack of vision will need to specify exactly what type of
visual problems we are facing.
In any case, the decrease in the contribution of visual information causes the subject
to be forced to depend to a greater degree than the general population on
the information provided by other senses. In this sense, the world
The phenomenology of the blind is qualitatively different from the world of the sighted. Touch
takes on a predominant role in the knowledge of the nearby environment, while
that the ear begins to act as a teleceptor taking on a role that far exceeds
the one who performs in the case of the seers. Even senses like smell or the
thermal sensitivity, which provides relatively little useful information for the
Vivid resident of a current urban environment, their relevance increases in the case of
blind person.
Ultimately, visual impairment affects perceptual functions, but, through
the adjustments that occur in them can affect the way of
functioning of other psychological processes. How they do it depends largely
part of a set of factors that we will now address.

Dimensions of visual impairments

There are several relevant dimensions when it comes to taking charge of what they are
problems faced by a person with visual impairments. Among them
they are the type of disorder and its severity; its etiology, evolution, and prognosis; the
moment when it manifests; and whether it comes or not as part of a constellation of
broader problems. In this last case, many times it shouldn't even be talked about.
disorders associated with blindness, but they must be carefully considered the
various impacts that appear together and weigh their psychological importance.
Let's think, for example, of the case of a person with brain damage who is
manifest at a motor and sensory level. We could hardly
talking about blindness with cerebral palsy or associated intellectual disability,
considering these last two as additional phenomena to blindness. It would be about,
rather, of a subject with a set of deficiencies each of which has a
importance in itself and that must be considered together when addressing its
case.
The functional consequences of visual impairment at the psychological level can be
very different depending on the position of a subject in each of the dimensions a
the ones we have just referred to. Note that the consequences of total blindness
birth can be very different from that of an acquired condition at times
later stages of development. In the first case, the processes
psychological processes will be developed using non-visual pathways for accessing information of the
environment - what, as we will see in later chapters, poses a mode of development
peculiar-, while in the case of a visual impairment that arises later,
those processes may already be established and the problem is how to implement them
I finish with information coming from other sensory modalities.
Alongside these dimensions, which originate from organic disorders, there are others of
social type that adds even greater variability to the population of the disabled
visual. Obviously among these last ones are the factors that produce variability in
any population, such as educational or socioeconomic level. But there is another
aspect that in the case of any deficiency is especially important, we
we refer to the expectations and attitudes of others regarding disability. As
Scholl (1986) points out that blind people, like any other human subject, tend to
to absorb the attitudes that others have towards him, so that if these are
negatives tend to behave consistently with the social role that is assigned to them
wait. In fact, one way to intervene with individuals with disabilities is the
performance regarding the image that the people around have of that deficiency and
about the subject's own self-concept.
From what we have just said, it follows that it cannot be reduced in any way
psychological state of a subject with visual impairments according to the type and severity of their condition
visual problem, but all dimensions must be taken into account.
we have just referred to.
There is a set of commonly used concepts that are used with some profusion when
referring to subjects with some organic impairment. Such are the terms of
"deficiency", "disability" or "handicap". These terms are not synonyms, but
that have a precise meaning within the terminology of the World Organization
of Health
and we find it interesting to focus on them. .
Deficiency refers to abnormalities of the body structure and of the
appearance, and the function of an organ or system, whatever its cause; in
deficiencies represent disorders at the organ level" (INSERSO, 1983,
p.40).
Blindness and other visual problems are classified by the WHO as 'deficiencies'
of the organ of vision" classifying them into the categories that we collect below:
Deficiencies in visual acuity.
Absence of eye.
Profound visual impairment in both eyes.
Profound visual impairment in one eye with reduced vision in the other.
Moderate visual impairment in both eyes.
Profound visual impairment in one eye.
Visual field deficiency.
Other deficiencies of various types.
Each of these categories is identified by a code and includes a group
of subcategories.
Disabilities reflect the consequences of deficiency from the point
from the perspective of functional performance and individual activity; disabilities
they represent, therefore, disorders at the individual level. (INSERSO, 1983, pAO).
Within the classification of disabilities, the "disabilities for
see", which includes as subsections disabilities for overall visual tasks,
in detail, to see and similar activities, for reading written language, or for the
lip reading. These disabilities are part of the 'disabilities of
communication," which implies that visual impairment, in some cases, could come
accompanied also by disabilities of other types (see INSERSO, 1983).
The "Disabilities" refer to the disadvantages that the individual experiences as
consequence of deficiencies and disabilities; thus, the disadvantages reflect a
interaction and adaptation of the individual to the environment" (INSERSO, 1983, pAl).
As this definition suggests, it is difficult to establish 'a priori' what the
disabilities that may appear associated with a specific visual impairment, since
that the disability depends not only on the deficiency itself but also on education
or social circumstances. In addition, it is necessary to point out that the adaptation of
the environment can reduce the degree of disability of a person.
If we follow Lowenfeld (1981), blindness imposes three types of basic limitations on
an individual: a) limitations in the breadth and variety of experiences; b) in the
ability to move; c) in controlling the environment and oneself in relation
with him. However, Scholl (op. cit.) points out that the importance of each of these
limitations are very variable depending on dimensions such as those we have mentioned more
up.
Precisely the distinction between deficiency, disability, and handicap that we just
to cite highlights that the functional capabilities of a certain subject do not
they come directly determined by the type and degree of deficiency, but
they can be remedied, to a more or less complete extent, through instruction
of skills and through the use of technical support instruments. This is an aspect
important to which we will refer throughout this volume.
We find, then, that instead of blindness, which is a generic concept and
not very precise, we should talk about visual impairments, or better yet, about
disabilities and impairments of each individual, which depend not only on their deficiency
organic
but also of the action skills that have been acquired and that can be
modifiable depending on the technical aids and the instruction they receive, as well as
the modification of the environment in which they operate.
Therefore, we believe that in the specific field of education, it is preferable,
paraphrasing Marchesi and Martín (1990), abandoning the language of disorder and moving to
the consideration of special educational needs. That is, instead of
consider disability as the natural consequence of deficiency, consider
what are the educational actions and technical aids that allow to remediate those
disabilities. It is not just a matter of emphasis, but it entails a radical turn.
both in the theoretical conception of the effects of deficiency and in practice
educational with these subjects, as instead of considering limitations from the outset
for the development of action skills in the environment, one faces the challenge of
design methods and instructional techniques that allow the individual to learn strategies for
action and take advantage of its resources to be able to perform, through procedures
different, functionally equivalent actions to those carried out by the subjects
seers.
The approach we hold here is in line with the rejection of the notion of "pathology" to
the time to refer to the behavior and development of these subjects. On the contrary,
we believe that the study and treatment of visually impaired individuals should focus not
not from its comparison with the so-called normality, but from a perspective that has
consider the originality that comes from not having or being seriously affected by a
sensory modality like vision. The problem then is not limited to describing in
what are different from the seers, but must explain the reason for these differences.
To do this, it is necessary to clarify what sensory resources they have available.
how they develop their knowledge processes and personality from them and what
Teaching and instruction systems can help them become more capable.

2. Prevalence of visual impairments: Some statistical data

In this section, we will examine the incidence of visual impairments in the

population, focusing on some indicators for its distribution.
It is difficult to clarify both the absolute number of visually impaired individuals that exist in
Spain as its prevalence rate in the population. The figures that they offer
publications from different organizations differ from each other.
In the Spanish case, membership in the National Organization of the Blind (ONCE) may
to be a good indicator of the number of blind people, as membership in this organization
represents a set of advantages (education, work, income, etc.) that make it very
attractive. To be able to join ONCE, one must meet the requirements set by the
law, that is to say, 'one must have a maximum visual acuity lower than 1/20 of normal in
both eyes with permanent and incurable character" (Alvira, 1988). The number of affiliates
According to the census conducted in 1987, it is 31,124. However, the fluctuations in the
affiliation over the years leads one to think that the actual number of blind people that
exists in Spain exceeds these figures.
Although there is no comprehensive census of disabled people in Spain, the National Institute
of Social Services (INSERSO) provides some estimates. Table 2.1 shows the
total number of disabled Spaniards estimated in 1985 and their prevalence rates.

TABLE 2.1.-Estimated number of disabled people in Spain in 1985

Type of deficiency

Number

Prevalence rate per 1,000 inhabitants

Sensory disabled Visual impairments Hearing impairments

Physical Motor Disabilities
Cerebral palsy Other conditions
Psychically disabled.

Source: Activity report of INSERSO, 1985, p. 15-16

Regarding the distribution of blindness by age, table 2.2 collects
data from various institutions.
Table 2.3 shows the age of onset of vision difficulties among members.
from the ONCE classified into different age groups. It should be noted that 44%
these subjects have visual problems since birth. On the other hand, 23% of
The affiliates present family histories of eye problems. Table 2.4
collect the distribution of these family backgrounds by types of affection.

TABLE 2.2.- Rates of blind people by age in Spain according to different sources
Source: Alvira (1988), p. 20

TABLE 2.3.-Age of onset of vision difficulties among the affiliates

ONCE expressed in percentages

Total number 24,297

Age ° Years 44%
From 1 to 15 24%
From 15 to 64 31%
More than 64 1%

Taken from Alvira (1988), p. 125

TABLE 2.4.-Family history of eye problems

Myopia Cataracts Glaucoma Others

37% 29%
6%

Source: Alvira (1988), p.123

We do not have Spanish data on some aspects that we believe are of interest.
pick up here, so we are going to provide some taken from sources
North Americans.
Table 2.5 shows the distribution of percentages of legal blindness in the
North American population classified by their various etiologies.
As can be seen in Table 2.5, 39% of legal blindness cases
in the United States is due to accidents. Table 2.6 shows the products that
they have caused more eye accidents in the North American population.
Finally, we will refer to some data, also American, about the
visual impairment and its co-occurrence with other disorders. These data belong to
different
sources and refer to non-overlapping time periods, so they must be
interpreted with care. Nevertheless, we consider it interesting to collect them here to
that the
the reader can create their own context. In the table '2.7' it is collected
some data about the North American population of individuals between 3 and 21 years old.
special education and related services during the 1983 academic year
1984, referring to some types of deficiency that are of interest here.
TABLE 2.5.-Percentage distribution of legal blindness in the U.S. (1978)
classified by age and sex according to their etiology
Age Sex

Source: National Society for the Prevention of Blindness: Vision Problems in the U.S.:
Data Analysis. New York, 1980.
Cited by Ward (1986), p. 46

TABLE 2.6.- Most dangerous products for all ages and for each group of
age. North American data from 1977

Product Number of % of total

ocular accidents in each group
All ages
Metal objects 24,609 9.04
2. Contact lenses 17.559 6.7
3. Vehicles 8,294.2
4. Chemical products 6.950 2.7
Sports
6. Cristales 6.240 2,4
Total 262.112 100.0
Less than 5 years old
1. Cigars and pipes 2,278 9.3
2. Hangers 771 3,1
3. Beds 720 2.9
4. Toys 648 2.6
5. Tables, cutlery 625 2.5
6. Vehicles 584 2.4
Total 24.616 100.0
5-14 years
Sports
2. Pencils 1.767 3.8
3. Metal objects 1.759 3.8
4. Crystal 1.649 3.6
Total 46.269 100.0
15-24 years
Contact lenses 10.797 13.4
2. Metal objects 8.544 10.6
3. Lámparas solares 3.299 4,1
3,131
5. Welding equipment. 2.219 2.7
Batteries 2.166 2.7
Total 80.856 100.0
25-64 years
Metal objects 13,900 13.2
2. Contact lenses 6.093 5.8
4,179 3.9
4. Chemical products 3.324 3,1
5. Batteries 3.061 2.9
 Total 105.694 100.0
Source NSPB: Vision problems in the U.S.: Data Analysis. New York, 1980. Cited
by Ward (1986), p. 47

TABLE 2.7

Type of deficiency
%
Total
Visually impaired Deaf-blind Multiply disabled

4,333,558
31.531
2.492
67.189

100,00 0,73 0,06

1.55

Source: Scholl (1986a). p.32

Previously, we mentioned the difficulty of estimating the exact number of disabled individuals.
existing visuals. This is added to the fact that there are multiple deficiencies in the
that blindness comes accompanied by other problems, so these subjects may
to be classified within other categories. Scholl (1986b) points out that some reports
seem to indicate that up to a third of the visually impaired population of working age
Students have, at least, some other deficiency.
Graham's work (1966, cited by Scholl, 1986b) provides the only data that
we know about the distribution of these deficiencies within the population of
blind people. This author conducted a national survey in the U.S., estimating for
then a total population of multiply disabled blind students of 15,000
subjects, although the sample from which data were collected consisted of only 8,887
students. Two-thirds of them had two deficiencies, while approximately the
40% had three or more. The total frequency of deficiencies found in this sample.
it was 21,766, of which visual impairment is already excluded. Table number 2.8
collect its distribution.

TABLE 2.8.- Other disorders that co-occur with visual impairment. Data
North Americans from 1966

Source: Graham (1966). Cited by Scholl (1986b), p.138

The extrapolation of these results to the Spanish population is problematic, all

since the dates of the different jobs and the prevalence rates they offer
different sources are discordant. However, we believe that the figures we have
managed will allow the reader to get an idea of the extent of the impact of the
visual impairment and its co-occurrence with other problems.
3. The vision and the visual system
The aim of this section is to present some information about the functioning of the
visual system as a whole, in order to make the different ones understandable
visual impairments resulting from damage to different parts of the organs of
the vision. Our interest is in making the functional problems understandable that
they can influence the functioning of perception. In no way do we intend
to make a thorough treatment of the structures and physiology of the visual system, neither
nor of the perception in this sensory modality.

3.1. The visual system

The visual system is a complex apparatus that is basically made up of the eye, by
a set of nerve pathways and structures of the central nervous system. The figure
2.1 outlines a simplified scheme of the components of this system with an emphasis
especially about the nerve pathways both afferent and efferent.

FIGURE 2.1. Diagram of the optical pathways. (Delmas, p. 177)

The eye is the organ responsible for receiving light information. The eyeballs
they are included in the cranial bone cavity and on their outer part they are protected by the
eyelids. Six muscles provide movement to each eye to direct the gaze in the
desired direction. At the top of each orbit are located the glands
Lachrymal glands whose secretion lubricates and protects the eye and is drained through the tear sac.
towards the nose.
Figure 2.2 presents a simplified diagram of the anatomy of the eye.
The back of the eyelids and the visible white part of the eyeball are
covered by a mucous and transparent membrane called conjunctiva.
The outer part of the globe is made up of a fibrous and white layer called
sclera and another transparent one called cornea. Behind them is the fovea, formed
through the choroid, the iris, and the ciliary body. The main function of the choroid is the
vascularization of the other structures. The iris is an anterior extension of the ciliary body
with a central opening called the pupil that varies in size acting as the diaphragm
of a camera. The ciliary body forms the root of the iris and serves to regulate, by
through the zonular fibers, the size of the lens during accommodation.
The lens, whose function is to focus the rays of light that reach the retina.
eyes, consist of a biconvex structure, non-vascularized, colorless and almost
completely transparent. The action of the ciliary muscles is what causes it to vary.
its shape and increase or decrease its refractive power. The lens is in front of it.
aqueous humor and behind it the vitreous humor.
Aqueous humor is a clear liquid with elements similar to those found in the
blood plasma although with different concentration. It originates in the ciliary body and is
evacuated through the Schlernm channel. Therefore, if we look at figure 2.2, fill in the
the posterior chamber located behind the iris, and the so-called anterior chamber located between
the iris and the cornea. The sense of its circulation - something important to understand the
glaucoma- goes, therefore, from the inside out.
FIGURE 2.2. Structure of the eye. (Ward, 1986)

The vitreous humor, wrapped within the hyaloid membrane, constitutes two-thirds.
of the weight and volume of the eyeball. It is located behind the lens and by
in front of the retina and the optic disc. Its composition is 99% water while the
The rest is made up of other components that give it a gelatinous consistency. Not
it is vascularized, lacks elasticity, and is impermeable to cells and waste. It occupies
an important role in the shape and transparency of the eye.
The retina is a layer made up of several layers of neural tissue that covers the two
the posterior thirds of the eyeball. Its thickness increases towards the inner part, so
slim down again in the central fovea. The retina is responsible for collecting the
light and its transformation into nerve energy, through which it will be transmitted
information to the brain. The importance of the retina deserves that we describe it with a
greater detail.
A curious feature is that the light sensory receptors are embedded in the
retinal wall, so that the light, after crossing the vitreous humor, has to
to traverse the columns of nerve cells that culminate in the receptors. There are two
types of receptors: the rods and the cones, named so for their shapes
respective. The first are sensitive only to shades of gray and have a
light sensitivity 500 times higher than that of the cones, while the latter are
sensitive to color. This difference is due to the photosensitive pigments they have.
each one of them. There are some
120 million rods in a single human eye and they are distributed throughout the retina.
exception of the fovea and the blind spot. The cones are about 6 million and are concentrated
in the central area of the retina. In the fovea, there are only cones and with a density of
150,000 per square mm. The area where the cones reach the highest density has
a size of one ten-thousandth of a millimeter, which provides a field of view of
one third of a degree. This area, with about 2,000 cones, is the one with the highest capacity
discrimination. Note that the mosaic of visual sensation reception gives us a
resolution capability far superior to that of, for example, any television, although,
In contrast to these devices, the resolution is very high in the center and decreases.
strongly on the periphery. It can be said that it is seen with the whole retina, but it is looked at with
the macula.
The cones and rods are just the beginning of the nerve tissue in the retina,
immediately after them there are four other types of nerve cells that collect
vertically the information of the receivers and the vertical transmission and
horizontally. It can be stated that the initial phases of processing of the
Visual information is processed already in the retina itself, not for nothing its embryological origin.
it is in the brain tissue. On the other hand, those 126 million receptors send only
800,000 nerve fibers to the brain, which implies that the information from a number
important receptors, and already with some elaboration, is evacuated by the axon of a
single neuron. However, the number of receptors per fiber is not constant,
decreasing significantly in the case of the foveal cones.
All those axons we have referred to come together to form the nerve.
optical, whose mouth lacks receptors and therefore vision, so that it
it is called blind spot or optical disc.
The optic nerve penetrates the brain and in a place called the optic chiasm part of its
Decussating fibers, that is, they direct towards the cerebral hemisphere opposite to their position.
from the origin eye. More specifically: the optical fibers coming from the middle
the temporal of each retina are unilateral, while those corresponding to the half
Nasal fibers completely cross to the optic tract on the opposite side. The fibers
corresponding to the macula are evenly distributed towards one hemisphere and the other. The
axons from the retina end in the lateral geniculate bodies of the
thalamus that acts as a relay station and there a new neuron sends its axon
towards the occipital striated cortex, where along with the calcarine sulcus are the areas
cerebral areas responsible for processing visual information. From the striated cortex
branches extend towards the pre-striatal cortex (located somewhat further forward),
where visual information processing also takes place. The presence of
these branches and the coexistence of other sensory pathways in the bodies
geniculated suggest an integration of visual information with that from
other senses. Figure 2.1 presents a diagram of the visual sensory pathways.
There are some issues regarding the final disposal of optical fibers in the
brain in which it is worth stopping. Half of the scene that each observes
the eye is represented in each cerebral hemisphere, positioned upside down and, moreover, the
the terminations corresponding to the fovea occupy a disproportionately large space
large in relation to those aimed at analyzing peripheral vision. On the other hand,
this arrangement of fibers in the striated cortex is repeated again in different areas
of the pre-striatal cortex. It seems as if these different representations of the
the same scene had the function of analyzing different aspects of it such as the vision
of color, the three-dimensional or the one of movement. Finally, it should be noted that
there is another area of the cortex, called the visual association area, that is likely dedicated
to the integration of all the information processed by the other parts that we just
to refer to us.

3.2 Visual perception

The process of visual perception consists of transforming physical light energy into
internal representations of objects and shapes situated in space. How this is
possible is the goal of a whole collaborative effort among a set of
disciplines, among which we can highlight psychology, neuroscience or the
artificial intelligence. Our approach to a comprehensive explanation of the current state of
knowledge in this area far exceeds the objectives of this work. We are leaving
to limit it, then, to give a description as straightforward as possible of how light energy
ends in a mental representation. For this, we will follow the path that the
visual information travels through the structures we just referred to. The
light rays reflected by objects reach the surface of the cornea following a
almost parallel path for distant objects, and increasingly oblique as we move away
approaching the object. There they begin to curve as they pass through the different structures
ocular lenses to ultimately converge in the normal eye on the retina. Although the
The crystalline is not the only structure responsible for refraction, but it does have the power.
sufficient to, through the modification of its curvature, partially alter the
refraction of rays. In this way, it is possible to adjust the eye to the vision of objects.
near or far. Figure 2.3 shows the different indices of refraction of each one
of the structures of the eye.

FIGURE 2.3. Journey of light through the ocular structures to the focus in the
retina of a normal eye. The numbers refer to the refractive indices of each
structure in relation to that of air. (Ward, 1986, p. 42)
If for any reason the refractive indices of these structures are altered, we
we can find that the focal point of the image is not on the retina, with which
that visual acuity will be affected when an image appears on the retina
or less blurred. If the focus is located behind the retina, we talk about hyperopia or
Hypermetropic eye that affects near vision, while distant vision is slightly affected.
affected. If, on the contrary, the focus is in front of the retina, we are talking about myopia
which fundamentally affects distance vision. When the external structures do not
they have a uniform curvature so that their refractive power is not equal in
we talked about all points regarding astigmatism. Finally, if the lens does not have a good
Accommodation power refers to presbyopia or tired vision. The use of glasses.
correctors allow to alleviate or ease these problems.
When light energy reaches the retina, a chemical change occurs in the
substances that make up the retinal pigments. This chemical change alters the
behavior of the receptor cells and produces a pattern of actions
electrochemical processes inside it and in its relation to adjacent cells. From this
way the energy in the form of light is converted into nervous energy (ultimately
(electrochemistry term). These patterns of cellular activity form the basis of the
transmission of sensory information from one neuron to another and of processing
this information that neural networks produce; is akin to the 'bits' and the
"bytes" inside a computer. The retina, therefore, is a true interface between the
light and the nervous system.
These activity patterns have different characteristics depending on the type of
receptor and the particular characteristics of the light energy that reaches them.
All receptors are excited in the presence of light, but their thresholds of
excitement, The time it takes to return to the resting activity rate, and the
the wavelength of light to which they respond can be different. This leads to
that there are receptors that perceive only in shades of gray (rods), while
another type of receptors (the cones) only react to gradations of light situated within
of a certain range of wavelengths of the light spectrum; specifically,
gradations of blue, red, and green. To a large extent, the different capacity of
the response presented by these different types of cells is due to the visual pigments
what they have.
But until now we have only referred to one type of transduction processes.
from energy to another by the visual receptors (cones and rods), but what
What do the other types of nerve cells in the retina do? The answer is that they
they dedicate themselves to making calculations. Meanwhile, the receivers have received certain
color gradation, the cells of the following retinal layers compare the levels of
excitation of the nearby receptors establishing edges and profiles, they detect
movement or are sensitive to changes in brightness. In short, in the retina
produce a treatment of visual information, so that the optic nerve does not
it is limited to transmitting the activity downloads of the cones or rods, but rather they
impulses contained refer to some properties of the stimulation that
reaches the eye.
Higher up we have referred to how they are distributed in the cerebral cortex
terminals of the optical radiations coming from the lateral geniculate nuclei.
Now we will refer to the brain structures that receive nerve impulses.
and the function they perform. Recent research, among which stand out the
conducted by David Hubel and Torsten Wiesel, suggest that the striated cortex is
divided into processing units called hypercolumns, each one
of which is responsible for the analysis of the information coming from one part
from the retina called hypercolumn. Each hypercolumn occupies between 0.5 and 1 mm.
square and about 3 or 4 mm deep, that is to say the entire thickness of the visual cortex, and
contains about a quarter of a million cells. Each hypercolumn is in turn
vertically formed by a set of columns. The examination of its structure
horizontal reveals the presence of layers of different types of cells. Each
hypercolumn analyzes a hyperfield of the retina, although the hyperfields of the
Adjacent hypercolumns overlap partially. As can be assumed at this point,
the receptive fields corresponding to central vision are smaller than the
dedicated to peripheral vision with which the information analysis stimulates it
This area is more meticulous.
The hypercolumn is a complex processing machine. Inside it there is
myriads of cells dedicated to exclusively analyzing different parts of the image,
but to understand its operation we must return to the columns that it
component. Each column is formed by lines of cells, each of which
responds to a specific characteristic of stimulating information, although all the
cells from the same column are prepared to share the analysis of the same
type of information. That is, within the hypercolumn there is a division of labor
among the different columns that make it up, and a later specialization of the
cells that make up the different layers of the columns. The result is that
we have very specific cells that fire only in response to certain
characteristics and within each hypercolumn many spikes are 'produced at the same time'
time. Some cells are activated by edges, others by angles, still others by
openings, etc. The situation becomes complicated if we look at how it is processed
chromatic information, the movement or the stereoscopic information resulting from the
binocular vision. On the other hand, it is important to consider that in the nervous system the
Cells not only have an excitatory activity but also an inhibitory one. Without going into
In more detail, it could be said that the hypercolumn performs a complicated number of
computations that ultimately produce a neural behavior pattern for each
visual representation. Ultimately, the visual sense is rather a complicated
information analysis system that could almost be considered as a set of
senses.
So far we have referred, albeit in a very summary way, to how and where
One type of information becomes another type of information. But, how is it that
Under certain stimulation, do we recognize an object or a symbol? How?
a certain pattern of brain activity produced by rays of light becomes
conceptualized as the photo of a person we know or as a phrase that
Are we capable of understanding it by reading it? In some way, the brain representation (or
the phenomenal image that appears in consciousness) has to be related to
a prior knowledge stored somewhere in our brain (or in our
mind). As Frisby (1979) points out, a theory of perceptual recognition must, at
less, first explain how abstract symbolic descriptions are constructed
based on the images that can be perceived, then how can such be stored
descriptions, and finally, how one of those descriptions can be chosen and
compare it with an image that appears in the system,
occupying in this last thing only a fraction of a second. As can be assumed
this is a difficult problem and we still do not have a theory that allows us to explain
this process in its entirety. However, the current state of the research does let us
allows for some progress on the path to the solution. This is what we refer to below.
It seems that the visual system is capable of extracting particular features from a
a certain image and from it build something like a "primitive sketch"
that would capture the structure of the object's image. This primitive sketch is the unit
about which the visual experience works. In some way, this outline would include a
description of characteristics, components, location, etc.; something like a
description of the object in a unifying symbol. The outline could be constructed both at
starting from units made up of lines, textures, or colors, or by
combinations of them; that is, characteristics detectable by the visual system.
This means that the recognition process involves not only the presence of a
sensory imagery but also requires other processes of knowledge:
memory, spatial knowledge, reasoning, etc. Ultimately, perception is
a process that depends on both sensory data and prior knowledge,
That is to say, it depends on a bottom-up and top-down processing. How much
whether of one thing or another is the subject of broad debate. In any case, it is
It is undeniable that in order to understand what an object presented before our eyes is, we need
very often from the launch of hypotheses about what its nature is. This can
to make eye movements in a certain direction, to explore with greater
care of the object, to pay attention to some of its characteristics and thus reach
understand what it is about. Ultimately, there is both a guided recognition
predominantly by sensory data as a guided recognition
conceptual mind.

4. Common diseases of the visual system and their functional repercussions

Once we have seen some characteristics of the visual system, let's move on to
refer to how some of the most common damages occur in the system components or
in their mode of operation they can affect vision. Inspired by Goldstein
We can classify visual problems into four types:.
Problems focusing on the retina. They may be due to the eye being
too short or too long, or to deformities in the lenses (cornea or
crystalline). We have already referred to the alterations that this causes (myopia,
hyperopia, astigmatism, or presbyopia) and how they can be corrected through the use of
of glasses.
Blur of light upon entering the eye. It may be due to conditions in the cornea.
in the lens or in the structures prior to the retina. let's focus on the cornea first
place.
The cornea is well defended against external aggressions by its outer layer, but
any injury in this makes it a breeding ground for various types of infections,
whether viral, bacterial, caused by herpes or fungi. These lesions or infections
ulcerations can occur first and then scars that in case of being
graves can affect visual acuity. The images appear blurred and
the lights surrounded by a halo. Other alterations may have a genetic origin or be
product of degenerations associated with age. In general, corneal lesions
they are called keratitis and, as has already been pointed out, they can lead to
blindness. Treatment in extreme cases may include corneal transplant.
The typical alteration of the lens is cataracts. These consist of a loss of its
transparency that results in a decrease in visual acuity and can end up
in total opacity and the resulting blindness. The most common type of cataract in the
the population is senile cataract, a very common alteration due to degeneration of the
clear with the passage of age. Other types are congenital or traumatic cataracts,
special importance in the case of children. The only possible treatment for cases of
It would be visual impairment that is surgical.
The vitreous humor can also be a source of some eye problems. For various reasons
causes (infections, traumatic injuries, retinal lesions, etc.) may appear
inside floating bodies that appear like flies, spiders, spider webs, etc.
the vision. This type of alterations rarely significantly affect the
vision. Sometimes, these floating bodies are accompanied by visions of
sudden flashes and the presence of blood in the vitreous. In such cases, the lesion of
Vitreous can be accompanied by retinal detachment.
Retina problems. First of all, it is worth noting that retinal tissue is tissue
nervous and, therefore, is very sensitive to changes in blood flow. Good
part of the retinal injuries are related to alterations in the blood flow caused by
very different causes. One of the most well-known diseases is retinopathy
diabetic, which, as its name suggests, has its origin in the suffering of
diabetes. It consists of damage and occlusion of the blood vessels of the retina with
possibility of hemorrhages and exudates that may affect the vitreous humor. In
In a later phase, new vascularization occurs on the posterior face of the vitreous;
if new bleeding occurs, vision is affected, just as if it occurs
injury to the retinal cells. One of the greatest dangers of proliferation of
exudates between the vitreous and the retina may lead to a detachment of
this last one.
Retinopathy of prematurity or retrolental fibroplasia is also related to the
retinal detachment. This disorder occurs mainly in premature children
subjected to excessive concentrations of oxygen in the incubator. The
excess oxygen causes spasms in the retinal vessels, exudates and
neovascularization towards the vitreous. Later, often, a
retinal detachment. This is an irreversible condition unless
discover at the beginning of its development. If useful vision is preserved, it is common
strabismus and myopia.
Retinitis pigmentosa is a genetic dystrophy of the retinal receptors.
A slow degeneration of the rods occurs with loss of night vision and
from the peripheral visual field, leading to shotgun vision and reaching
to affect the macula much later. These retinal disorders are often
they appear with deafness, mental retardation, and other disorders.
Retinal detachment, as we have seen, is often a consequence
from other disorders, although it can also originate from a trauma.
It is produced as a result of vitreous traction and the separation of the surface.
external to the retina of its pigment epithelium due to the presence of exudates. The person
affected sees part of her vision occluded or has the sensation of a curtain covering part
of their vision. The treatment is surgical and, if it is quick and the affected area is not very
Extensive extrafoveal vision can be recovered. If the fovea has been detached from its
Irrigation for a long period may result in irreversible vision loss in this area.
There are some specific problems with the macula, the most well-known of which is the
age-related macular degeneration, which can result in atrophy of the
macula or in a detachment of this area of the retina. It is an important cause of
blindness in the adult and elderly population, as it incapacitates vision
central, which, for example, prevents visual reading.
Finally, within this quick review of retinal disorders, we will refer to
color blindness. This is a confusing term, as most of those affected
they maintain normal visual acuity. The problem usually lies in their perception
of colors. We have already said that color vision depends on the activity of three
types of cones. Well, there are people who due to a genetic alteration do not have
one, two or of the three types of cones. In this last case, only
sticks, so this disorder is often accompanied by photophobia, nystagmus and
disorders of visual acuity.
- Problems of the nervous structures. They are problems related to injuries that
they affect the transmission of nerve impulses to the brain. We will describe them in
its journey from the optical disc to the cortex.
Let's start with optic nerve disorders. One of the most important causes of
blindness is glaucoma. It is a set of diseases of origin
generally genetic that have in common an increase in intraocular pressure of
aqueous humor. This increase in pressure causes the globe to stretch, which ends up
causing a deformity that affects the retina and the fibers of the optic nerve. Although
its final result is a neurological injury, its origin lies in an excess of humor
aqueous due to a blockage of the Schlemm canal. There are several types of glaucoma:
we will refer only to the most common. Acute glaucoma is an increase
quickly from the pressure that causes severe pain and can affect very quickly the
vision. Open-angle glaucoma is insidious and progresses very slowly, not
noticing the subject until the visual deterioration has progressed a lot. Another type of
glaucoma is the childhood (trabeculodysgenesis 'buphthalmos') that can be congenital or
congenital. Glaucomas can also occur as secondary processes to other
ailments. This disease can be alleviated through the use of drugs or by means of
surgical. The damage to the nervous system is irreversible. In their early
moments glaucoma causes loss of peripheral vision, with
what the patient does not realize about the situation until the loss of field of vision
it is already very important and irreversible. If the disease progresses, the loss of vision is
total.
Optic neuritis is a generic term for inflammations, degenerations
the demyelination of the optic nerve. The loss of vision is the main symptom.
although this, depending on the type and severity of the disease that causes it, may reach
to recover. Among the diseases that can cause optic neuritis are
multiple sclerosis, neurosyphilis, saccharine diabetes, and even deficiencies
Vitamin supplements. One system to locate lesions is the visual field examination.
Lesions that occur before the optic chiasm are generally unilateral.
(affect a a)
only the eye). Lesions posterior to the chiasm result in homonymous alterations.
contralateral (affect the same part of the visual field of each eye), while the
lesions located at the chiasm generally cause bitemporal defects. In general,
it can be said that the more similar the defects are in the two visual fields,
the lesion is located in a more posterior region. Also, the more posterior it is
lesion, it is more likely that the macular damage is minimal and, therefore, is preserved
visual acuity.
- Other problems. Here we will refer to different visual disorders related
fundamentally with eye movement and some alterations derived from it.
When we referred to the anatomy of the eye earlier, we talked about the existence of
some extraocular muscles whose function is to move each eyeball to
to direct the gaze. These muscles are innervated by different bundles of nerves.
Injuries to these nerves, or in the brain areas from which they originate, can lead to
to affect functional vision. We will refer to some of these disorders.
continuation.
Nystagmus is characterized by the presence of involuntary, repetitive movements.
oscillatory and rhythmic of one or both eyes, in some or all positions of
the gaze. Its complete mechanism is not known and it can almost never be specified
where is the location responsible for the defect. It is currently known that some
Structures of the inner ear related to the sense of balance exert influence
about gaze fixation; in case of malfunction of these structures it can
nystagmus may appear. In any case, there are different varieties of nystagmus, so
we will refer only to some of its most striking general characteristics.
This disorder can lead to a decrease in visual acuity due to
inability to fix the gaze, illusory movements of objects (oscillopsia), or
vertigo. It is not uncommon for a person to make head movements towards
positions that allow for better fixation of the gaze. In some conditions
stimuli can temporarily induce nystagmus movements in subjects
normal.
Strabismus is another disorder related to ocular motility as well.
this is a case of an inability to simultaneously align the gaze of both eyes
about the object being examined. It is therefore a misalignment defect of an eye
whose magnitude is measured by the angle of the deviated eye. This deviation can
introduce yourself in any possible alignment.
It is important to note that the image captured by each eye is always different; this
disparity, far from being a problem, is what produces the sense of depth, since
that the two images merge allowing for three-dimensional vision precisely at
through the calculation of the difference between the images provided by each retina. In the case
from strabismus, binocular vision is abnormal, as the images presented by each
they are excessively discordant. This produces some subjective phenomena.
important factors that last until the age of seven or eight, the moment when the
the brain adapts to this anomalous situation. Diplopia consists of the same object
it appears in two different spatial positions, we would say it appears double. This is
explainable since the object appears in the fovea of one eye and in the periphery of the other.
Another phenomenon is that of suppression, which consists of the image of the eye that looks being
becomes predominant over that of the other, whose images are not perceived.
in the event that the vision is systematically fixed through one eye, resulting in
systematically suppressing the vision of the other, the latter will lose visual acuity; it is
say, it will become an amblyopic eye. This amblyopia will not occur if the fixation of
the gaze alternates between one eye and the other. The treatment of strabismus
it is aimed, on one hand, at preventing amblyopia, and, on the other hand, and closely related to
that, to achieve that the images presented by the two retinas match. The techniques
used is occlusion (covering the dominant eye so that vision is achieved with
the deviated eye), or optical devices (glasses or prisms), pharmacological drugs, or
surgical treatments.
Amblyopia has already been partially treated. It is, as we have already pointed out, a
decrease in visual acuity without any organic disorder and that is not
correctable through the use of lenses. This disorder occurs in cases where it
degrades the quality of the image that an eye offers, something that can happen when there is
strabismus or anisometropia (unequal refraction in both eyes, for example, one being myopic
and another hyperopic).

5. Vision Evaluation

5.1. Who performs the vision assessment?

The visual system, as we have seen, is a highly complex apparatus that offers
extremely important information for the subject's contact with their environment.
Therefore, it is advisable to prevent visual disorders through check-ups.
periodic ophthalmological examinations. In any case, it is essential to attend
immediately to the specialist when there is the slightest suspicion of any alteration
of visual capacity.
There are three professions directly related to eye care, although with
clearly defined functions: ophthalmologists, optometrists, and opticians. The
The functions described below may vary depending on the arrangement.
legal of each state.
An ophthalmologist is a doctor with specialized postgraduate training in the
diagnosis and treatment of eye problems of any kind, including the
prescription of corrective lenses. An optometrist is a specialist in the examination
ocular
and in the prescription and fitting of lenses, he is not a doctor and in most of the
countries are not authorized to prescribe medication. If during the examination
If the eye observes any eye disease, it must refer the patient to the ophthalmologist.
Finally, the optician is a professional trained to make corrective lenses.
Focusing now on the repercussions that vision disorders can have
regarding education, we would like to make some suggestions in this regard. It is
It is important that the teacher has an ophthalmological report on efficiency.
visual aspect of students with some significant vision impairment, as this
base will be able to decide to adapt the materials it deems necessary, use the aids
techniques that are relevant and, where appropriate, develop the development programs and
utilizations of the functional vision that are indicated. Sometimes, the psychologist
or the education professional, can use visual perception tests designed
with the purpose of making an initial detection of visual problems, to discover
problems that specifically affect classroom activity, or help the development of
visual rehabilitation programs. Later we will focus on these aspects.

5.2. The eye examination

An adequate vision assessment requires a systematic eye examination.

relatively complex where very varied aspects are taken into account some of
which we will briefly describe below.
The first step is the preparation of a medical history in which data is collected from
very diverse types but that can be revealing for the proper guidance of
post-examination, for the diagnosis and subsequent treatment. Issues such as the
age, occupation, diseases that are suffered from, or the previous evolution of vision
subjective, are relevant here. Other aspects of interest, prior to the eye exam
specifically, it is the information about eye pain or discomfort, diplopia or
vertigo, as well as the possible presence of changes in the appearance of the eyes, in the
tear secretion or the possible presence of exudates.
The measure of visual acuity is the most familiar part of the eye exam.
It consists of the subject recognizing letters of different sizes presented from a distance.
with each eye separately. The test is repeated experimenting with different lenses
corrective lenses to test if this improves the subject's visual acuity. There are systems
standardized methods that allow for the quantification of visual acuity. In the next
We will look at the sections in more detail. In cases of significant changes
of the transparency of the cornea, of the lens and when considering the
possibility of a transplant or cataract surgery can be estimated by means
sophisticated what is the potential sharpness of the affected eye.
The evaluation of refraction is a complementary examination to the previous one.
It fundamentally consists of an exploration of how light reaches the retina.
through the pupil, with and without corrective lenses.
The external eye examination explores the pupillary reaction, eye movements, the
alignment of the eyes and the condition of the ocular tissues. The slit lamp allows
explore the state of the cornea and the lens, their refractive power and the possible
alterations that may affect refraction or obstruct vision.
Perimetry estimates the state of the visual fields for each of the eyes. The
visual field is measured in degrees of arc and is not affected by distance. A
A rudimentary method to explore it is to move an object through different areas of the field.
visual; if necessary, sophisticated devices can be used through which
lights are presented inside a hollow sphere of which the subject must
inform. In this way, a map of the visual field of each can be constructed.
eye that can be very revealing for the diagnosis of functional vision
to indicate the evolution of different diseases. In the next section
We will also insist on some aspects of the field measurement.
Tonometría is a test to estimate intraocular pressure and, therefore, it is done
essential for cases of glaucoma. In these cases, the
gonioscopy to measure the angle of the anterior chamber.
The vision of colors can be estimated using sheets.
polychromatic, in which figures appear that will only be perceived if color vision is
correct.
Ophthalmoscopy is the method for examining the retina. The observation of color and the
The aspect of this structure, as well as its vascularization, is of great importance.
diagnostic.
As we have indicated above, this brief review is by no means exhaustive, as
Alongside the most common types of exams that we have gathered here, there are others.
many tests that may be indicated in specific cases.

5.3. The measure of vision

There are different ways to expose what the degree of visual efficiency of a
person. The purpose of this section is to try to present it in the clearest way possible
the different most common measuring systems and their meaning:
The first aspect we will refer to is visual acuity. This is usually
establish using the so-called Snellen chart (see figure 2.4) which is very
familiar to anyone who has ever undergone an eye exam. There are two
VERSIONES DE ESTA CARTA, UNA QUE UTILIZA LETRAS MAYÚSCULAS, Y OTRA QUE UTILIZA UN SÍMBOLO
similar to an E or a U in various positions, whose use is restricted to subjects
illiterate people or children for whom there is no certainty that they know the denomination
Regarding the letters; in the case of children under 3 or 4 years old, one must be very cautious.
to interpret the results obtained with the Snellen chart.
To each row of letters of the letter we just referred to, there corresponds
a certain numerical expression in the form of a fraction, called the Snellen formula
and whose meaning we explain below. The numerator refers to the distance to the
that the letter regarding the accommodation of the subject to be examined is presented, while the
denominator refers to the size of the symbol that is presented. This formula may
it can also be interpreted as the ratio between the distance at which the patient can
identify the symbol and the distance at which a normal eye does so. There are also
letters that measure near visual acuity, either through the Snellen formula, or
well through a numerical scale called the Jaeger scale which uses as material
lines of text with different size types. These numerical estimates often
introducing oneself using the Anglo-Saxon units of measure or those of the metric system
decimal; sometimes they are also expressed as percentages of visual loss. The table
2.9 presents the equivalence between these different measurement systems.

FIGURE 2.4. Snellen chart for assessing visual acuity, (Goldstein, p.

167)

TABLE 2.9.- Standardized measures of visual acuity

Standard measurement system of the American Medical Association.
(Adapted from Ward, 1986 and Vaughan and Asbury, 1986)

To determine a person's visual acuity, it must be done for each eye.

separated. To calculate the percentage of visual loss, an average is usually taken among the
distant vision and near vision. In any case, it is advisable to know the visual acuity
of each eye with and without corrective lenses.
The legal definition of blindness rests on visual acuity. In Spain
to be able to affiliate with the O.N.C.E. one must have a visual loss of 80%.
better eyes and with correction. In the case of the U.S., visual acuity must be
worse than 6/60 (20/200) under the same conditions.
In any case, legal blindness does not imply that the person suffering from it is completely
blind to vision. Below this threshold, other systems are sometimes used
in terms of being able to count fingers at 3 meters (approximately equivalent to
3/60), counting fingers at 1 meter (1/60); and even below that in decreasing order
of visual efficiency, perceiving the movement of hands, locating lights in
different quadrants, and the perception but not location of light. Below this level
we can talk about absolute blindness.

FIGURE 2.5. The visual field and its measurement. (Vaughan and Asbury, p. 378)

In any case, and as we now know, visual acuity is so

only one of the parameters, although certainly the most important, that allows us
evaluate visual deficiency. We must remember that visual acuity informs us as well
only from the foveal vision and is not sensitive to other types of disorders of great importance
functional. We now refer to them.

The estimation of the visual field is also of great importance, as even a good
foveal vision ensures visual reading, a serious alteration of the field that implies
Loss of peripheral vision can affect the subject's mobility. A system
a crude way to measure vision is to place a white object of 3 mm at about 30 cm from
each eye of the subject in each of the eight meridians shown in figure 2.5
under good lighting conditions. A more accurate estimate requires making a
perimetry by a specialist. A complete field represents a function of
100% in this parameter.
The third parameter to consider for the normalized measure of vision is motility.
ocular estimated through the report that the subject makes of the diplopia they observe in
its binocular field. The estimation is made through the so-called tangent screen.
located 1 meter away and using as a stimulus a light situated at the meridians
from the field at different angular distances from the fixation line of the gaze. If the
Diplopia appears within the central 20°, it is referred to a loss of efficiency.
visual of an eye, since, generally this situation makes it necessary to occlude one of
they. The estimation of the loss percentages for other orientations requires the
use of a field diagram.
The numerical estimation of the visual efficiency of an eye is calculated by multiplying
the efficiency percentages in each of the three parameters we just
to indicate (sharpness, field, and mobility). The visual efficiency of both eyes is calculated
multiplying by three the estimate for the better eye, multiplying by one the one for the worse,
adding both and dividing the result by four. In this way, a person with a
a blind eye and another normal one would have a binocular visual efficiency of 75%.
5.4. The visual report
The importance of proper education for parents and educators has already been pointed out.
knowledge of a child's visual efficiency to adjust the educational treatment that
this must be received. A good method to systematize this knowledge is to have
an updated annual visual report that includes, at least, the data below
are detailed:
Identification of the subject, age, sex, address, school data.
Visual clinical history and related aspects.
Normalized visual efficiency measures as described in the section
previous.
Causas de la deficiencia visual. Diagnóstico, condiciones antecedentes, estado
current and etiology.
Prognosis and treatment recommendations, including lenses, conditions of
lighting for work, support materials, etc.

Examiner and exam date

There are standardized models of visual reports. A good example is the
recommended by the "National Society to Prevent Blindness" of the USA that appears
collected in Ward (1986). In any case, it is worth remembering that it can be useful
including supplementary reports on aspects more specifically related to the
education. Remember that the function of vision is the perception of the environment and that
As we pointed out before, perceptual processes include both the reception of
information coming from the environment, such as the identification and categorization of it
information. Therefore, an adequate visual efficiency report for its use
psychological or educational cannot be exhausted with the mere recourse to data
sensory aspects, but it also needs to include psychological aspects, that is, of the
cognitive use of visual information gathered from the environment. The
Teacher's Manual of Mira y Piensa (ONCE,
1986) gathers some suggestions that may be useful in this regard.

5.5. Instruments for the evaluation of visual perception

Earlier we referred to the existence in the market of some tests of

visual perception that may be of interest to the psychologist or the professional of the
education as a complement to the above-described professional report, or even as
a preliminary step for screening individuals with ocular problems. We will refer to
some of them of very different nature that can serve as examples.
The Stycar Vision Tests (Sheridan, 1976) are designed to measure sharpness and
the visual field of children from birth to the beginning of school age (6-7
years). It is a relatively easy test to administer although the interpretation of the
results obtained with younger children are difficult. In any case the
the manual is sufficiently clear on this matter.
The Visual Functioning Assessment Tool (Costello, Pinkney, and Scheffers, 1980) is a
instrument of a very different nature. It was designed as a test to evaluate the
visual functioning of the student of any age in the educational environment.
It consists of 16 scales that cover very basic aspects, such as the dominance of a
eye regarding another or the pupillary or blinking reflection, up to visuomotor coordination,
mobility, knowledge of the environment, types of necessary aids, etc., going through the
standard data on sharpness, field and mobility. Thus, it is a very
complete and practical for school use and includes aspects of psychological interest
as they are relatively complex issues of visual perception.
See and Think is a set of materials for evaluation and training of the
vision that in Spain has been published by the O.N.C.E. "based on the original British 'Look and
Think prepared by the Royal National Institute for the Blind. It is organized in a
set of areas to evaluate fundamentally related to the functional vision,
so that the emphasis is not placed on numerical data or medical information,
but in the effective use that the child can make of their visual efficiency. As examples
we can cite discrimination of objects 'three-dimensional, of photos, of drawings, etc;
visomotor coordination, gesture perception, or color differentiation. Along with
this functional vision assessment presents a set of programs and
materials for the development of functional vision.

6. The utilization of visual remnants

6.1. The functional vision

We have just referred to visual efficiency as something that can be increased.

based on specific instruction programs. However, this is an idea
relatively recent, since until the 1960s, when Barraga (1964) demonstrated the
effectiveness of these programs, the notion prevailed that the use of residual vision
It could produce fatigue that, in turn, would result in a decrease in the remnants.
visual. Today this idea has definitely been banished and the trend is to treat
to make the most of the useful vision from the above-mentioned notion that the
visual perception is a psychological phenomenon that has as a necessary condition, but
not enough, having a sensory device capable of gathering information
bright. Certainly, it does not seem that any training program can surpass
the sensory limitations, what does seem to happen is that it is possible to train the subject
for a better utilization of the optical information it receives.
This is the reason why specialists in functional vision point out that the
the visual efficiency of a specific subject cannot be measured or predicted in a way
adjusted through standardized clinical procedures (Barraga, 1983). Com
(1986) points out that functional vision refers to the ability to use vision to
to perform specific tasks and that these may present very high levels of difficulty
different for subjects with similar clinical measurements.
Com (1983) has proposed a three-dimensional model to refer to the various factors.
necessary for visual function (figure 2.6). In any case, for efficiency to exist
It is necessary for a certain minimum volume to be reached to maintain a certain
comfort the use of vision. Therefore, as a preliminary step for the design of
instructional programs for the utilization of visual remnants is made
I need an adequate assessment of the subject's state. Instruments such as those collected.
in the previous section, or as those suggested by Com (1986) may be suitable for
this purpose.
The same author (Com, 1986) distinguishes three instructional approaches to be used.
based on the prior assessment that we present below in a formal way
summarized. Visual stimulation programs are indicated for individuals who have
a minimal vision or that does not make use of their residual vision in their behavior
habitual. There are people who may have some vision but who have never learned to
conceptually interpret what they are seeing. As Smith and Cote (1982) say, "the
the brain area responsible for vision will remain undeveloped unless it is
provide stimulation and visual experiences. The degree of efficiency of vision
the child's functioning is a direct result of the quality of the sequential presentation of
visual stimulation experiences. For visually impaired children, vision is not
an automatically learned process" (p. 11; cited by Corn, 1986). This type
programs may include issues such as learning to distinguish whether the light is
turned on or off, following a moving object, reaching objects, etc.
Training programs in visual efficiency would be the next step in
the sequence of visual instruction and refers to more properly perceptual aspects.

FIGURE 2.6. Com's (1983) model of visual functioning.

Among the skills to be acquired would be learning to distinguish patterns of stimuli

visuals, differentiate general characteristics and details of objects and transfer this
learning to two-dimensional presentations and symbols.
The instruction in the use of vision represents a shift in emphasis regarding
the types of previous programs, as it refers to issues such as the modification of
environment, the use of both optical and non-optical aids, as well as techniques
for maximum utilization of vision.
Coro (1986) also makes some important considerations regarding the use of the
vision both throughout the instruction process and for full utilization
about their possibilities and their subsequent everyday use. This author points out that it is necessary to have
consider aspects such as the fatigue that can occur when designing programs
to experiment with the subject when performing tasks in a perceptual modality that to the
Initially, it may seem less efficient than the one you are more accustomed to.
or, on the contrary, that it comes to overestimate its visual capabilities by abandoning
non-visual action modes are more effective. On the other hand, we must not forget
social aspects such as the tendency of the subject to avoid external help or to
use assistive devices for fear of being considered deficient and in this way their
behavior becomes less effective. In any case, the function of these programs of
the instruction is to help the subject with vision impairment to make the most of
visual cues of the environment that can even go unnoticed by people with
a normal vision.

6.2. Technical instruments to aid vision

Technical development has facilitated the development of specially designed devices

to increase the quality of the visual information inputs of the receiving subject. These
Aid does not cure the deficit, but it can help the affected person achieve more.
efficiency and independence.
Following Coro (1986), we can distinguish between optical aids, those that improve
the retinal image, fundamentally through the use of lenses; and non-optical aids,
what are those that produce environmental changes (color, lighting, contrast,
spatial relationships and time.
The type of technical assistance to be used is logically related to the type of condition.
That the subject has. If it is a field problem, the use of prisms or lenses that
increase the field (for example, a telescope used in reverse) can help to
to alleviate the problem. If the problem is the lack of visual acuity or the presence of
scotomas (blind spots in the retina), the strategy to follow will be to increase the size of
the retinal image, something that can be achieved by three methods: getting closer
to the object, increasing its size (e.g. larger letters), or using a
magnifying lens. This last system is the one that
they use a good part of the existing technical aids, which can be handheld magnifiers or
with support, glasses, or handheld telescopes. Other assistive systems use circuits
television closures that enlarge the images appearing on screen, and even,
computers that allow manipulation of the size of the representation they offer
monitor.
The manipulation of environmental conditions does not refer to the use of devices
that they expand or improve the retinal image, but rather it is intended to modify the
conditions for receiving the stimulus and, on occasions, to change the characteristics of
own stimulus so that it can be perceived better through sight. Again
we find that the type and severity of the impact are determinants for the
adjustment of this type of aids. By way of example, it is enough to consider the ways such
different lighting treatment methods that should be followed in the case of photophobia or
simple decrease in visual acuity. Issues such as the position of the subject in front of the
stimulation, the presence of reflections, the use of certain colors, the complexity of
stimulus or the time it takes for the subject to explore the presentation offered to them
they are all aspects to consider both for the educational situation and for the
own training in their visual perception skills and, of course, also
in evaluation situations.
Ultimately, the instrumental aids aim to make the most of the
potentialities of the subject's visual apparatus, and for this it may be necessary to improve by
Part of it, both the characteristics of the stimulus and the quality with which the information
stimulus reaches the subject. But at the same time, it must be taken into account that the subject himself
the subject has to learn to take advantage of all the sensory cues it receives and, still
More, one must know how to improve the conditions in which one receives environmental information.
using "tricks" on how to position oneself in front of the stimulus, how to take advantage of the
lighting and avoiding reflections, how to produce the best contrast, how long it should last
dedicate to a visual exploration, etc.
In any case, training in perceptual skills and technical aids for
employing with the visually impaired is not limited to the visual field that we have just
expose. The other sensory systems must be utilized to the fullest, and even
in a very specific way in certain particular situations. The following chapters
they will continue to address these topics in each specific area.
Chapter 3
PERCEPTION WITHOUT VISION

FLORENTINO BLANCO

It seems clear that although the analysis of blindness is not exhausted by the analysis of the
perceptual problems, these problems determine the configuration
particular cognitive of the visually impaired. Indeed, it is not necessary for the reader
he strives too much to take on the enormous importance of the visual system
in most situations that shape your everyday life and the decisive
impact of losing sight on one's way of knowing the world. The visual system
human is the result of a long phylogenetic evolution that has turned him into the
the best spatial frequency analyzer we have. Almost all our
Judgments about the environment are based, under normal conditions, on the visual system; even
a large part of our knowledge about the world and about ourselves is given to us
it presents phenomenologically in the form of 'visual images'. Therefore, to be blind
it does not only imply the impossibility of accessing certain types of energy (see the
Chapter 2) if not, what surely is
more decisive, the impossibility of representing the world "as if" we saw it. The
Repercussions of visual deficits affect purely adaptive issues in the
what has been referred to as 'life skills' and the ability to
access to cultural information through the usual mediums (literacy,
two-dimensional images, etc.). For this reason, the visually impaired must optimize the
intact sensory systems. In this sense, culture has designed instruments for
mediation (or rather, re-mediation) that allows access to relevant information about
through such systems. Therefore, we believe it is appropriate to include a chapter on
non-visual perception in a book that addresses the cognitive consequences of
visual deficit and some of the strategies we can implement to contribute to
the adaptation of the blind to their environment.
Our purpose is to explain how sensory systems work that the
blind people have at their disposal and how they use such systems. The possibility of
Answering the first question is fundamentally limited by difficulties.
methodological, technical or ethical approaches to access these systems. The second question
skirt steak
at least, theoretical and methodological problems.
On one hand, there is no theory of perception that allows us to account for it in a way
satisfactory and consistent with the available data. In this sense, it is advisable that
let us recognize before entering into the subject the difficulties that arise when we try
distinguish the concept of perception from other more or less related concepts such as the
sensation, representation or comprehension. It is generally assumed that the processes
perceptives end with the construction by the subject of a "percept"; the
Differences among theorists arise when attributing qualities to that percept.
A significant group of theories assumes that perceptual processes conclude when
the subject develops a model of the essentially neutral object, untainted by the
contents or the expectations of the system and usable by it for various purposes.
In this way, perception constitutes a process with its own rules of
functioning and that, therefore, can be studied with relative independence
regarding other processes (Marr, 1989).
A second group of theorists advocates for a broader idea of perception than the
previous, according to which perceptual processes and their result, the percept, are
always determined by the expectations of the system or the subject's previous experience.
This second group of theories admits more or less explicitly that the act
perceptive culminates in the phenomenological experience and, for this reason, is objectively
very complex, if not impossible, to distinguish perceptual processes from processes
superior such as representation or understanding. As the reader will understand, it is not
The task of this writing is to mediate in the dispute, but it is indeed convenient to point out our
current situation regarding the problem. Although neither of the two orientations has
shown greater explanatory capacity in scientific practice, it seems clear that
to propose a definition of
the excessively broad perceptual introduces a certain semantic confusion and, in
consequence, a certain methodological disorder. It is common to find, for example,
works on perceptual issues that use classical memory tasks
discrimination tasks in the absence of one of the items, object identification
relatives, etc.). On the other hand, the excess of confidence that from the beginning of the
For 60, it has been deposited in the 'expectations of the system', and not only from the point of
view of the so-called Cognitive Psychology of Information Processing, we
has faced, in the best of cases, a model of a subject that struggles between tyranny
of stimuli and the tyranny of accumulated experience, and in which perception
It constitutes one of the fronts where this agony is expressed most clearly.
It seems necessary to introduce a certain dose of common sense in this field.
We will handle a relatively restricted definition of the perceptual.
we will avoid, as much as possible, the reference to phenomena, experimental situations or
cognitive processes that will be better understood in the theoretical context of others
chapters. For example, some authors relatively often use the notion of
"perception of space" (e.g., Warren, 1978). From our point of view, the
the problem of spatiality in the blind can probably be better understood if
The mechanisms for accessing information are taken into account, but their analysis is not.
Agota does not solve this problem in any case. It is likely that we can establish
with some rigor the type of strategies that a blind person employs to perceive a
brick or a wall, but it is unlikely to allow us such analysis to affirm something about the
process by which one comes to have an idea about the city in which one lives.
The main methodological difficulty has to do with the importance of the variables.
of the subject in the field of visual impairment. On one hand, and almost without the fear of exaggeration,
we could say that each visually impaired person presents, from a psychological point of view,
a different perceptual problem. In this sense, it should be noted that the percentage of
blind people who see absolutely nothing is so rare that it seems audacious to propose.
explain the ways in which the blind access information based on these cases.
In addition, the available visual remains somewhat determine the level of involvement.
functional of other systems in the perceptual act. The previous visual experience
it also significantly influences the way functions are organized
perceptions in visually impaired individuals.
As a consequence, aside from all these problems, the subject we are talking about in
this chapter is a rather idealized subject, a subject that is not functionally used
no type of visual information and that rests its possibility of access
to material objects in other perceptual systems. Evidently, the fact that
the inability to use visual information does not imply a structural alteration of the
other sensory systems. We are talking about the famous hypothesis of the
"overcompensation". Most of the studies that have attempted to compare
Perceptual thresholds (non-visual) in blind and sighted individuals have not found differences.
substantial. In any case, the differences that appear in some situations of
Concrete tests can be easily explained by taking into account the greater
familiarity of the blind with the materials used (for example, stimuli
relief punctuation marks similar to braille characters) or the influence of the
attention.
Regarding the structure of the chapter, we have chosen to organize the information in
I return to the perceptual systems with greater functional relevance for the deficient.
visuals (somatosensory, vestibular, and auditory), dedicating less space to the
perceptual systems whose organization and functionality do not exhibit characteristics
special
in this type of subjects (taste and smell). In no case do we intend for these last ones
systems play a secondary role in access to information. What is suggested is
that are about systems that do not reorganize substantially as a result of the
absence of vision. In each of the systems we will begin by describing the
receptors, the pathways and the nervous centers assigned to processing of the
information that they capture, both at the anatomical and physiological level (figures 3.1 and 3.2
they show the anatomical and physiological principles common to the sensory systems; the
Figure 3.3 shows the primary cortical areas of the different senses.
we will review the most important research on how the
blind people use such systems to access objects in their environment.

FIGURE 3.1. A stimulus from the environment causes the receptor to generate a
electrical signal. The signal moves to the end of the nerve fiber of the receptor.
The cell body of the following neuron receives the signal from the nerve fiber of the receptor.
and generates another electrical signal, which is transmitted along the nerve fiber of
this neuron. (Goldstein, 1988, p.33

FIGURE 3.2. Sensor system prototype. The electrical signal originating from the receptor
it is transmitted to the brain along a series of neurons. (Goldstein, 1988, p.
33. Reproduced with permission from the publisher Debate)

FIGURE 3.3. Human brain showing the location of the primary areas of
cortical reception of the different senses. (Goldstein, 1988, p. 34. Reproduced with
permission from the Debate publishing house

Due to its relevance for the blind and its relative anatomical simplicity, we will address first the
somatosensory system. Here we will distinguish between somesthesia -which encompasses the
sensory submodalities that are collected basically at the skin level and perform
a fundamental role in the perception of the environment - and proprioception - that encompasses the
muscle and joint sense - which, in addition to contributing to knowledge
of the weight and shapes of objects, provide information regarding the position of the
body, both in cases of immobility and in those of movement. We will comment on it.
subsequently data related to tactile perception, texture, patterns
two-dimensional and three-dimensional patterns. The role of perception of
movement in the representation of space will be analyzed in the chapter
corresponding. In reality, and as the reader can imagine, when a blind person perceives
objects from your environment in your daily life integrates information from both.
submodalities. Therefore, and
although from an anatomical-physiological point of view it is necessary to distinguish between the
homeostatic and proprioceptive system, the organization of the most psychological part of
the chapter takes place based on the properties of the object to be perceived.
The second sensory system addressed is the vestibular system, which contributes to
awareness of body position and the formulation of reflex responses
intended for the conservation and recovery of balance. The literature on
vestibular perception is scarce and, in the case of blind subjects, nonexistent, but their
importance for ambulation determines its treatment in this book.
The auditory system, which is described below, has anatomical similarities.
with the vestibular derived from their common origin and it is precisely to their role in the
localization of sound sources and obstacles in space, functions for which
it was originally developed, to which we will dedicate more space. We will conclude the review
of the sensory systems with the description of the gustatory and olfactory systems, and the
chapter with some reflections on the experience of a world without sight

1. Somatosensory system.

1.1. Anatomy and physiology of touch: the somatosensory system

The somatosensory system receives and processes mechanical and thermal stimuli.
chemicals that affect the skin and the mechanics that are generated inside us
body. The breadth of the reception area and the variety of events or
situations that are recorded in it are reflected in the expression 'sensitivity'
general of the body" which refers globally to the sensory modalities that
understand.
A first classification distinguishes between somesthesia and proprioception. Within the
first includes touch, sensation triggered by contact of the skin with a
mechanical agent; the pressure, which implies the most intense application of a stimulus
mechanical and the temporal deformation of the underlying tissue; the pain, sensation that
derives from tissue damage caused by a mechanical, chemical, or thermal agent; and
temperature, obviously triggered by thermal agents. The tingling, and the itch
Tickling is also usually included within somesthesia. Additionally, one must take into account
count some of the signals collected in the viscera, which are often not
perceived and used in the regulation of vital functions.
The term "proprioception" was introduced by Sherrington at the beginning of the century to
design the set of sensations triggered from the locomotor system. It encompasses
the position of the joints, the speed of movement of the limbs and the
degree of muscle contraction, information that is also not usually made conscious
although it is very useful for the structures responsible for controlling movement.
In addition, the proprioceptive system cooperates with the somesthetic in detection.
of the shape and weight of the objects being handled. In fact, skin anesthesia
the hands do not prevent the recognition of the shapes of objects. On the other hand,
signals collected at the skin level, for example from the soles of the feet, contribute to the
knowledge of the body's position and displacement.
Somesthetic stimuli are collected at the ends of the extensions.
receptors of sensory neurons whose neuronal bodies are in ganglia
close to the brainstem or the spinal cord to where they are conducted by their
transmitting extensions. These are terminations -either bare or surrounded by a
capsule of neurons whose axon diameter and myelin sheath are very variable.
These two factors: axon thickness and myelin influence the conduction velocity of
impulses in neurons. The wider axons with a greater amount of myelin, which
it becomes an insulating cover, they offer less resistance to the flow of current -or
electric signals - in the nerve fibers. Additionally, myelin, being arranged to
segments on the axon, causes the current to flow only at the points where it
interrupts in a jumpy manner. Therefore, the larger the diameter and the quantity
With myelin, the conduction of nerve signals is faster.
The somesthetic receptors are located between the layers of the skin at superficial levels.
the deep ones (see figure 3.4.). It is necessary to distinguish between those of hairless skin (the ones of the
palms of the hands and feet, and the inner skin of the arms) and skin with hair.
The area of skin assigned to each receptor constitutes its receptive field. The more
the receptors per unit area, the smaller the field of each one and also smaller
the distance required for two simultaneously stimulated points to be perceived
as distinct. Thus, at the tip of the fingers, this distance is about 2 nm; in the
arm, about 30 rnm, and on the back, about 70 rnm.
The simplest type of receptor that exists is the free nerve ending, which
it branches out and distributes to different levels of the skin. The degree of specificity of these
receptors vary greatly from those that exhibit a certain preference for some
submodalities to those that are absolutely polymodal.

FIGURE 3.4. Somatosensory receptors of the hairy skin of man. The

free nerve endings and Merkel discs end at a more superficial level
than the other endings; the Pacinian corpuscles are the structures most
deep.

Encapsulated endings constitute another large group of receptors. A capsule

it is a covering of connective tissue that is located at the ends of the fibers
nervous. The most well-known are the Meissner corpuscles, which are located
exclusively on hairless skin, more densely on the fingers of the hands, and the
Pacinian corpuscles, Merkel discs, and Ruffini endings, which are
they are distributed in both skin types (see figure 3.5, where their
properties). Specific to hairy skin are the receptors that are coiled.
at the base of the hair follicles that detect hair movement and its rate of
speed, or the friction of objects moving over these hairs and their speed of
displacement.

FIGURE 3.5. Properties of the mechanoreceptors related to touch in the

human hand. The left column shows the size of the receptive fields.
The central column represents the type of skin receptor. The right column
indicate the brand of the stimulus and the electrophysiological response. Each row shows the
Characteristics of a type of tactile units. (A) Type Q fibers of rapid adaptation
(AR I). (B) Fibras tipo 1 de adaptación lenta (AL I). (C) Fibras tipo 2 de rápida
adaptation (AR II). (D). Type 2 fibers of slow adaptation (AL II). (Adapted from
Valbo and Johansson, 1984). (Rosenzweig and Leiman, 1989, p. 272)
Each of these terminals has characteristics that make them suitable for recording
certain features of stimuli. Thus, those of Meissner detect changes in the
stimulating condition as they stop responding to a stimulus that does not change. This trait,
tied to their location in the fingertips, has led to the assumption that they are the
detectors that contribute the most to active touch, which involves exploring objects
through its manipulation, a point that has been experimentally verified by recording
electrically the activity of various receptors during it. More changes
rapid stimuli are detected thanks to Pacinian corpuscles, but their spatial resolution is
smaller. The Ruffini and Merkel receptors register sustained deformations of the skin, the
first from large areas and the second from small areas. A stimulus is needed
less intense to provoke a response in the receptors of the fingers.
than in other areas of the skin, and a single discharge from the nerve is enough to perceive
the stimulus. Furthermore, the transmission through those fibers is faster, not only because of their
thickness and myelin, but also by a more direct access to the centers where
it culminates the process of perception. It seems, then, that there are, within somesthesia,
paths that enable fast and accurate processing. Others, on the other hand, are slower and
diffuse, they contribute to maintaining a flow of information where it matters less the
urgency and the location that the signaling of the presence of the stimulus.
the receptors mentioned so far are also found in the ligaments
muscles, joints, and in the walls of the viscera, such as those of Pacini, Ruffini and
free nerve endings.
The target of the sensory nerve fibers is the spinal cord or the brainstem.
according to the situation of the receiving area. There are two main somesthetic pathways.
the more voluminous and new in phylogenesis is called the dorsal column pathway,
because it is part of the dorsal (posterior) region of the spinal cord. The axons, thick and
Highly myelinated, correspond to the transmitting prolongation of neurons
sensory that have their "neuronal body in a ganglion and do not connect in the
spinal cord more than through collateral branches. The pathway of the dorsal columns reaches
to the medulla oblongata, where it relays in the Goll and Burdach nuclei, first
station of this route. The middle bundle of the lemniscus originates there, which is decussated allied
opposite and incorporates fibers that transmit sensitivity from the head, which reach to
ventrobasal complex of the thalamus, where they are distributed topographically according to the site
from which the signals originate. Neurons are projected from it to various areas of the
cortex, mainly from the parietal lobe. By virtue of the decussation, the cortex
The right somatosensory is "informed" of signals triggered on the left side.
from the body, and vice versa. Through this pathway, signals related to 'fine' touch are transmitted
discriminative, and vibration, which implies the repetitive stimulation of the skin, or,
in everyday circumstances, the successive stimulation of the receptors as
skin runs over an object (see figure 3.6).

FIGURE 3.6. Ascending tracts of the somatosensory system. a) The system

spinothalamic. The two areas of the somatosensory cortex have maps
different somatotopic areas of the body, but both receive thalamic afferents. b) The
lemniscal system, which goes through the dorsal columns of the spinal cord, and the dorsal fasciculus
lateral. The fibers of the dorsal column are added from the medial side to the lateral side,
as they ascend through the medulla; the gracilis fasciculus, more medial, begins in the part
inferior of the medulla; the cuneate fasciculus, more lateral, is added closer to the brain.
(Bridgeman, 1988, p. 137)

In the anterolateral area of the spinal cord are located the spinothalamic tracts.
constituted by fibers of spinal neurons, which receive signals from the propineurons
sensitive. These contacts are verified orderly in various areas of the part
posterior of the spinal cord, from which the fibers cross to the opposite side and ascend to
thalamic nuclei of the posterior ventral group and other neural groups of this
structure, nuclei that are involved in attention processes and in the 'awakening'
diffuse of the cerebral cortex or that constitute convergence points of signals
visual and auditory. From the thalamus, fibers project to the somatosensory cortex.
The submodalities conveyed by this beam are tingling, stinging, temperature, and
pain both sharp, intense, localized and acute, as well as dull, diffuse and continuous. In the
spinothalamic tracts, the quantity, the diameter and the degree of myelination of the
axons are smaller than in the previous pathway, the transmission, therefore, is slower, and the
the spatial resolution is lower; although it should be specified that there are differences
regarding these characteristics, to the extent that a distinction is made between way
neospinothalamic, faster and more direct, and paleospinothalamic, slower and with a number
of the upper synapse. Acute pain, for example, is transmitted through the pathway
neospinothalamic and the deaf or diffuse, by the paleospinothalamic.
A certain number of fibers from this last bundle head towards regulatory centers of the environment.
internal -vegetative centers-, where they initiate unconscious responses that
they correct or attenuate the state captured by the receptors and modulate the propagation of the
signals (see figure 3.7). The pain relief centers of the brainstem constitute another of
the white matter of the paleospinothalamic tract and the origin of fibers that descend to the
spinal cord where they attenuate the intensity of the messages that are sent until the
areas where perception takes place. In the perception of pain, it seems to be involved.
the thalamus and not only the cerebral cortex as in the rest of the sensory systems, it
that may be due to the high biological value of this signal. Another peculiar aspect of the
transmission of pain is the involvement of various cortical areas in the different
aspects of their perception. There is data that supports the dissociation between perception and
the emotional experience of pain, of which the results of the
extirpation of a region of limbic cortex in patients suffering from chronic pain,
in which the emotional symptoms resulting from pain disappeared - anguish,
depression-, however, maintaining the objective perception
from pain.

FIGURE 3.7. Analgesia system of the brainstem and spinal cord showing
the inhibition of painful signals that reach the spinal level. (Guyton, 1989, p. 223).

The use of signals for various functions and in different centers is not
exclusive to the paleospinothalamic tract. Actually, at each relay point, the
information that rises is processed and put at the service either of reflex behaviors that
they are carried out unconsciously without the intervention of higher structures, such as that of
to remove the hand from a flame or a sharp object, or to bend the fingers to
to hold an object that makes contact with the skin, response that newborns exhibit
born and disappears in the first months. In addition, the various seasons of
relief and the cortex can also enhance or attenuate messages, and not just harmful ones,
which allows us to affirm that the central nervous system contributes to 'shaping' the
signals coming from the periphery. On the other hand, both paths (of the lemniscate and
spinothalamic pathways) can influence the level of attention with which signals are processed.
through branches that abandon the main bundles and activate the centers of attention
in the brainstem.
As for proprioception, the receptors are located, as has already been
commented, in the muscles, tendons, joints, and ligaments. Among the fibers
striated muscles, which possess numerous contractile proteins that enable such
function, the fusiform fibers are found, so called because of their spindle shape,
rounded in their central area and thin at the ends or elongated, in which the
the number of contractile proteins is scarce. Two types of fibers reach them.
sensory: some very thick and myelinated, that coil and make up the
anulo-spiral endings, and other thinner ones, secondary endings, which only
they contact with the elongated spindles. This set made up of a muscle fiber
modified and a nerve fiber constitutes the detection team of the elongation or
shortening of the muscle when it relaxes or contracts. What happens is that any
change in length of the
muscle, from those caused by the force of gravity to those provoked by
orders from the motor centers of the nervous system affect the spindles, and,
consequently, in the nerve fibers that are arranged over it. Thus, the change is
captured and transmitted at full speed, so these centers receive it promptly
information about the consequences of the action and the state of the muscle, and they can
correct it. Something similar happens with the tendon receptors, called organs.
Golgi tendon organs, highly sensitive to active muscle contraction, that
it involves a change of tension regarding the bone where it is inserted.
It has already been mentioned that some of the somesthetic receptors behave like
proprioceptors. Pacini and Ruffini constitute a system designed to register
the position of the joints, detecting the acceleration in the first
displacement of the joint and the angles in which they remain. In the
ligaments have tension receptors similar to those of tendons, and endings
simple nerves, similar to those that detect pain.
These proprioceptive neurons enter the spinal cord or brainstem, where
they leave branches that transmit the detected signals to neurons that organize responses
reflexes, automatic, intended to adjust muscle tone or release the tendon from a
overloading. The main extensions make contact with the second ones.
neurons of the pathway in spinal segments located at a higher level than
They entered. The fate of these neurons, which constitute the spinocerebellar tracts and
they are part of the lateral white matter of the spinal cord, it is multiple. If they transmit
signals coming from the lower extremities mainly go to the cerebellum,
although a group of them goes towards a mysterious core, called Z, from which they depart
fibers that are incorporated into the middle lemniscus and follow their trajectory to the cortex
Cerebral. The spinal neurons that transmit signals from the extremities
superiors reach the relay nodes of the spinal column pathway, and from there,
they follow the identical path that this one does, also forming part of the lemniscate way.
In both cases, the cortical areas that receive the most thalamic projections are the
motor cortex located in the frontal lobe and part of the somatosensory cortex
immediately adjacent, from the parietal lobe. This different destination of the signals of
the lower and upper limbs reflect, possibly, the different functions of
those that survive. The lower limbs come into play for the maintenance of
the posture both in situations of immobility and during movements. The
the cerebellum is a center for coordinating balance and muscle tone and must integrate
this information regarding the position of the head, neck, etc., for
perform such functions effectively. The upper limbs are
involved in other functions, basically of intervention or active exploration in the
exterior, in which feature extraction and fine control of movements of the
hands require the intervention of the somatosensory and motor cortices. This organizes
the action based on information from the body itself, of its position in space, of the
objects to manipulate and movement memories that it obtains from very structured
various, both cortical and subcortical, as well as from the receptors.
The perception of the shape, texture, weight, and temperature of objects involves, as
it has pointed out, to the somatosensory cortex, which includes about five distinct areas.
along the parietal lobe and extends towards what is known as the motor cortex, in the
frontal lobe. Each of the regions of somatosensory cortex receives messages
captured by all kinds of receivers and coming from the entire receiving area, although
seems to exhibit a certain specialization for some feature of the stimuli. All
they present a more or less extensive topographical organization of the body, modules
vertical-columnar-associated with the location and identification of the stimulus, and
horizontal modules, apparently involved in aspects such as the duration of
stimulus.
Other areas located at the back of the parietal lobe, known as cortex
association parietal, must carry out an integration of what has been processed in the areas
previous ones, since neurons respond actively no longer so much when a
stimulus affects a very specific point on the skin, but rather when a stimulus travels through the
palm of the hand or the forearm. Neurons have been identified in them that remain
you activate the time interval that elapses from when a monkey manipulates a
object until it pairs it with another identical one. The maintenance of the activity has been
interpreted as the physiological correlate of the retention of traits of the test object
in order to decide whether it is the same or different from what is proposed as a model (Koch and Fuster, 1989).
These areas of the parietal cortex also seem to be involved with the
movement of the hands during manipulation and with the movements of the eyes.
about an object of interest (in fact they are connected to the visual cortex). It is all
What these later areas have been associated with is not so much concrete aspects of a
behavior regarding "natural" behaviors. Their participation in actions such as the
Described seems to also be indicated by its connections with some of the areas
visual and with motor areas involved in planning, initiation, maintenance and
execution of intentional movements. Ultimately, the information collected by
the proprioceptors of the hands, arms, and shoulders and of the texture receptors of
the fingers of the hands, for whose processing parietal areas seem to be responsible
previous ones, is essential for adjusting manipulative movements. The
the posterior parietal cortex would fulfill, in this sense, a fundamental function in the
definition of the characteristics of extrapersonal space, whose specific traits
would be analyzed in anterior parietal areas. In these areas, feature extraction
is put at the service of the global construction of the object. However, the areas
the posterior parietals could be considered sensory only to the extent that they
they are responsible for analyzing sensory information, although this information seems to be put
in the service of intentional processes for access to information through a
direct motor intervention in the extrapersonal space (Butter, 1980; Hyvarinen, 1980,
Sakata, 1980).

1.2. The concept of tactile perception: Theoretical problems

Although intuitively we all know what we mean when we talk about

tactile perception, things are not so clear when we delve minimally into
this concept. In fact, it is really complex to find suitable labels for
the type of phenomena we are going to analyze in this section.
First of all, a problem of theoretical biases: it is generally identified that the
the phrase 'tactile perception' with psychophysical or peripheralist types of work on the
touch, that is, with experimental situations with little "psychological sense" and
ecological. On the other hand, if this label does not convince us, we have the option of
resort to the well-used and most publicized "haptic perception."
In fact, each of these expressions refers to two theoretical conceptions and
two opposing work philosophies, which we pointed out in the introduction, each one of
which has its advantages and disadvantages. Of course, the greatest
part of the situations. that we are interested in here in relation to the perceptual world of the
the blind are closer to the haptic than to the psychophysical, but there are some
relevant situations that we could not integrate into the first category. Moreover, if the
The idea of touch as a haptic system entails a special emphasis on the control of the subject.
Regarding the flow of information, there would be real problems in deciding what
we consider as control. In general, in the Gibsonian tradition, there is a tendency to take
as a control criterion the subject's activity, their exploratory movements
manual. Let's consider, for example, the difficulties that arise in deciding whether a
Braille reading system in which the subject keeps a finger motionless on a drum
rotating with embossed characters implies an active or passive process on the part of the
subject. However, and especially when we do not know the object we are trying to
to perceive, is it the subject who controls the flow of information or is it the object, the set of
its physical attributes, the instance that "programs" the activity of the subject, or are both
things at once? It seems that the solution to this problem lies in the reflection on a
previous epistemological problem on which, surely, the very
the psychology of blindness has much to say. We will try in this section to analyze
some aspects of this problem.
The debate between these two perceptual models has a strong component
phenomenological that is already found in the works of Gibson himself (1966) and one of his
more
clear predecessors regarding their holistic and active conception of the system
tactile. We refer to D. Katz, especially in his famous Tastwelt (1925). Indeed,
both authors highlighted the idea that every perceptual experience has two poles: a
an objective pole and a subjective pole. Some perceptual systems enhance more the
objectivity than others. In this sense, the visual system is the most focused on the
exterior, the most tyrannized by the world, and the proprioceptive system the most linked to the
states of our organism. The issue, as one can see, has many twists and turns in the
that we are not going to delve into now, and that we will address later.
It is worth noting, on the other hand, that some of the most refined theoretical models and
current promising involve a highly modularized conception of the
tactile perception that goes beyond traditional psychophysical models. Let's think,
for example, in the models designed based on Fourier analysis that have so many followers
they have won in the study of visual perception and have begun to be applied to
study of tactile perception (Loomis, 1981; Loomis and Lederman, 1986). Of any
way, an important objection to this type of approach has to do with recognizing their
little relevance outside of the laboratory situations from which they are generated.
It will take, in the best case, some time for these models to start
generate transformations in our notion of psychological subject and, therefore,
start projecting in predictions and relevant decisions in the context of the
psychology of blindness.

1.3. The perception of texture

The term 'texture' refers to most of the physical properties of the object, such as
the surface roughness, hardness, elasticity, or viscosity, excluding the
temperature and the general shape. On the other hand, although we apparently should
to contemplate the perception of texture as a special case of haptic perception or
active, various studies have shown that the movement of the hands does not contribute
useful information in the perception of an object's texture, although it must indeed
there is a relative movement between it and the subject's hand. For example,
Lederman (1981, 1983) and Lamb (1983) asked their subjects to estimate the roughness
of a series of surfaces under two different experimental conditions: in one of them
the subject moved their finger across a static surface, while on the other
subject kept the finger static while the surface moved beneath it. The
results of these works indicate that there are no differences in the fit of the
roughness estimates between both experimental conditions. Thus, no
we can consider in the strict sense that the movement of the hands constitutes a
key factor in the perception of roughness and, therefore, the
The perception of roughness should not be understood as a case of haptic perception.
No
however, in everyday life, and given that most objects do not move, the
The subject must move their hands if they want to obtain information about the texture of an object.
What are, then, the variables that determine the perception of roughness?
Let's start by noting that most of the work on tactile perception of the
roughness tests have been carried out with sighted subjects with their eyes covered and the few
that visually impaired individuals have focused on applied issues, such as
Braille reading or the construction of relief maps. Among these last ones, some
Researchers have found, for example, positive correlations between performance
in a braille reading task and a roughness discrimination task (e.g., Nolan
and Morris, 1960) and, although we do not have data, it is likely that this type of
the trend would remain if we correlated performance in a task of
discrimination of roughness with any other task involving deployment of
complex systematic strategies for tactile exploration.
On the other hand, some of the studies on tactile discrimination of roughness
conducted with psychics have been designed and executed by researchers
interested in the psychology of blindness and are profusely cited throughout
this book (Lederman or Taylor, for example). Finally, it is worth noting that
almost all these jobs used as material to stimulate striated surfaces in the
that systematically varied attributes such as the depth of the grooves or the
separation between them. Considering the above, we list
continuation of some of the most substantiated experimental results on
perception of roughness (Loomis and Lederman, 1986).
First of all, it seems that the most determining attribute in perception is to stimulate
Roughness is the depth of the grooves. The force applied during the exploration
The stimulus also decisively influences the perception of roughness, at least
within a certain range. Additionally, it seems that the increase in skin temperature
clearly improves the perception of roughness. On the other hand, if the depth of the
striae remains constant and the depth of the field varies (the distance between the
edges that define the groove and the surface that delimits them) does not seem to vary
substantially the feeling of roughness. It does not seem to influence too much the
presentation speed of the stimulus, regardless of what is moving
the stimulus or the hand.
References often appear in literature to the fact that with some types
The sensation of roughness increases if we introduce something between the skin and the stimulus.
a specific material, for example, a sheet of paper. The truth is that this
the phenomenon does not occur with just any type of material and, in general, it is more pronounced with
very high spatial frequencies. The phenomenon, which Katz (1925) already mentions in his book
About touch, it must be interpreted in terms of interferences between stimulation.
that comes from the movement of the finger over the surface and the stimulation that
provide the pattern to examine.
So far we have only talked about the perception of roughness and the term texture
refers, as we have already pointed out, to other properties, such as elasticity, the
hardness or viscosity. Unfortunately, these other textural properties have received
very little attention from researchers interested in the mechanisms
general aspects of tactile perception and even less by researchers interested
in the psychology of blindness.
To conclude, it is worth noting the fact that the texture of an object can be
also inferred from acoustic indices, as has been demonstrated
Lederman (1979). In fact, whenever tactile or visual information is deficient
or ambiguous to make a decision, the sounds produced when touching objects can
to be used with a certain reliability. In any case, if the subject has at the same
time of clear tactile information and acoustic indices will tend to make decisions
based on tactile information.

1.4. The perception of complex patterns

We will try to organize the content of this section based on the distinction between
bi- and three-dimensional stimulation patterns, although such a distinction is not strictly
possible. Indeed, any significant tactile pattern must necessarily be
three-dimensional. Any drawing or relief map contains information by definition
three-dimensional. In any case, this distinction captures the idea that the patterns
bidimensional are informatively, and not perceptively, restricted to the plane,
while the three-dimensional patterns are not.

The perception of two-dimensional patterns

Starting from the famous work of Gibson (1966), it is very common to find in manuals and
reviews a clear distinction between two general modes of tactile perception, touch
passive and active touch, or, generically, haptic system. As is well known, the
Gibson's work aimed to demonstrate the superiority of active touch over passive touch in
the perception of two-dimensionally distributed shapes. As stimuli, Gibson
used molds to make cookies. In the case of active touch, the subjects explored
freely the molds. In the case of passive touch, the molds rotated on the palm of
the hand of the subjects. Indeed, Gibson found that the subjects recognized
better the shapes in the first case than in the second, but left unexplained if the
the phenomenon was due to the active control of exploration, to the contribution of the
kinesthetic information or the highest perceptual resolution of the fingers in relation to
the palm of the hand.
Various authors have attempted to address the issue through partial replies to
Gibson's work (Schwartz, Perey and Azulay, 1975; Cronin, 1977; Heller, 1980).
Although there is still no absolute agreement on this matter, what seems clear is
that Gibson's work oversimplified it. To avoid any doubt, we are going to
to conclude this initial reflection on the distinction between active touch and passive touch by commenting
an ingenious experiment designed by Magee and Kennedy (1980; cited in Loomis and
Lederman, 1986). In their first experiment, they make it so that in the active touch condition
your subjects trace the outline of a drawing of a familiar object with the tip of a finger,
while in the condition of passive touch, the experimenter moved the hand
of the subject on the outline. Surprisingly, the passive group carried out the task of
recognition better than the asset. Although the interpretation of the results is not
too clear, yes
It is his opposition to the Gibsonian approach.
What advantages does active touch present, if any, and what does it give us?
they can contribute these issues about the problem of tactile perception of form in
Blind? Let's start with the second one and we will surely find some.
clues about the first. First of all, it is worth noting that there are very few
occasions when the subject passively perceives the environment through their hands.
It is likely, therefore, that other body locations are more adapted.
phylogenetically for this type of function as hands. In any case, there are
certain mechanical devices (see the chapter on reading in this same volume)
that allow the reading of Braille characters without moving the reading finger. The errors that
subjects initially commit themselves but then overcome it with practice. On the other hand, mechanisms
of substitution
visual like the Optacon or the TVSS (Tactile Visual Substitution System), regarding which
we will expand further down, allowing to collect spatial information through touch
without the need to move the hand or the area of the body that receives the vibrating stimulation.
All of this allows us to think that kinesthetic indices are not strictly
necessary in all contexts in which the perceptual process is initiated
touch; it seems rather that the movements would be at the service of the search process.
of concrete objectual attributes. There would then exist specialized movements in the
analysis of the different attributes of objects (texture, volume, shape, hardness, weight,
etc.) and whose deployment would partially depend on the level of categorization of the object to
to perceive (Lederman and Klatzky, 1987). There would also be other types of movements
which we will not analyze now. In any case, some of these movements occur in
the extent to which objects do not move. That is, in many cases it is not so
the encoding of kinesthetic indices is as important as the fact that the
Information that stimulates our receptors has a sequential nature. This type of
the approach is particularly useful for understanding how the blind perceive
three-dimensional objects, a question we will address in detail further below.
The problem of the perception of distributed information on the plane by individuals
The blind find full meaning in Braille reading, a topic that will be the subject of a chapter.
complete in this book; therefore, it will hardly receive attention in this section. In
In any case, we would like to highlight some typically occurring phenomena.
perceptive in relation to Braille reading, focusing essentially on the problem
of the readability of Braille characters.
Firstly, gathering the results of an original work by Loomis (1981a)
let's start by demystifying an old hypothesis regarding the greater readability of the
Braille characters in relation to other types of characters. Indeed, traditionally they
has stated that this supposed superiority of Braille was fundamentally due to its
punctuation nature, which hypothetically fit the physiology of certain
tactile receptors. Loomis compares the readability of Braille characters with
continuous tactile characters generated from the first ones and does not find
significant differences. In reality, although this is not the most appropriate place for
develop it, the readability of Braille characters depends on the ability to
spatio-temporal resolution of cutaneous receptors (for a review, see Loomis,
1981b).
Nevertheless, this reference to the temporal resolution of cutaneous receptors, leads us
allows for commenting on the supposed 'slowness' of the processing system
tactile. Based on a masking paradigm, Craig (1982) finds that the
the subject can report two patterns of points presented through an Optacon and
separated by a maximum interval (SOA) of 10 milliseconds. In this work, it
they only used the first 18 rows of the Optacon's vibrating matrix to form the letters
o y x, which were presented randomly in each of the trials. Before or after the
presentation of one of such letters, the complement of it was presented (the rest
from points of the matrix). The data indicated that with intervals less than 10
Milliseconds made it possible to achieve a certain resolution between the letter and its complement.
Assuming this fact, one might think that touch is not as slow as it is usually believed. The
reading speed would probably depend more on the presentation systems and
the manual macromovements involved in reading Braille. Furthermore, this idea leads us to
would allow for the acknowledgment of the increase in reading speed that occurs when
devices that display Braille characters on tapes that move to
great speed under the subject's finger, without them having to carry out the
habitual movements.
A separate comment is warranted on the work regarding the legibility of braille characters.
carried out by Nolan and Kederis (1969). These works aimed, on the one hand,
estimate the relative readability of different characters and, on the other hand, find out what
characteristics determined the greater or lesser readability of them. To do this,
they used a tactile stimulus presenter (tachistotactometer) that allowed
establish with a relative reliability the readability thresholds of such characters.
As a global result, it is found that those characters are more difficult to read.
which show more points and those that show points in the third row
from the cell.
However, the tactometer used by Nolan and Kederis had some
design problems that affected the accuracy of the results obtained (see
Foulke, 1982). To resolve these issues, a new device has been designed in the
Perceptual Alternatives Laboratory, from the University of Louisville, which presents
some advantages
About the previous version. First of all, the new device presents only one letter.
in each exhibition. Secondly, and since every point of the cell is
controlled by an independent solenoid, exposure times can be
significantly reduced compared to the device used by Nolan and Kederis, which
which allows for obtaining more reliable and accurate measures of readability. Thirdly,
allows for measuring letter identification times in a more reliable way as well
precise. In this sense, the subject is asked to loudly pronounce the name of the
this acoustic signal is picked up by a microphone that stops immediately the
chronometer activated with the presentation of the letter and makes it disappear from the surface
of exhibition.
As Foulke (1982) interprets the works of Nolan and Kederis, when
determine the minimum exposure time necessary to identify a letter, it is being
actually measuring the fraction of time necessary to activate short-term memory
I put a picture of the perceived letter. It is understood that the system should employ more
time if the subject had to carry out a categorization task, that is,
assignment of the activated record in short-term memory to the category it belongs to.
Challman (1978) uses the apparatus designed in the Perceptual Alternatives Laboratory.
to determine the time required to identify the characters whose readability
Nolan and Kederis (1969) had estimated. Challman thought that if the correlation between
both types of measures were low, the identification time could be a predictor
more suitable for reading speed than readability times, since a
registration cannot be useful until it is categorized. Indeed, one was found.
low correlation between both measures (30), but the hypothesis about the speed of
reading
it cannot be tested as the available data does not preserve the differences
individuals.
Aside from this fact, both devices apparently present a problem.
relatively serious methodological: the stimulated finger remained always static
about the presentation surface, when everything seems to indicate that the movement
The lateral aspect of the skin can be an important perceptual index in the reading process.
braille. In this sense, Kilpatrick (quoted by Foulke, 1982) uses a new
presentation device in which the finger remains static while a tape that
Braille characters move under it. The logical prediction would be that
Improving the presentation conditions, the thresholds should be lower than the
found by Nolan and Kederis, and indeed, that was the case. However, such a difference
it may not be considered important if we take into account that the subjects used by
Kilpatrick were experienced adults in Braille reading and those used by Nolan and
Kederis were children.
The following area in which the analysis of pattern perception makes sense
bidimensional in the blind is the technology of designing support graphics for
learning or wandering. Although such graphic devices are used with
considerable abundance in the education of blind children and as support for mobility,
There are very few works that attempt to systematically analyze what the
factors that would allow the optimization of their design and use (see Schiff and
FouIke, 1982). Most of the time, relief graphs are limited to
directly reproduce the graphic patterns in ink, implicitly based on.
the idea that what works for sight must also work for touch, idea
hard to admit, even from common sense. Surely the reader must have
I occurred to think about the problems that decoding would pose to a blind person.
perspective or the possibility of understanding that one object partially obscures another in the
graph.
Fortunately, there are some groups of researchers trying to overcome this.
types of prejudices based on the analysis of some of the basic processes involved in
the perception of embossed information. Special relevance is given to this context
works on the role of movement in these types of situations. This line of
The research is very well represented in the works of S. Lederman and his group.
These works assume the idea that the representations that a subject elaborates when
explore a relief device is fundamentally based on heuristics
Kinesthetic For example, the duration of an exploratory movement can allow
an estimation of the linear distance between two points; one concrete form may be
represented through indices related to the muscular activity involved in its
perceptual resolution or by the angular or goniometric indices that derive from the
joints.
The central task of their work (Lederman, KIatzky and Barber, 1985) requires the subject
follow with your finger a zigzag path between two points and estimate the distance in a straight line
straight line (Euclidean) between them. If the movement plays an important role in the
Line straight coding, the metric variations on the route should affect the
estimates of the Euclidean distance between the two points. The results indicate that, in
effect, all subjects (congenital blinds, late blinds, and sighted) used
kinesthetic heuristics to estimate the Euclidean distance between the two points. From this
way, as the route increased in length, the estimated Euclidean distance
between the starting point and the destination was increasingly overestimated
clearly. This distorting effect was more pronounced in the case of the blind
congenital in the case of late-blind and sighted individuals, which suggests that the
visual experience can contribute to the estimation of distances from the
tactile exploration. The question is how to interpret these results. As before
we pointed out, one possibility is to assume that the subjects estimate the distance to
based on the duration of finger movements. Another possibility is to
to think that the estimates are based on the distance traveled by the fingers. Although the
data does not allow to decide this issue, it is not difficult to think of a hypothetical design
that does allow it. In any case, it seems appropriate to understand both hypotheses as
strategies that can be implemented as a consequence of different
variables. For example, it is likely that the use of a spatial heuristic will result
easier for subjects with greater visual experience.
In the same direction point the works on these topics by S. Millar (1985), if
These are works that are even more focused on representational issues. It is about
analyze what the use of kinesthetic or spatial heuristics depends on, and their
research is based on a hypothesis according to which only are put into operation
kinesthetic heuristics when it is difficult to use spatial encoding strategies.
One implication of this hypothesis is that younger subjects will use more
heuristic cinematic tics, especially if the use of strategies becomes difficult.
spatial coding (for example, changing the body's orientation with respect to
relief device). The general hypothesis also predicts that blind subjects
They will use kinesthetic heuristics more frequently than spatial ones. The results.
generals do not allow maintaining the initial idea and allow thinking that the movement is
one of the most stable keys in the development of mental representations about
two-dimensional touch devices.
In any case, everything seems to indicate that this work needs to be linked to
practical situations if the aim is to offer rigorous construction criteria
and the use of relief maps. It is curious to note the enormous distance that
separates theoretical work from applied work in this field. The rigor
the experimental work we have just discussed contrasts sharply with the
use of subjective reports, surveys, appeal to experience or to: criteria
rationales on the part of researchers more interested in applied issues (for
a review, see Schiff and FouIke, 1982.
Jansson (1988) has compiled in a recent work the main problems that are
they are raised when we try to design relief graphics for the blind and, therefore, the
problems that we should address as a priority. The wide variety of techniques
currently available for creating graphic supports for the blind (plastic or
relief papers, graphics derived from video or computer devices in form
of raised dot patterns, etc.) should lead us to a certain optimism. In
In reality, relief graphs present a good number of problems: 1) as already
we have pointed out, the original of the relief graphs is usually of a visual nature; 2)
it is very difficult to obtain a global perspective of the available information in a
graph; 3) they generally contain too much information; 4) they need to incorporate
truly relevant information for touch; 5) the method that produces the graph
influence their perceptive properties; 6) they result, in any case, modes
highly arbitrary ways of representing reality, especially in the case of the blind
Congenital. Most of these problems do not have simple solutions and
they require a research effort that is yet to be made.
A special case of information perception from distributed patterns
bidimensionally it is constituted by the so-called visual substitution systems,
such as the Optacon (Optical-to-Tactile Converter) or the T.V.S.S. (Tactile Vision)
Substitution System). Both systems register information through a camera.
spatial and allow the subject to perceive it in a matrix of vibrating stems. In the
in the case of the Optacon, the subject perceives vibrations in a finger, while in the case
of the T.V.S.S. it does so on the chest or the back. The interesting thing from a point of view
The theory of this type of systems is that the subject can impose a certain control over it.
process of extracting spatial information (moving the camera in different
directions) without changing the surface of the stimulated skin. In this sense, they can
to be conceived (Loomis and Lederman, 1986) as somewhat special haptic systems.
Indeed, the works of Bach-y-Rita and his collaborators (Bach-y-Rita, 1979;
Bach-y-Rita, 1984; Epstein, Hughes and Schneider, 1986) have attempted to show that
when blind subjects control the camera for a long period of
training can lead to a loss of awareness of skin stimulation,
starting to experiment with objects in an objective phenomenological space. These
observations agree with the viewpoint of Gibson (1966) or Katz (1925), point
from the perspective according to which, let us remember, the objective pole of perceptual experience
predominates over the subjective pole when the subject
exercise active control over information access. In addition, Guarniero (1974), in
a phenomenological analysis of their training process in the use of the T.V.S.S.
he observed that when he controlled the camera he was able to distinguish between the
movements of the image produced by the camera and those produced by the
movement of the object itself, while it was not able to do so when another
the person controlled the movement of the camera. .
The analysis of the T.V.S.S. provides a good starting point for the study of what
it surely constitutes one of the central issues in the phenomenology of the
blindness, that is, the problem of what Bach-y-Rita himself calls 'attribution of
externality. The problem of attributing externality to skin stimulation and others
related problems will be addressed in some detail at the end of this chapter
in a section dedicated entirely to the phenomenology of blindness. In any
case, and to conclude this section, we must point out that there will still have to go quite
time until these types of systems become truly useful and adaptive in the
daily life of the blind.

The perception of three-dimensional patterns

Unfortunately, and as we have been pointing out in other sections, we must

to recall the radical scarcity of jobs that analyze in a systematic way the
mechanisms that blind people use to perceive three-dimensional objects.
This research shortage is all the more dramatic as designs continue to be made.
support objects for learning daily living skills or activities
school designs, without such designs being justified by stable construction criteria and
clear. Yes, as has already been made evident in the previous section, it seems important
investigate the mechanisms involved in the perception of two-dimensional patterns
distributed
due to their relevance as representational supports of spatial information, still
the analysis of the processes on which access depends should be of greater importance
to the three-dimensional objects, more basic from an adaptive point of view and that
They can play, as we will see later, an important role in the process.
educational for the visually impaired.
Generally, when we talk about the tactile perception of three-dimensional objects,
we reduce the problem to the analysis of the situations in which the movements are
exploratory of the hands that provide information about the object, forgetting
that there are other tactile modalities that allow us to access information. In
definitely, we often confuse tactile perception and what some authors with
good criterion is called 'manual stereognosis', taking the part for the whole. In this
we have been understanding by tactile perception any act of knowledge in
the information about the object implies a physical-mechanical contact with the
surface of our body. In this sense, and paraphrasing the Third Law of
Newton, we could say that the tactile perception of an object depends on the resistance.
what object opposes our intention to know it.
In any case, it seems that all the tactile modalities we deployed for
to know the objects in our environment presents as a common trait the emphasis on the
active control of the subject over the information extraction process. This statement
which apparently is very intuitive deserves some additional comments. In fact,
to radically assume that the fundamental aspect in the explanation of processes
involved in the tactile perception of objects is the subjective control it implies,
surely, taking hand movement as a criterion of activity and, ultimately
term, of active control. In reality, we are probably facing a problem of
phenomenological nature, or rather, in the face of a phenomenological problem that generates a
theoretical construction criterion. Although we will return to this argument further down,
we return to the idea that control over one's own manual activity depends on
broad sense, from the level of categorization of the object we are trying to perceive. Everything
seems to indicate that when perceptually accessing an unknown object, it is its
the physical structure itself that determines the tactile modality and the specific strategy
what we must put into play (Lederman and Klatzky, 1987).
In this section, we assume that the concept of 'manual stereognosis' may provide
correctly accounts for most of the strategies that are activated when a
a blind person tries to perceive an object through their hands. In this sense, stereognosis
manual would come to be conceived as a perceptual submodality of 'stereognosis'
"tactile", a concept that generically refers to the processes of tactile perception of
three-dimensional objects. To justify this argument, it is worth remembering that some
people are capable of actively using other parts of the body, such as the feet, the
forearms or the sensory surfaces of the oral cavity, to access
perceptively to the objects in their environment. The existence of these submodalities
alternative tactile methods should not be understood as a mere anecdote; in fact, the
The analysis of the same should provide criteria to develop intervention programs.
Furthermore, aside from the ethical implications, the situations in which a subject does not
important cognitive functions should be understood as
crucial situations to test our general models on the
human cognitive functioning.
In any case, the information we have so far seems to indicate
that the perceptual resolution capacity of these alternative submodalities is
smaller than that of other phylogenetically better-adapted submodalities to access
to environmental information. For example, Weimberg, Lyons, and Liss (1976, cited by
Loomis and Lederman, 1986) found that in a figure recognition task
three-dimensional geometric shapes the percentage of correct answers was significantly higher
when the subjects explored with their hands than when they used mechanisms of
"oral stereognosis" (99% and 74%, respectively).
Another tactile perceptual modality that has received some attention in the literature already
from Katz himself is the 'percussion'. Percussion is a fundamentally technique
used by doctors to examine the condition of some internal organs. Its
the structure is well known: the doctor places a finger on different areas of the
the patient's body surface, while tapping with another finger from the free hand on
areas of the body that are more or less distant. The perception of the vibrations reflected in
the internal organs allow for various clinical decisions. Katz showed that
some people without special training in this type of modality were capable
to appropriately discriminate the shape of some objects placed in a box
simply hitting the walls of it, and they did it well even when they didn't
they had acoustic information. In any case, we do not have it at the moment
of information about the functioning of this tactile modality for the blind.
But, without a doubt, the tactile modality that becomes more important in perception of
three-dimensional patterns is what we have called "manual stereognosis" which,
approximately, we can identify with the broadest sense of the concept of
"haptic perception." The data we currently have about the
mechanisms involved in the perception of three-dimensional patterns in blind individuals are,
unfortunately, scarce and in many cases contradictory. In general terms, it
it can be maintained that the seers are usually better than the blind in tasks of
recognition of common objects (e.g. Ayres, 1966), a trend that may perhaps be
explained in terms of familiarity with such objects, especially if we have in
count some data derived from tasks in which non-stimuli were used
relatives. For example, Davidson, Bames, and Mullen (1974; cited in Loomis and Lederman,
1986) they asked their subjects to explore a three-dimensional solid object and it
they were later identified in a comparison group of three or five objects. The
congenital blind
adults performed at the same level as the seers when the comparison group
only presented three objects and they were clearly better than the comparison group
five objects. Apparently, the exploration strategies of the blind were more
effective in isolating the distinctive features of objects, and in the more complex task
it was especially important to perceive such traits. In any case, it seems clear that
at the same level of familiarity with the objects, the exploration strategies of the
blind people are clearly more effective than sighted people and this is even more so
accused the more attentional resources the task requires. The question, then, lies in
in deciding whether this hypothetical greater effectiveness of the blind when the level of
familiarity is controlled due to a fine adjustment of the strategies of
exploration of the characteristics of objects is indeed a consequence of a
optimization of attentional resources, or it is due to the fact that they categorize better
that the seers the tactile information.
On the other hand, the observations we have recently conducted within
a research on the teaching of Physics to the blind (Sevilla, Ortega, Blanco,
Sánchez and Sánchez, in preparation, allow us to think that the blind use when
exploring unfamiliar three-dimensional objects general strategies similar to those
that the clairvoyants use. As Zinchenko and Lomov (1960) highlighted in
a classic work on the guidelines for exploring objects seems necessary
distinguish between micro and macromovements. Micromovements have the mission to
maintain the excitation of the receptors and the associated pathways. The macromovements
they are really involved in the acquisition of information about the object and
they can be divided into two categories from a functional point of view: movements
of exploration and search movements. Additionally, two phases are observed.
exploration. In the first phase, the subject explores the tactile space searching for the object of
interest. The movements during this phase are fast and continuous, which is why the use of
tactile information is minimal. During the second phase, the hands search for a 'point of
perceptually prominent anchoring in the structure of the object. In our observations
we have been able to confirm that the anchoring point is chosen based on strictly defined criteria
structural when the subject cannot assign specific meanings or functions to the
objects.
When the object begins to be known and acquires meaning, the subject can choose.
as anchoring points functionally relevant elements for understanding and
handling of the object, for example, the origin of the ordinates in a didactic device that
model a three-dimensional representation system. This phase allows to establish the
relative position of the object with respect to the body in the tactile phenomenal space.
One of the functions of search movements is to "measure" various
aspects of the object, for example, using the time spent going from
One part to another of the object, as we have pointed out that it occurred in the case of the
perception of two-dimensional patterns. However, some of our
observations allow us to think that the specific procedures that can be
activate to infer distances between points of an object or of a two-dimensional pattern
they have a lot to do with the demands of the task for which it is carried out
exploration sequence. For example, we have recently observed that the
Measurement procedures can be intentionally optimized if the task requires it:
the subject explores a model of an island with a series of objects distributed throughout
from its surface. When the subject knows that their task is to reproduce the arrangement
the origin of the objects on the island is quite common for the subject to set in motion
more reliable specific measurement strategies than pure time estimation
It takes time to cover the routes between the objects on the island, for example, such a strategy
evident as 'counting the fingers or the spans that fit between two objects'. This type of
strategies have been observed in both blind and sighted individuals, although they appear more
frequently among the first (Blanco and Colom, 1991). A characteristic trait
additional to this search phase, which occurs similarly in the case of the
vision, is that the hands do not feel the object evenly and continuously, but rather they
they stop when the fingers find critical points on the object's contour (corners,
borders).
From this approach to the problem of tactile exploration patterns of objects
three-dimensional, it does not seem unreasonable to maintain with Lederman and Klatzky (1987) the
hypothesis that the hand comprises two subsystems that are, at least
conceptually, different: a sensory subsystem, with cutaneous, thermal receptors and
kinesthetic, which we use to learn about the world of objects, and a
motor subsystem that allows us to manipulate objects. Although methodologically
we can separate manual exploratory movements from sensory inputs, in
reality involves two interdependent subsystems. This approach leads us
probably to a possible conceptual reconciliation between the notions of active touch and
passive, assuming that the different types of manual movements are the result of
the interaction between sensory inputs (physical structure of the object) and interests
of the subject.
The model by Lederman and Klatzky (1987) distinguishes, as we have been suggesting,
between "apprehension" and "recognition". Apprehension is understood as the process by which
how an observer accesses the properties of an object and assigns meaning to them in a
perceptual unit. Recognizing, as the reader might suppose, consists of accessing
perceptively to an object already apprehended and, therefore, categorized.
The unit of analysis that the model uses is the 'exploratory procedure'.
(exploratory procedure), defined as "a stereotyped pattern of movement"
some of whose properties are invariants and others very typical. In addition, it does not
presupposes a direct correspondence between an exploratory procedure and a
special hand configuration, a fixed pressure, a specific receiver or effector.
Let us think, in this sense, that the perceptual access to three-dimensional objects
It involves the evaluation of various attributes of the object, some of which, so to speak
to say it, 'they are distributed in the plane' and others depend on the overall analysis of the object. For
example, the perceptual analysis of the texture of an object or a part of it is
generally carried out from a lateral movement of the fingers in the same
plane, while the perceptual access to the global form implies the integration of
cutaneous indices that may belong to different planes in the phenomenal space.
This idea allows us to think that the tactile perception of three-dimensional objects is,
surely, the best empirical context to analyze the mechanisms involved in the
tactile perception, allowing, as we have already hinted, a conceptual integration
of active and passive touch. In fact, it seems that exploratory procedures
(elements of active touch) could be conceived as controlled procedures
by the subject (intentional, in a way) that enables access to indicators
low-level perceptive (cutaneous, articular) that run, so to speak, at a level
subpersonal. The model has been tested in successive works (Klatzky,
Lederman and Metzger, 1985; Lederman and Klatzky, 1987; 1990; Klatzky, Lederman and
Reed, 1987; 1989), but always using sighted subjects, although, undoubtedly, it can
to be of enormous usefulness in the analysis of tactile perception in the blind.

1.5. The development of skin sensitivity

A global analysis of the available data suggests that in most of the

tasks related to what is traditionally understood as skin sensitivity
(threshold tactile tasks, tasks for locating stimulated points on the skin,
, blind children often perform better or equally well compared to sighted children. Ziémtsova (cited by
Ananiev, Larmolenko, Lomov, and Veker, 1967) also found that the lower threshold
tactile discrimination in the tip of the right index finger is lower in children
blind Braille readers than sighted children. In most studies, not
evolutionary analyses are carried out, although some of them seem
indicate that the tactile sensitivity of blind children improves with age and that the
differences regarding the psychics are more noticeable among adolescents (Renshaw,
Wherry and Newling, 1930.
On the other hand, texture discrimination tasks are generally performed with the
same ability for sighted children and blind children. Moreover, this ability
it seems to improve with age, especially from 7 years old.
Despite the scarcity of work on these issues, the data allows us to think.
these perceptual functions are also subject to evolution, although not
we can clearly determine the factors that cause it. On one hand, we could
thinking about the tasks of threshold and localization of stimulated skin points
evolution can be marked by the gradual increase in density of
peripheral pressure receptors, although there is no clear data on this. There is a lack of
histological studies that allow us to establish the guidelines followed by development
anatomical of the cutaneous receptors and also lacking are functional studies on these
issues that extend to broader age ranges. One of the most significant problems
seriousness of this second option has to do with the fact that the procedures
experiments that use the studies we have been discussing are almost always based on
in the verbal reports of the subjects, whose reliability and viability at early ages
it should be called into question. In this sense, it could be feasible to use more often
experimental paradigms that have proven interesting in the study of development
visual or auditory perceptive with sighted children, for example, the procedures of
habituation, conditioning and measurement of variations in autonomic responses.
It seems, on the other hand, that the development of texture perception does not have for
What to follow a course parallel to the one followed by the functions mentioned above.
Although many authors analyze texture as a form of tactile sensitivity
(Warren, 1978) some recent work has highlighted the enormous
importance of the subject's activity in the perception of the characteristics of the
objects that we collectively refer to as texture (Lederman, 1981; 1.83). It seems, in
this sense, that the development of the perception and discrimination of textures may be
more linked than the psychophysical functions themselves to the evolution of patterns of
exploration of the objects, which should, in turn, be analyzed as expression,
surely, from general cognitive development, as we will see in the chapter
corresponding.

1.6. The development of the ability to tactile discrimination

Although the notion of discrimination is very broad, we only include the results here.
of tasks in which the subject can simultaneously access two or more items
about which it should pass judgment. Although the discrimination of braille letters
has often been used as an experimental procedure, we consider that
these types of jobs involve the implementation of categorical processes that
must be analyzed in other contexts (see section on pattern perception
bidimensional in this same chapter and chapter on reading braille.
Let's see, first of all, what happens with shape discrimination. A
Judging by the available studies, it does not seem unreasonable to think that discrimination
tactile of the form, especially when using unknown items or objects for
children, is closely related to the mastery of exploration strategies and, therefore
so, with more general aspects of cognitive development, an idea that is upheld based
two empirical arguments. On one hand, no differences have been found among blind individuals.
and seers in this type of tasks (Schwartz, 1972; Pick and Pick, 1966). On the other hand,
some authors have found high correlations between performance in tasks of
tactile discrimination, intelligence quotient (Crandell et al., 1968), mental age (Harnmill
y Crandell, 1969) and braille reading (Weiner, 1966; quoted by Warren, 1984). Lastly,
it seems that the development of the ability to discriminate shapes in blind children
it follows a non-cumulative course, showing no significant improvements since the first.
grade up to the fourth grade (Morris and Nolan, 1961).
On the contrary, the development of the ability to discriminate between different lengths
it does not seem to be as closely related to general cognitive development as discrimination of
forms (Duran and Tufenkjian, 1970). On the other hand, some authors find that the
blind children discriminate sizes and lengths with greater precision than sighted ones
(Sato and Anayama, 1973), although the tendency to overestimate these parameters increases.
with the age among blind children and not among sighted ones (Block, 1972). Lastly,
Morris and Nolan (1961) found that lengths smaller than 0.75 inches were
poorly discriminated in all age groups used (from first to twelfth)
grade).
The data regarding the development of weight discrimination is very scarce and,
some sense, contradictory, although, in general terms, we can point out that not
there is no improvement between 8 and 14 years and that blind children tend to be better
that the seers in this type of tasks (Block, 1972).
In general, we can suggest that the different discrimination tasks differ in
as to its degree of permeability regarding the general cognitive development of the child.
In this way, a sort of hierarchy or gradient of permeability can be proposed.
what part of the most basic functions, such as the perception of size, weight or
length, relatively independent of cognitive development, and which reaches up to the
more complex and indeterminate functions, such as the perception of texture, shape or
the identification of the object. There is a set of phenomena whose nature oscillates
between the perceptual and the representational. We refer to 'perceptual' illusions.
Some studies have shown that seemingly visual illusions, such as the
Müller-Lyer phenomenon also occurs through touch, independently
from visual status (Over, 1966), which is difficult to explain if one does not refer to a certain
space or
amodal or intermodal representation mechanism that operates correctly when
the task is relatively basic, like estimating the length on the plane, and that
it starts to fail when the task requires the blind subject to put into operation
mechanisms that operate in three dimensions and with parameters that are difficult to estimate.
As we will see throughout the chapter, this approach is good for the case of the
tactile perception, but requires serious modifications for its adjustment to perception
visual. At the base of these adjustment problems is the fundamental role of activity
in tactile perception (Ananiev, larmolenko, Lomov and Veker, 1967) and some others
issues that we will address when we talk about the phenomenology of perception
touch

2. The vestibular system

The vestibular system detects the position and movement of the body in space.
based on the information provided by receivers located in structures
specialized structures that are part of the inner ear. This type of information goes through the
general unnoticed, but it is essential for the mechanisms that maintain the
posture and the coordination of movements. In normal subjects, it seems to occur
a common ground between vestibular, kinesthetic, and visual information in both
Functions. The lack of sight gives the vestibular receptors a crucial role.
The inner ear consists of two parts called the bony labyrinth and the membranous labyrinth.
membranous. The bony labyrinth consists of a series of cavities located in the region
petrosa of the temporal bone, which houses within it a complex of systems of
membranes. The shapes that the labyrinths take are of three semicircular canals and
two cavities or sacs -- the utricle and the saccule -- on each side, where the
balance receptor cells, and a snail -the cochlea- where the cells are located
auditory receptors. These structures are filled with fluids: perilymph in the areas
that are bounded by hard walls and endolymph on the inside, with membranous walls
(see the top of figure 3.8).
In humans, the semicircular canals are arranged at angles of 90 degrees.
degrees and oriented horizontally (you actually have to tilt your head about 30
angles to be arranged parallel to the floor), anterior or superior and posterior.
FIGURE 3.8. Membranous labyrinth and organization of the ampullary crest and the macula.
(Modified from Goss: Gray's Anatomy of the Human Body. Philadelphia, 'Lea & Febiger,
modified by Kolmer by Buchanan: Functional neuroanatomy. Philadelphia, Lea
The upper channel connects to the posterior, which then opens.
to the utricle where the horizontal canal also drains. In the inner area of each
In the duct, there is a widening where the epithelium appears thicker that receives the
name of the ampulla, where the ampullary crest formed by the cells is located
receptors and supporting cells. The receptors are hair cells, with hairs (from 40 to 69 per
cell), of which one --the ciliary body-- located at one end, is mobile and large and, the
the stereocilia - fine and small, the farther they are from the kinocilium.
The little hairs are immersed in a gelatinous mass called a dome, which, when it
displaced pushed by the movements of the endolymph tilts the hairs and sweeps the
wall of the ampulla. When the stereocilia bend over the kinocilium, it occurs.
electrical activity in the receptor and in the opposite case, blocking. In the channels
horizontally, the cilia are oriented towards the midline of the body and, in both
remaining, outward. The receivers can
collect head turns made at increasing or decreasing speed in the three
dimensions of space, although there are other types of receptors that only collect
changes in the direction of the turns. The directional sensitivity of the receiver and,
thus, the channel is given by the position of the cinosilio. The electrical signals are
transmit from the receptors to nerve fibers arranged at the base of the
receptors.
The right superior semicircular canal falls in the same plane as the
left posterior and the anterior on the left side in the same plane as the posterior
right. In fact, the semicircular canals work in pairs: when the head
for example, from right to left, the endolymph follows the movement and pushes
the stereocilia of the left horizontal canal over the kinocilium, and those of the canal
horizontal right side in the opposite direction. Therefore, the nerve fibers that
inervan
the receptors on the left channel are excited and those on the right side are inhibited. As
these fibers transmit these signals to the brain, the vestibular centers receive
information from the transaction made by two indicators: increase in activity on one side and
decrease in the other. It is more difficult to understand the cooperation between the channels.
superior and posterior. It seems that the turn of the head forward and to the right
triggers activity in the upper right channel and causes a blockage in the posterior
left. Cooperation here is, therefore, different (see bottom of figure 3.8).
The utricle and the saccule contain gravity and linear displacement receptors.
forward, backward, upward, downward, or laterally, also performed at speed
increasing or decreasing. Its receptors, also hair cells, arranged between cells
of support, group in the macula, thickened area of the epithelium. Above the macula
utricle and beside the saccule are located two gelatinous masses, flattened in this
case, which contain calcium carbonate crystals or otoliths. When the head is
if it tilts or if a linear displacement occurs at a non-uniform speed, the endolymph
makes the gelatinous mass and the hairs of the receptors tuned to the direction
of the movement come into contact, an inclination of the bristles occurs in a
a certain direction and the electrical activity is triggered or blocked that affects
nerve fibers. In these cavities, the cilia of the receptors are oriented towards
a demarcation line called striola whose curvature allows it to cover a
vast
range of addresses to which a group of receivers is sensitive.
The nerve fibers that receive stimuli have their cell bodies in a
ganglion called Scarpa, located near the inner ear, from where
these signals are transmitted to the central nervous system. These fibers are part of the
VIII par cranial or vestibulocochlear nerve but in this case the vestibular fibers
they terminate in the vestibular nuclei, while the auditory ones do so in the
cochlear. There are four nuclei that relay vestibular information to each side of the
brainstem, each of which has specific functional traits. Thus, in
the lateral vestibular nucleus. that receives messages from the utricle, some neurons
they process signals related to tilts of the head to one side, others to the other, and
the magnitude
from your response is related to the angle of inclination size. These neurons
they are sensitive to direction. Others, on the other hand, are directly influenced by the
cerebellum, a motor center, among whose functions is to contribute to maintenance
of balance, so that messages converge in the lateral vestibular nucleus
sensory related to the position of the head and, therefore, of the body, and messages
motors, and orders are originated that determine the degree of contraction or relaxation of
the flexor musculature that will depend on the change in position detected in the utricle.
The superior and medial vestibular nuclei receive and process signals related to
head turns influence motor centers that govern movements of the
eyes, thus influencing the direction of the gaze. For example, when the head turns from
from right to left on the horizontal plane, the receptors of the right horizontal canal are
inhibit and the corresponding ones on the left side are activated. Once both signals
they reach the contralateral superior and medial vestibular nuclei, orders are sent
what determines the contraction of the muscles responsible for the right eye to
move medially, that is, to the left, and the left laterally,
also to the left, and the relaxation of the muscles that operate in the sense
opposite. Consequently, when the head turns from right to left, the eyes it
they involuntarily move from left to right and "compensate" for the change of
head position, helping to keep the plane of vision stable. From the
the same way the turn of the heads from left to right causes the eyes to
right to left, and the checked in the posterior-anterior direction, that of the eyes towards
upward, and vice versa. The control of eye movements is also influenced by another
types of signals like visual ones and those from the cerebellum, as the coordinating center of
movement, in light of the sensory information collected from different channels
sensory. These vestibular nuclei, also involuntarily, can influence
in the posture, through the contraction or relaxation of the neck muscles and of the
back, causing the head to maintain a position aligned with the rest of the
body and trying to restore bodily balance when it is threatened.
The other vestibular nucleus, the inferior, receives messages from all areas.
vestibular receptors as well as the cerebellum (see figure 3.9).
The cerebellum coordinates visual, vestibular, and muscular sense contributions.
the "awareness" of the position of the body and head. In subjects deprived of
In these last two senses, they are essential, as they trigger
corrective responses to imbalances. The help of the cane as a detecting instrument
of accidents in the field of mobility could be situated on a plane
"preventive" of such imbalances. However, visual experience allows the
elaboration
of images from the family space of enormous utility for wandering, although these
Spatial maps seem to be constructed at the expense of auditory and muscular information.
(proprioceptive or kinesthetic).

FIGURE 3.9. Connections of the vestibular nerves in the central nervous system.
(Guyton, 1988, p.257)

Finally, let's point out that vestibular signals also reach the cerebral cortex.
via the posterior ventral nucleus of the thalamus, and can thus access consciousness. The region
the cortical assigned to vestibular processing matches that of general sensitivity
from the head, in the parietal lobe, although other regions of the temporal lobe, where it
locate the auditory cortex, and the frontal lobe, specifically those that control the
Intentional eye movements seem to receive vestibular information.
Unfortunately, and despite the enormous importance of vestibular information in the
Most of the situations we address in this book, we have not found
no work in which the way is systematically analyzed in which the
The visually impaired use this type of information. In the best of cases, it is usually pointed out.
that their contribution is fundamental in the de-ambulation and in the construction of
spatial representations, but it seems necessary that this contribution be specified
beyond what common sense indicates or the extrapolation to the blind of the
data obtained with psychics.

3. The role of auditory perception

The analysis of the functions of auditory perception in blind people has received,
surely, less attention than it deserves. In addition to the functions that the
auditory perception usually has in any hearing person, in the hearing impaired
Visuals present some usage peculiarities that deserve to be taken into account.
hearing allows, for example, the visually impaired to discriminate sounds, localize, detect
and avoid obstacles, or identify people or objects. The consideration of all these
issues has allowed concrete measures to be taken in order to improve the adjustment of
blind to the middle. All of this will be addressed below. First, let's review some
basic concepts about the anatomy and physiology of the auditory system.

3.1. Anatomy and physiology of the auditory system

In humans, the auditory system is equipped for sound detection.

comprised within a wide range of frequencies, for the discrimination between sounds
of different intensity and for the localization of the sound source. It has special
relevance, as it enables spontaneous language learning and is therefore,
essential for verbal communication. For blind individuals, it becomes important
the fundamental functions for which it was originally developed: the detection of the
presence of people or objects due to increases or decreases in loudness of
the own steps when approaching or moving away from them and the determination of the
distance at which these objects are located, as if it were a sonar system.
The ear 'tells' the blind person part of what the visual system cannot offer him.
especially about that which is beyond the possibility of physical contact
direct.
Before we begin to describe the auditory system, we will briefly comment on some
of the properties of sound waves (see figure 3.10). When it is said that the
Sounds 'travel' through the air refers to the vibrations generated, for example, by
the engine of a car, when it starts, produces variations in air pressure in
sine wave shape. The crest of the waves corresponds to the compressions or
air compressions, and the sine of the waves to the decompressions or rarefactions, of
such a way that a condensation originates a rarefaction and this, in turn, a new one.
condensation, a process that repeats until the wave's extinction. Although the speed
The transmission of sound waves is constant, approximately 335.5 meters.
per second, the number of vibrations (that is, of waves) is variable: the number of
the cycles of high-frequency sounds - treble - is higher than 500 (Hertz) by
second; and that of low frequency -bass- is between 20 and 500. The
the nature of the vibrating agent, its elasticity, etc., determine this characteristic of the
sounds: the tone. The amplitude of the sounds is given by the intensity or strength of the
vibration and, in the wave, by the distance between the peaks of each condensation and
subsequent rarefaction. The unit of amplitude is the decibel, which is equivalent to the
intensity of a sound of 3000 Hz, which is minimally audible. In its travel through the
air sound waves deform when they "collide" with objects, the smaller the object, the more
its size, and lose intensity as they move away from the sound source. Tone and
Intensity determines the loudness of sounds, which should be considered a quality.
psychological. There is no direct relationship between tone and intensity regarding the
sonority, but it varies across the audible spectrum. In general, intensity
the lower and higher tones are perceived more weakly. A
constant frequency the most intense sounds are perceived as louder.
In reality, most of the sounds we perceive are composed of multiple
simple vibrations that our auditory system analyzes separately. For example,
when we hear a melody performed by an orchestra we can perceive
separately each of the instruments
even if their vibrations are generated simultaneously.

FIGURE 3.10. Definitions of sound parameters. At the top, a

a vibrating body pulls the surrounding air and pushes it alternately, creating
waves of condensation and rarefaction that disperse it from the body. Below it
three sinusoidal representations of air pressure at each distance from the
source of the vibration. The wavelength is the product of the period of vibration and the
speed of sound; a higher vibration frequency, a sound frequency.
(Bridgeman, 1988, p. 114)

FIGURE 3.11. Macroscopic anatomy of the ear. One of the reasons that explains the
restricted sensitivity of human hearing frequencies is the physical filtering of the
sound waves that occur as sound travels through the auditory canal
external between the ear and the eardrum. The cochlea and the semicircular canals (the organs
Vestibular systems are enclosed in a hard bony shell. (Bridgeman, 1988, p. 420).

Now let's describe our auditory apparatus. The ear is divided into three parts:
outer ear, middle ear, and inner ear (see figure 3.11). The outer ear includes
the auditory pavilion or ear and the auditory canal or auditory tube. The first one is
adapted by its shape to collect sound waves adequately, although in the
man has lost the ability to orient himself towards the source of sound as it happens
in other animals. The auditory canal measures about 3 cm, conducting the vibrations of the
air towards the middle and protects the eardrum with a double device:
the distancing from the exterior and the secretion of repellent wax for insects.
this duct amplifies the intensity of some sounds when
they reach the closed end of the tube and the waves that travel are reflected and reinforced
arriving. The tympanic membrane. flared, with its concavity oriented towards
downward and outward and with an area of about 6 cm2, closes the external auditory canal and
it isolates it from the middle ear.
The middle ear is a small cavity, about 2 cm3 in volume, that communicates
with the nasal passages and, through them, with the external environment via the trompa
by Eustaquio. This contact with the outside allows for the exchange of gases and prevents the
vacuum in the middle ear, so that the chain of ossicles it contains can vibrate
against the vibrations of the eardrum membrane on which the first one rests
them, the hammer. The vibrations in the hammer are successively transmitted to the
anvil, the lenticular and the stirrup, which vibrates over the membrane of the oval window, which
it limits with the inner ear. The arrangement of the membranes and the bones fulfills a
primary function: to compensate for the different resistance of vibrations in the media
aerial, in which they are initially produced, and liquid, which bathes the inner ear. The
bones act as a lever system that decreases amplitude and increases the
force of the vibrations. This same effect is obtained thanks to the difference of
the size of both membranes - the oval window membrane is about twenty-five times smaller than
the tympanic membrane - As a consequence, the vibrations are adapted to the surface
vibratory and are not lost. They are the low tones, due to their longer wavelength,
the most affected in the middle ear. In this section of the ear, two small
muscles prevent potential damage to the structures of the inner ear caused by very loud sounds
low frequency intense. The tensor of the eardrum, when it contracts, retracts this
membrane inward, and the stapedius does the same with the stirrup, so that
reduces the vibratory surface and increases the stiffness of the ossicle chain. This
the system also allows to dampen background sounds, focusing on high-frequency ones
fundamentals in verbal communication, and eliminate the interferences of the sounds of
our own voice.
The inner ear has developed from a vestibular cavity called the lagena that
has taken the form of a snail -the cochlea-. The cochlea consists of three tubes called
vestibular ramp, cochlear duct, and tympanic ramp, separated from each other by
membranes -of Reissner and basilar- and rolled two and a half turns upon themselves. The
the vestibular ramp is separated from the middle ear by the membrane of the oval window.
one end and communicates at the other end, helicotrema or apex of the snail, with the
tympanic ramp that, in turn, extends to the membrane of the round window,
small opening that leads to the temporal bone, located on a plane lower than the
oval window. Both ramps are filled with perilymph. fluid similar to others of the
existing outside the cells. The cochlear duct contains the organ of
Corti, which rests on the basilar membrane, bathed in cortilymph, a liquid of
composition similar to perilymph. The space of the cochlear duct arranged between the
Reissner's membrane and the upper boundary of the organ of Corti - the tectorial membrane
It is occupied by endolymph, a fluid similar to intracellular fluid (see figures 3.12 and 3.13).

FIGURE 3.12. Organ of Corti. It especially shows the hair cells and the
tectorial membrane against the ciliary projections. (Guyton, 1987, p. 405)

FIGURE 3.13. Simulation of the hair cells by the back-and-forth movement of the
cilia of the tectorial membrane.

The basilar membrane plays an important role in tone encoding of the

sounds thanks to the local differential characteristics of the cells that make it up.
All of them can vibrate, but those at the base of the snail are shorter, firmer, and
both, suitable for responding to high frequencies, while in the helicotrema they are more
broad and adapt to low-frequency vibrations. In the organ of Corti there are
different types of cells: receptor cells, hair cells or with hairs, phalangeal cells and
supports, placed on both sides of the Corti tunnel, formed by the rigid pillars of
same name, which continues along the upper area in the reticular layer. The cells
receptors are unevenly distributed on both sides of the tunnel, being more abundant
in the outer zone than in the inner one. The hair cells of the auditory cells cross the
reticular lamina and those of the outer zone are anchored in the gelatinous tectorial membrane,
fixation that limits the movements of these cells when vibrating and forces that
this membrane is displaced dragged by the movements of the cells. The cilia
of the
internal receptor cells are not fixed to the tectorial membrane but rather touch it
when they vibrate.
The vibrations of the stirrup in the oval window membrane are first transmitted to the
perilymph of the vestibular ramp, from where vibrational waves originate by the ear
internal that cause increases in pressure. When the stirrup strikes the membrane very
Slowly, the vibrations flow to the helicotrema, reaching through this route the
tympanic ramp, and they reach the membrane of the round window, which curves towards
the temporal bone, which causes displacements of the basilar membrane in the direction
opposite. This effect is favored by the smaller amount of liquid disposed between the
base cells that are between those of the apex. If, on the contrary, the stirrup vibrates
quickly the wave does not reach the helicotrema, but the basilar membrane undulates
downwards with each hit. The proximity of the vestibular apparatus determines that the
snail vibrations affect the area adjacent to the auditory region (see figures 3.14 and
3.15).

FIGURE 3.14. Schematic view of an embryo's ear, showing the helicotrema that
complete the flow path from the oval window to the round window. The scale
the vestibule and the tympanic scale form a single fluid chamber, divided along
for the greater part of its length by the basilar membrane. (Bridgeman, 1988, p. 117)

FIGURE 3.15. Movement of fluid in the cochlea after the forward push
of the stirrup. (Guyton, 1987, p. 403)

The receptor cells are electrically activated due to an ionic exchange between
the intra and extracellular environments caused by the displacements of the
basilar membrane, which induces both those of the cells themselves and the inclination
of the hairs. The exchange of ions alters the resting or equilibrium state of these
cells and generate small electric potentials that are captured by the
receptor extensions of neurons and transmitted to the auditory structures of the
central nervous system.
The differential features of the basilar membrane are fundamental to understanding how
The inner ear can provide appropriate clues about the tone of sounds. The greatest
ease for the vibration of the base area and the least amount of liquid to
displace, aspects already mentioned, prevent vibrations from clustering and mixing in
the base and determine that high tones create more vibrations in the base of the
snail and more electrical signals in the receptor cells of that area, while
graves affect more the region of the apex.
In fact, due to the blows of the stirrup on the membrane of the oval window, it vibrates.
a large part of the basilar membrane, but the vibrations increase in the area
"tuned" to the frequency of the original sound. In addition, this fact causes a
loss of vibration strength, which stops the "trip" of the wave throughout the rest of
the membrane.
The tuning of the cells of the basilar membrane to a given frequency was
postulated by Helmholtz and proven by Von Bekésy who designed the graphs of
movement of the basilar membrane for different frequencies. However, this
tuning mechanism is not effective for encoding tones of frequencies below
1000 Hz, which cause vibrations in wider areas of the basilar membrane, and the
the strategy of the auditory system to encode these tones is different. The hair cells
that are supported on the basilar membrane are surrounded by the extensions
receptors of the neurons that make up each member of the VII cranial nerve, called the
acoustic state. It is precisely these cells (about 30,000 in each ear) that
in charge of transferring the signals caused by the vibrations in the membrane
basilar and, ultimately, in the hair cells up to the auditory nerve centers in
those that complete the processing of signals. In the case of frequency tones
below 1000 Hz, certain neurons adjust their firing rate - number of impulses
nervous for a second - to the frequency of sound. Thus, in the face of tones of 800 Hz
specific neurons that record signals from hair cells in the nearby area
snail's apex, 'they will fire' and transmit 800 impulses per second; in response to sounds
of 634 Hz, others
they will display a rate of 634 impulses per second, so that each frequency
original is mimetized in a small group of neurons, as long as the
the number of Hz or cycles does not exceed its temporal resolution of activity, limited by the
refractory state of inactivity between two successive impulses. The tuning of the
fibers or extensions of nerve cells do not exclude responses to others
frequencies. Thus, low-frequency tones, poorly defined by the membrane
basilar, they are encoded through the reproduction of their frequencies, mechanism
that Rutherford had proposed in the last century. For high-frequency tones -
impossible to follow by any neuron - the principle of also works
"andanada", stated by Wever (1949) and verified by Rose et al. in the year
1967, which proposes the synchronization of the discharges of a group of neurons in a manner
that among all reproduces the original frequency of a tone. For example, in a group
of
five neurons -NI, N2, N3, N4, N5- each can 'mark' -fire- a vibration
and wave of every 5, so that NI does not do it before the first, sixth, etc., N2 before the
second, seventh, etc., N3 before the third, eighth, etc... and so on among the five reproduce
a tone of, for example, 5,000 Hz. The signals of the five must converge into others.
nerve cells of the central nervous system, the part of the nervous system contained in
the cranio-spinal axis. Since auditory signals are conducted by cranial nerves.
the auditory centers are all located in the cranial or cephalic area. It could be said that
the cells where convergence occurs are 'informed' of the frequency of the
tone.
Another aspect of sounds that must be communicated to the auditory centers of the brain.
it is its intensity or, in other words, the amplitude of sound waves. In this case the
the encoding mechanism of the inner ear is double: the intensity of the vibrations of
the cells of the basilar membrane, which affects the hair cells and
in the auditory nerve fibers, and the number of affected hair cells, which
increases with the intensity of sound. There are also some hair cells that only
they are activated in response to very intense sounds. The human ability to discriminate sounds of
different intensity is very broad.
Up to this point, the auditory apparatus has been described, and aspects related to its
functioning, and there has been talk of the existence of hearing centers in the
brain that processes the signals transmitted by the vestibulocochlear nerve.
What happens in these centers will be the focus of the rest of this section.
The number of central auditory centers, their connections, and therefore their complexity
they are enormous (see figure 3.16). What is collected in each ear is processed in groups of
nerve cells located on both sides and at different levels of the brain: the trunk or
brainstem, the portion immediately above the spinal cord, the thalamus, which
it is located above the brainstem, and also in the medial area of the brain, and the
zone of the cerebral cortex, or outer layer of the cerebral hemispheres, that is located beneath
the upper part of the temporal bone. At these three levels there are centers
auditory processors. In all of them, a 'tonotopic' organization persists, as in
the cochlea. It can be stated that the basilar membrane is 'represented' in various
hearing centers (it seems that the number of those representations or maps rises to
once), which means that in eleven auditory centers there are groups of neurons
that process signals coming from points -and from specific tones of the membrane
basilar. The total number of groups in a center deal with sounds from the entire audible spectrum. For
Another part, there are numerous, if not all, hearing centers that can "control" the
firing rate of neurons from other centers located at a lower level, or even
from the cochlea, in such a way that they can "suppress" or "attenuate" certain signals and/or highlight
others. This possibility is of great interest to "attend to" some messages and
"reject" others.

FIGURE 3.16. Auditory pathway. (Modified from Crosby, Humphrey, and Lauer: Correlative
Anatomy of the Nervous System. New York. The Macmillan Co.). (Guyton, 1987, p.
408)
Nerve cells from the reticular activating system also receive auditory signals.
brainstem, which plays an important role in 'waking up' or activating the
crust so that the information that is transmitted is processed in 'good conditions'
and the organism prepares to respond. The cerebellum, a small structure that
intervenes in the organization and correction of movements, also receives promptly
information about events occurring in the auditory space that allows you to
coordinate responses to auditory signals, such as head turns to locate the
sound source, etc.
The auditory centers where signals from the cochlea first arrive - conducted by
The statoacoustic nerves are the cochlear nuclei. Some of the neurons of these
nuclei seem to indicate the arrival of signals, as they only trigger when the
first contact and then they remain silent; others only fire when the
transmission of the message, that is, when the contacts between the elements end
terminals of the nerve fibers and those of the nucleus; others, finally, respond to the
contacts all the time, and they increase the firing rate during the
signal transmission. This diversity of situations faced by the cochlear cells
The response is likely due to the fact that processing takes place in these nuclei.
different aspects of sounds.
From the cochlear nuclei, three groups of nerve fibers originate, the most
important of them reaches the upper median olive, a small set of neurons that
receives signals collected in both ears. Given its importance for localization of the
the source of the sound will be discussed later some functional aspects. From there
one of the "control" beams of the information being transmitted is originated to
central nervous system.
The bundle of nerve fibers that ascends from the cochlear nuclei receives the
name of the lateral lemniscal tract (in fact there is a tract on each side). Some
"relevant" or transmit signals to nerve cells located a little higher up from the
cochlear nuclei, in the nuclei of the lateral lemniscus, whose long branches are incorporated
to the beam of the lemniscate, which, in turn, reach other centers located even higher in the
brainstem - the inferior colliculi -. Both the two lemnisci and the two colliculi
they are interconnected, so they have access to and process captured information
for
the two ears. From the colliculi, the pathway continues to the geniculate bodies
medial
from the thalamus, which project nerve fibers to the primary auditory cortical area,
located, as previously mentioned, in the region immediately underlying the bones
temporal. The tonotopic map of the auditory cortex is the most extensive of the route
traced up to here. The area of the base of the basilar membrane is represented in a
extreme of the assigned cortex band for auditory signal processing, and the
apex, in the
Another. The frequency band around 6,000 Hz seems to have a
broader representation, which is equivalent to saying that it receives treatment
preferential. But there are numerous difficulties in the experimental verification of
these maps given the depressant effects of anesthesia that alter the conditions in
that signals are processed under natural circumstances. Like other sensory areas of
the cerebral cortex, the auditory one is organized into functional modules, arranged
perpendicular to its surface and made up of a variable number of neurons
whose bodies
cells are found at different levels of depth. These modules are
"information processing circuits". Another form of organization common to the
sensory cortices are made up of "strips" or horizontal layers of neurons that seem
exhibit "preference" for traits of signals such as, for example, in the cortex
auditory, its binaural or monaural origin. This preference is manifested in
more vigorous responses to the preferred traits. Another aspect of, at least, some
of the nerve cells in the auditory cortex is their selectivity to the range of
frequencies that respond. It really seems that, along the way, it is being refined
the spectrum of tones, enhancing access to different neurons of signals
corresponding to an increasingly narrower range of frequencies while limiting others.
Through this mechanism of progressive channeling, the neurons of the cortex
auditory responses fire strongly upon the arrival of the signals of preferred tones and they
they inhibit in the presence of tones close to these.
Many functional aspects of the auditory cortex are unknown, especially those
regarding the integration and recognition of sounds, processes in which they participate
also other areas of the auditory cortex connected with the primary.
Some authors have ironically questioned the need for an auditory cortex,
given the complexity of the pathway and the exhaustiveness of extracortical auditory centers.
The consequences of injuries can better illustrate their functions. In
first, lesions of the auditory cortex of one cerebral hemisphere do not alter
substantially the perception of the frequencies of sounds, which does not result
surprising if we consider that most hearing centers receive
information captured by both ears. In total absence of the auditory cortex, injury
bilateral, the cats, which have been the animals most used as subjects of
experimentation on this cortical area responds to changes in frequency and
intensity of sounds. However, they show deficits in tasks such as that of
discrimination of sound patterns, which involves the comparison between different tones,
and the duration of sounds. In
In general, it seems that the auditory cortex is involved in complex functions such as that of
detect changes in frequencies, distinguish between specific patterns of sounds and, in
humans, from speech perception, whose meaning is extracted in other areas of
the cortex. Another function for which its integrity is indispensable is to locate
sounds in space.

3.2. Sound discrimination

As we will observe regarding touch, it seems that some levels

apparently very impermeable in the perceptual process can be shown
functionally influenced by subject variables. In principle, no research
he has found clear differences between seers and blind people regarding
ability to discriminate or distinguish sounds. However, differences appear
when the task requires the activation of other cognitive mechanisms.
For example, Witkin, Oltman, Chase, and Friedman (1971) had their subjects
identify some simple auditory patterns within auditory patterns
complexes, attributing the best performance in the task of the blind to a greater
attentional capacity. In the same sense
research suggests that they find a more satisfactory performance in the
blind people in sighted individuals in classical tasks of vigilance and signal detection. It
important of this data, it is worth noting, is that the perceptual thresholds
auditory were equivalent in blind and sighted individuals, except, perhaps, for the frequencies
high frequencies (from 10,000 Hz), apparently involved frequencies, as we will see more
down, in obstacle detection. Moreover, some researchers have managed
high correlations between mobility scores and discrimination task scores
sounds, which has led to the belief that greater contact with auditory stimulation
environmental makes blind mobility experts pay more attention to the
variations in frequency or intensity that occur in sound sources.
On the other hand, in long-term recognition tasks of sounds produced by
family objects no differences have been found between the blind and the sighted (Cobb,
Lawrence and Nelson, 1979). Everything seems to indicate, as we have also seen in the case
of touch, that when categorical perception processes are put into operation the
the differences between blind and sighted people barely exist. Once the information is
The blind do not have to show a more adequate performance than the others.
seers in this type of tasks.

3.3. The localization of sound sources

Most of the available work on sound source localization

it seems to indicate that there are no differences regarding this skill between the blind and
blind people, although it seems that late-blind individuals are more successful than sighted people
and that early blind individuals use acoustic cues to locate objects in the environment; something
similar seems to occur with distance estimation tasks. In this sense,
Wanet and Veraart (1985) designed an interesting sound localization task in the
space in which they intended to control the distance of the source and its angular orientation
Regarding the subject. Among other interesting results, they found that blind people
early ones made more accurate distance estimates than late blind ones and that
the seers, although these differences were not as clear in the case of the
direction estimates. Furthermore, subjects were asked to make their estimates at
through two response modalities: motor (pointing) and verbal (row 1, column
Well, early blind people were more effective when making estimates of
distance through verbal responses than when they did it through answers
motors. However, when they made direction estimations, exactly the same happened
contrary. Regardless of its theoretical justification, it seems that these results allow
extract some practical recommendation. Specifically, one could think that the
walking aid devices that use the acoustic channel should
focus more on distance estimation than on direction estimation, although
the ear is specially prepared for this function.
The estimation of the origin of sound based on acoustic signals is really
impossible when the sound source is located directly in front of or behind the
midline of the body and, therefore, sound waves arrive simultaneously and with the
same intensity to both ears, equidistant and with the same orientation with respect to
that source. But if the sound is produced slightly to the right or to the left of the
the midline of the body, the ear closest to the sound source receives the waves with
prior and/or with greater intensity than the farthest. The auditory system,
Well, it bases the mechanism of sound source localization on differences.
temporal or intensity between the signals produced in both ears in response to the
arrival of the waves (see figure 3.17).

FIGURE 3.17. Physical cues for sound localization. a) the difference in

intensity as a signal. The nearest ear receives a more intense sound due to its
proximity and because the other ear is in the area where the head casts a shadow
sound. b) The time difference (phase) as a signal. A pressure wave will arrive
slightly closer to the nearest ear.
(Bridgeman, 1988, p. 114)

As such differences are minimal, we must attribute to it an extraordinary

discriminability. Let's analyze each of these clues. The binaural delay or lag in
the reception of sound varies depending on the position of the head in relation to the source
of the sound, being maximum when it is located laterally to one of them. The ear
distant takes time to receive the waves the time taken by them to cover the distance that
separate both ears, in this case the diameter of the head, about 18 cm
approximately. Given that the speed of sound propagation is known (335.5
mis) and the distance to cover - half the circumference of the head, 1t X r, 3.14 x 9 ;
28.26 - this time can be calculated. The maximum interaural delay is 843 milliseconds.
approximately seconds (if the sound takes 10,000 milliseconds to travel 33,550
cm., it will take 28.26 cm: 28.26 X 10,000 / 33,550 = 282,600 / 33,550 = 843
milliseconds). The time delay implies a lag in the capture of the waves by
part of the two ears: the second ear receives the message when the first has already
captured a certain number of waves, variable according to the frequency. In the tones
at high frequencies the phase shift is practically imperceptible, given the high frequency of the waves; in
change in the lower tones, low frequency, a phase shift of even one cycle results
appreciable for the auditory system.
The other clue we referred to earlier alluded to differences in intensity. It has been
commented as when a wave hits an obstacle it loses strength, or 'height'.
Larger waves are less likely to deform since the
the probability of "overcoming" obstacles encountered in their path is greater.
Obviously, the size of the waves of low tones is greater than that of high tones (if
At 335.5 m, or 33,550 cm, 100 waves occur, each measuring 335.50 cm;
a tone of 10,000 waves its size is 3.35 cm). Thus, it can be concluded that the
low sounds, much larger than the head, surround it cleanly and that the
sharp sounds collide with her and weaken. It has been calculated that a tone of about 1,100 Hz is
perceives with an intensity of about 4 dB more in the ear closest to the sound source.
Now we must ask ourselves how the nervous system analyzes such differences. The
available data come from studies conducted on owls by Knudsen and Konishi
(1978) and, to a lesser extent, in mammals. In owls, the mechanism to locate the
the source of sound is also based on comparisons of intensity and phase difference, aspects
that are processed in independent channels in the auditory pathway from the first nuclei
also called cochlear. The delay channel has neural elements.
tuned to different delays that are refined from the early stages and
they end up transforming temporal information (the right ear has received it before the
left the information) into location information (then the sound comes from the side
right"), with a degree of precision that is truly impressive. Obtained.
neuron recordings at high levels of the auditory pathway that only show activity if
The sound is positioned at a certain point in the auditory space and is inhibited (not
respondents) if they come from nearby points. In primates, there seem to be devices
similar. Other findings, this time in cats, refer to the characteristics of neurons.
cortical areas that show activity when the sound source is mobile and moves in
a certain direction, and that they are inhibited in the face of other directions, while others
neurons only respond to static sound sources, located at points
spatial. In any case, the cerebral cortex of mammals seems to play a
key role in the precise localization of the sound source.
There are other factors that contribute to the localization of sounds, such as,
the shape of the ear, as appears to be deduced from experiments in which the smoothing
The folds of the ear pavilion with fillings reduce discriminability.
Possibly, the reason lies in the way sound waves are reflected off them.
that provoke echoes that vary depending on the locations of the sound source.
Additionally, when it is equidistant from both ears, head turns occur that
allow for establishing differences that serve as clues. On the other hand, also
cognitive factors seem to be involved, which can cooperate with the auditory ones, such as
the knowledge of space. In closed spaces, the dimensions, the distance between the
listener and the sound emitter, and both in relation to walls, floor, and ceiling, as well as the
the degree of sound absorption and reverberation creates differences that intervene
possibly in resolving the issue. To the information provided by the arrival
direct sound from the source is subsequently added to the successive one
it reaches the ears coming from the walls of the room. It is likely that it can be
make the most of it even if no data is available.
Sight and hearing must cooperate in this function, as the presence of seems to suggest.
neurons that respond to auditory stimuli located at specific points of the
space in the visual cortex, a map that is not exclusively auditory but also
visual (World, 1972). The meaning of this data is unclear but supports the idea of
There should be a visual-auditory interaction to locate stimuli in the
space with a precision superior to that provided exclusively by the system
auditory, effective although sometimes ambiguous.

3.4. The 'sense of the obstacle'

The ability to detect obstacles, apparently linked to the localization of sources
of sound, is, surely, one of the perceptual functions in which there have been
systematically found more differences between the blind and the sighted. The
called 'facial vision' or 'obstacle sense' is undoubtedly the phenomenon
more exotic and more striking than any that appear in the perceptual world of
the blind. Supposedly, in addition, its importance in wandering and in the elaboration of
spatial representations of the environment, it should not surprise us that it stands as one of the
phenomena that has led to the most research in this field for over 50
years. Indeed, many blind people "feel" that they can detect obstacles, although in
they are rarely aware of the nature of the phenomenon, that is, they rarely know
how they can do it.
The 'sense of the obstacle' generated a good number in the 1940s and 1950s
investigations in which, in general terms, accounted for the nature
acoustics of the phenomenon (see, for example, Warren, 1978). Other hypotheses until then
current ones indicated that obstacle detection could be based on pressure of the
air or in olfactory keys, not to mention more imaginative hypotheses (see Ananiev et al.)
et al., op. cit.). These works also highlighted the importance of learning in the
development of this function, so that the differences found between blind people and
seers tended to disappear after a certain period of training. In addition, they
Hello, the most important sonic frequencies in obstacle detection were the
frequencies higher than 10,000 Hz, a finding consistent with the fact that the
organisms that use acoustic indices to orient themselves in the environment (bats,
for example) they usually present vocal systems prepared to emit high sounds
frequency and auditory systems prepared to record the reflexes of those sounds
in the objects. Lastly, it is worth noting that early blind individuals, it seems logical,
they develop this function more than the late ones. .
So that the reader not familiar with the phenomenon can understand it a little better,
we will briefly describe a recent work through which replication is intended
some of the classic works mentioned above. Strelow and Brabyn (1982)
they used a group of totally blind individuals and a group of sighted individuals and subjected them to two types
of tasks in a soundproof room. In the first task, the subjects had to
follow a path parallel to a 1.7 m high fence and in the second task the
subjects had to follow a trajectory parallel to a row of posts 1.7 m high by
15 or 5 cm wide. The adjustment to the trajectory was measured through a system.
computerized and the most notable mobility errors were also taken into account
for example, crashing into obstacles or leaving the platform that delimited the
trajectory). The results indicated that the blind performed the task better.
truth is that the seers made fewer mobility errors. On the other hand, the
the task of the posts was much more complex for the blind than the task of the fence. It
it was verified that no blind subject used more sounds than the noise of their footsteps. In
any case, and with
In order to ensure the acoustic nature of the phenomenon, Strelow and Brabyn conducted.
the same tasks with a blind adult and with two new variants: in the first, it
it introduced a wide spectrum masking sound of about 50 dB; in the second
variant, the subject performed the task with an industrial acoustic shield. The subject took to
I finish the fence task under normal acoustic conditions and then in the two.
acoustic suppression conditions. The results showed a clearly executed
inferior in the last two conditions, which seems to justify the importance of the
acoustic indices in obstacle detection.
The available data about the 'sense of obstacle' have in many cases suggested
the concrete decision-making regarding applied problems, especially in
the field of orientation and mobility. Some specialists have pointed out, for
an example that the use of mobility aids (guide dogs or canes) could reach
inhibit the use of more natural skills such as the one we have been discussing in
this section.
On the other hand, since sounds allow for the detection of obstacles, nothing more
appropriate to equip the blind with a system that emits sounds. The results of this
philosophy was very hopeful and it didn't take long for the logical culmination of the
same: the famous Sonic Aid, developed by Leslie Kay. The design is logically
simple although technologically complex. A device emits ultrasonic signals
which, once reflected in objects, transforms for the subject into a complicated
acoustic signal. Both the surface of the object and its distance or spatial arrangement
can be detected through systematic variations of this signal. In any
It seems that proper use of the device requires training.
exhaustive and costly. It also raises the problem that the interpretation of the
Acoustic signals demand too many attentional resources, so the user can
forget to use other fundamental acoustic, tactile or olfactory clues in the
wandering. In any case, the overall utility of the Sonic Aid must still be
evaluated.
Regarding the social functionality of the auditory system in blind individuals, the scarce
available research so far suggests that the blind
they discriminate better between human voices than sighted people (e.g., Bull, Rathborn and
Clifford, 1983), although we again encounter the problem of figuring out if this
the phenomenon is strictly perceptual or has more to do with the functioning of
other cognitive mechanisms (attentional, in this case).

3.5. The role of hearing in the perceptual development of the blind

In general, the available data on the development of auditory perception in children

blind people are comparable to those available about the development of tactile perception.
That is, there are no differences between blind and sighted individuals regarding the
execution of psychophysical tasks (discrimination of phonemes or generalization of
tones) (Stankov and Spilsbury, 1980), while the data begin to become more
difficult to interpret when it is required of the subjects to carry out tasks with
higher cognitive requirements. For example, some authors have shown that the
blind children are better than the sighted at tasks of extracting short sequences of
sounds of more complex sequences (Witkin et al., 1971) and that have a greater
memory amplitude for letters when they are presented acoustically (Gibbs and
Rice, 1974).
The ear contributes, especially in the case of visually impaired individuals, to estimation.
of distances and the localization of elements in space. However, research
About the development of this function in blind children is very scarce. Nevertheless, it seems
that we can venture some idea in this regard. In relation to the famous "sense of
Obstacle", everything seems to indicate that it already reaches a certain level of development before the
adult age, although individual differences are very pronounced (Worchel, Mauney and
Andrew, 1950; cited by Warren, 1984). Regarding the tasks of locating sources
of sound in space, the data turn out to be somewhat contradictory. In any
In this case, we can point out that in adult blind individuals the ability to detect the presence of
obstacles based on acoustic indices negatively correlate with age of
access to blindness (Rice, 1970; Juurmaa and Jarvilehto, 1965), although with children the
results are not so clear. In any case, it seems necessary
that investigations are carried out in which fundamental variables such as age
access to blindness or visual status should be more systematically controlled. It is
It is also necessary that evolutionary work on the contributions of the
audition to the perception of some aspects of texture and to the identification of
objects or people.
On another note, it seems absolutely necessary to analyze the role of the remains.
visuals in the overall perceptual development of the blind. So far, most of
Attempts in this field have been carried out from an applied perspective, this
Yes, efforts have been made to determine to what extent the functional use of the remains
Visuals can improve the adjustment of visually impaired children to their environment. In this sense, the
works by Barraga and his collaborators (e.g., Barraga, 1964) have represented a
continues to be a source of inspiration for research in this field.

4. The external chemical senses

The category of chemical senses includes the internal ones, such as the detection of
oxygen levels, carbon dioxide, glucose, etc., for the maintenance of
internal means, which are not perceived, and the external ones, taste and smell, that
we will address here. In these latest, the signals from the environment are related to the
needs of the internal environment and their satisfaction are perceived with an emotional nuance. From
Indeed, the olfactory pathway includes fibers that transmit signals directly to
nervous structures responsible for emotion and memory. Although in a more
Indirectly, the 'taste' signals also access such structures. From the point
From a phylogenetic point of view, taste and smell develop early. For all these reasons, we
they consider primitive senses.

4.1. Taste

Strictly speaking, the taste experience is provided by both the sense of

I enjoy it like through the sense of smell, as demonstrated by the lack of flavor that
we attribute to foods when we have a cold. Receptors of others
modalities, such as those of texture, also seem to play a role in the
taste perception. Despite this, when it comes to describing this sensory modality, one
these contributions to taste are omitted and only the specifically
tasting.
Taste receptors are cells similar to those of the skin, but located within
the oral cavity, grouped in groups of 50 in taste buds (see figure 3.18).

FIGURE 3.18. Taste bud. The chemical substances that enter through the pore
taste generate an electrical signal in the button. (Adapted from Murray and Murray,
1970.) (Goldstein, 1988, p. 33. Reproduced with permission from the publisher Debate)

Forming part of these buttons are other cells, such as those called
basics that, in a renewal process lasting about 10 days -and more
quickly during childhood - they begin to replace the taste receptors that
They die. Each button is embedded in the epithelium of the tongue and communicates with its
external surface through a channel from which the tiny hairs emerge
receptors where it seems that the uptake of stimuli occurs. The buttons, in turn, are
they group together forming papillae that take on different shapes and are distributed
irregularly on the tongue. In humans, there are three types of papillae: fungiform,
foliaceous and circumvallate, whose situation, shape and taste preferences are quite
specific. The fungiform ones look like small mushrooms, contain few buttons,
they occupy the two-thirds of the tongue and mainly respond to flavors
sweet and salty. The foliate papillae form leaves at the posterior end of the tongue and
they show a certain preference for sour flavors. The circumvallated are
large, round and are surrounded by a kind of prominence; they occupy one third
the back of the tongue and primarily respond to bitter tastes. The number
The number of buttons in these last two types is very high. In the epiglottis, in the third
Taste buds are also located in the upper part of the esophagus and in the palate.
There are three nerves that provide innervation to the taste receptors: the VII pair
cranial or facial, whose branches innervate the fungiform papillae, the IX cranial nerve or
glossopharyngeal, which connects with the other two types of papillae, and the X or vagus, which arrives
up to the taste buds of the esophagus and palate. Once in the nervous system
central -in the brainstem, to be more precise- the taste fibers of these three
nerves form a bundle known as the solitary tract that reaches a set of
neurons, the solitary nucleus, also targeted by fibers from other viscera.
From this nucleus originates a dual pathway for taste information. One of them
it mediates the perception and recognition of flavors and is similar to the one described for the
rest of the sensory modalities: reaches a thalamic nucleus which, in turn, transmits
to the gustatory area of the cerebral cortex, which coincides with the area of cortex
somatosensory corresponding to the tongue (see figure 3.19). The other pathway reaches
nervous structures underlying survival behaviors and processes
emotional and seems to be related to the affective aspects of perception
gustatory, with the avoidance or preference of certain flavors, etc.

FIGURE 3.19. Transmission of taste impulses to the central nervous system.

(Guyton: 1987, p.417) - .

The existence of four basic flavors and areas of the tongue with greater density of
A type of papillae has favored the idea of absolute specificity of receptors, fibers.
nervous transmitters, etc., for a certain taste. Thus, it has been assumed that the
sweet substances only affect the fungiform papillae and, therefore, the fibers that them
They innervate the neurons of the relay nuclei to which they transmit. This type

102 Florentino Blanco and María Eugenia Rubio

The proposed encoding is called "marked line" and presented as such

terms is incorrect. It has been verified that the experimental application of substances
of different flavor in a certain button triggers responses in the receptors that
it contains, although the magnitude of such response is variable. It can be postulated that the
receptors, fibers, etc., exhibit a certain preference for a certain flavor. The
the code used is, well, preferred line more than marked. In the situations
daily, in which we consume substances composed of various ingredients - and, for
so, they do not have pure flavors - which are also distributed by the movements of the
tongue throughout the oral cavity, it is necessary to activate most of the
taste receptors so the relay stations and/or the gustatory cortex must
evaluate the level of activation of each connection line by comparing it with
the remaining ones, a process that would result in the perception of the different flavors of the
food in question, as well as its amount. It has been verified that, as
increases the concentration of a substance on the tongue, the response of the receptors and
the nerve fibers becomes greater, making their recognition easier. It is
likely, furthermore, that a smaller amount of substance will be needed to produce a
increase in response in the receptors that exhibit a preference for it over the
that they do not exhibit. However, in the presence of concentrations of different substances
composition applied in different areas of the tongue the responses of the receptors are
they could match and
make it difficult for their recognition, unless the higher nervous centers attended,
In addition to the magnitude of the receiver's response, to the identification code of the line (
from what point it originates, what type of papilla it innervates, etc...
Some aspects of taste perception seem to be genetically determined.
as aversions to harmful substances - certain poisons of strong flavor
bitter-. Others are the result of associations established during the course of life and can
also result vital for survival or from a hedonic point of view.

4.2. Smell

Anatomy and physiology

In general, it has been considered that the influence of smell on human behavior is
somewhat decisive, especially when compared to animals in which behaviors of
survival, such as mating, caring for offspring, searching for food,
the avoidance of 'marked' territories by other conspecifics, the relocation of members
deaths of a community to the waste area, etc. are triggered or are modulated
from olfactory stimuli. In recent decades, signals have been attributed to
olfactory play a role in the synchronization of menstrual cycles among women who
they live or work together, which has led to a reassessment of the real importance of
this sense in man.
The basis for the relegation of smell in men may be due to various concepts.
erroneous ones developed from data obtained in experiments conducted with a
inadequate methodology. Such inadequacy has been due to the lack of resources.
techniques that will enable a homogeneous distribution of odoriferous substances
test object in the receiving area, or for not considering the limited vocabulary
popular related to smells. This is why it has been proposed that the thresholds for
detect and discriminate odors are very high. On the other hand, the relative
inaccessibility of the olfactory mucosa, which occupies an area of 5 cm2 in the poster zone
the superior of the nasal cavities has also contributed to a limited understanding and
mistaken sense of smell and, consequently, its consideration as a secondary sense
(Goldstein, 1988).
In the olfactory mucosa, there are various types of cells that, over a cycle of 60
days, they go from being basal cells to supporting cells and, subsequently, cells
receptors (see figure 3.20).

FIGURE 3.20. Organization of the olfactory membrane. (Guyton, 1987, p. 420)

The olfactory receptors are neurons with two extensions, one oriented towards the
periphery of the olfactory mucosa and the other towards the basal area of the brain. The
the receiving extension has an expansion from where hair-like structures or cilia originate,
arranged in a network form, which reaches the surface of the mucosa where it is placed in
contact with olfactory stimuli -volatile odor molecules- has been postulated
that the cilia have specific sites for them. The structure, shape, and properties
the chemistry of said molecules determines the type of placement they can have
"occupy." The different smells perceived would be given, then, by the characteristics of
the molecules and the selectivity of the receptors. Although Amoore found a relationship
between the shape and the type of odor perceived by experimental subjects, this is far from being
perfect. In fact, it has been found that different molecules can evoke smells.
similar and vice versa, so it must be considered that there are other factors that may
affect the process. It has been suggested that different odorant molecules are distributed
differentially by the receiving area, which preferentially activates.
receptors located higher or lower in the mucosa, which would also contribute to
its relative selectivity.
The extensions of the olfactory neurons that orient towards the brain
they constitute the first cranial pair, olfactory nerves, which reach the bulbs
olfactory, elongated structures located at the base of the brain. They are characterized by
an organization in groups of neurons or glomeruli, formed by the
terminations of the neurons that come from the mucosa and other local neurons.
Both the fibers of the first cranial pair and the olfactory bulbs, the first centers
olfactory cerebrals, are also characterized by a certain specificity regarding the
type of stimulus, as already seen in the sense of taste. In the olfactory bulbs of
It has been proven that there are areas that show greater activity in response to certain odors.
and lower before others (detected by an increase in the uptake of a substance
radioactive that contains glucose, necessary for the functioning of the brain.
From the olfactory bulbs, the information related to olfactory stimuli is
it distributes across various brain areas (see figures 3.21 and 3.22).

FIGURE 3.21. Olfactory pathways. The skull has been sectioned along the midline, and
the left frontal lobe has been sectioned along a frontal plane, that is, vertical and
transverse.
(Bridgeman, 1988, p. 143) . ¡

FIGURE 3.22. Neural connections of the olfactory system. (Guyton, 1987, p. 419)

Some are involved in the conscious perception of smell, such as the so-called cortex.
orbital; others associated with memory, such as the hippocampus. In general, they can be
classify into medial regions, responsible for the simplest aspects of the
olfactory perception, and lateral regions, responsible for the more complex aspects,
like the visuo-olfactory association. From these regions, information is distributed to
almost all the structures of the limbic system 'emotional brain', which is involved in
survival behaviors.

The chemical senses and blindness

Although it seems undeniable that the sense of smell can play important roles in the
The daily life of visually impaired individuals has barely received attention in recent times.
years. The case of taste seems even more dramatic, as we have not been able to find either
a single study on the subject. Indeed, most of the work carried out on
The studies on the sense of smell in blind individuals are quite old and lack sophistication.
experimental. In addition, its results are likely a consequence of problems
methodological approaches are partially contradictory. On the other hand, all the works that
we have reviewed focusing on the comparison of blind and sighted individuals in tasks of
discrimination or identification of odors. In this regard, it is worth noting a series of
studies carried out at
cabo by Griesbach (1899) in which the blind seem to exhibit a sensitivity
absolute for smells superior to that of the seers. Some subsequent works
(Cherubina and Salis, 1957; Bocuzzi, 1962), seem to point more in the direction
contrary.
In an effort to mediate the dispute, Murphy and Cain (1986) submitted a group
of blind (late and early) and a group of sighted individuals, whose ages ranged between
19 and 66 years old, engaged in two tasks: one task of olfactory sensitivity and one task of
identification of odors. The sensitivity task was carried out on concentrations
increasing alcohol through a forced choice strategy between two alternatives
(a container with an increasing concentration of alcohol and another with water). If the
choice was incorrect (that is, if the subject chose the water) the increased.
concentration in the following essay, until establishing a level of concentration in the
that the subject maintained a stable selection criterion.
Regarding the task of odor identification, a sample of 80 odors was used.
everyday items (ammonia, mustard, pipe tobacco, potato chips, cheese, etc.). In both
tasks, the psychics had their eyes covered. Each subject carried out the tasks in three
sessions. In the identification task, the subjects received feedback on their response.
The results indicate that psychics have a higher absolute sensitivity.
developed than the blind, while they are better at the task of identification
of odors. Although the second statement can be justified without too much
problems, the first remains surprisingly notable. The authors point out that the
the fact that blind people have lower olfactory sensitivity may be due to the
neurological disorders usually associated with blindness (perinatal hypoxia,
meningitis, etc.). An additional result worth noting is that an
very high negative correlation between performance on the identification task and age
for both groups (-0.73 for the blind; -0.81 for the sighted). Also
they find that the error rate in the identification task decreases through the
sessions, although the advantage for the blind is always maintained.
The design does not allow us to determine what type of processes account for the advantage of the blind in the
identification task, nor does it distinguish in the analysis of results between early blind and
late. In any case, it seems that the sense of smell follows the same course of adaptation
functional as touch or hearing in visually impaired individuals, that is, the blind are not
better than psychics at detecting the presence of a smell, but once detected
the blind are more capable of categorizing it.

The experience of the world without vision

What is the nature of the inner world that a person must operate within?
absence of vision? What are your ideas about the world around you? To what extent
the lack of vision should imply a readjustment in the way we construct the
world? Issues of this kind have a lot to do with the interest that many
investigators generate the world of blindness. The impenetrability of the experience of
being blind from the experience of the visible world makes blindness become
an exciting scientific and human challenge.
As we have already noted, in any perceptual experience it is possible to distinguish,
from the phenomenological point of view, a subjective pole and an objective pole, a
component of the phenomenon that informs us about the modifications it causes in the
subject an environmental disturbance and a component of the phenomenon that informs about it
perturbation. The different perceptual systems can be organized along
construct objective-pole-subjective, that is, there would be systems whose phenomena
they would be more oriented towards the objective pole, like vision, and systems more oriented
towards the subjective pole, such as proprioception or the vestibular system. Touch is
would be located in an intermediate position between both poles. Various everyday situations
They can show the reader this ambiguous phenomenological nature with relative ease.
of touch. One, for example, your hands with fingers intertwined and check, if
pay attention, how your experience alternates between consideration
of each of the hands as an object of the world or as part of oneself. If a
the hand perceives cannot, at the same time, be perceived.
On the contrary, vision is presented to us from a phenomenological point of view,
entirely tyrannized by the disturbances of the environment, it always refers to the world.
We have no difficulties unless we alter our perceptual mechanisms.
artificially, to experience any visual experience as belonging to the
world and the objects that compose it.
The functionality and phenomenological nature of perceptual systems is
consequence of a long phylogenetic and historical drift. This long drift has
focused on a functional specialization of such systems regarding the different
energy forms of the medium and to 'certain space-time frequencies within
of the same. The enormous pregnance of the visual system as a mechanism of
distal perception and its high spatial resolution power easily generate
"externality attributions" regarding the content of individual experience and
they allow visual perception to be more binding than other types of experience
sensory.
However, it does not seem clear that mere stimulation of the visual receptors
It is a sufficient condition for objective visual experience. For such to occur
Objective experience is necessary for the stimulation of the receptors to operate on
a cognitive intention. Imagine the reader reflecting on the problem that
we are trying. It is likely that their eyes are directed towards some object of theirs
environment without

that, in no case, unless there is some disturbance in that environment

especially relevant and striking, inform you about the characteristics of it
object. This is the basic idea on which the Gibsonian distinction between touch is based.
active and passive and, in a generic way, their theory of perception. Active touch, the
haptic perception emphasizes the objective pole of the experience and facilitates attributions
of externality because it is linked to the intentional activity of the subject.
For all this, we can think (see chapter on development) that while the
structural restrictions of perceptual systems determined by drift
Phylogenetics can introduce some discrepancies in the construction of a stable world.
and permanent by the blind subjects, such construction may remain
guaranteed by the incorporation of intentions into the structure of the action. The
phenomenological differentiation between the objective pole and the subjective pole, between the I and
reality radically and ultimately depends on the subject experiencing itself
as an intentional instance. Some non-human systems can be perfect
spatial frequency analyzers but do not experience themselves as
subjects of intention.
It seems, therefore, that the possibility of building a stable and experienced world in
An 'objective sphere' separate from the sphere of the Self depends on intentional nature.
of human action. Evidently, the nature of the experience of the world must
to be limited by the means of access to it. In this sense, to represent something
Mentally, it consists of presenting it again. If someone has not experienced it.
Visually the world, it is hard to imagine it visually. It will have, in
consequence, to put into play other alternative codes of representation that are
will be extensively commented on in other chapters. The role of language is, in this sense,
crucial. As far as the subject can access a system of signs that appeal to
socially shared meanings can also have a system of
representation that links you to the world through tacit or express agreement with the other.
Language is all the more powerful and useful in the description and transformation of the world.
the greater its capacity to generate intersubjective consensus. In this sense,
Maturana and Varela (1990) have recently pointed out that it is not necessary to assume that
the knowledge of organisms is represented in such a way that it exists
knowledge as such. Knowledge would be encoded in structural possibilities
that provides the network of current connections between the sensory and the motor, in such a way that
the past, the memory, and, generically, the representations would only exist as
communicative categories among observers.
One can think that the world generated by the structural coupling between a
species and the environment is the only possible world with which the species can interact.
In this sense, the only problem is introduced by the possibility of access to other worlds.
perceptive (ribosomes, for example) guaranteed by the creation of instruments of
technological mediation (microscope), a fact that points to the idea that the mind
human beings generate "possible worlds" hypothetical beyond the worlds that brings to the
hand
the 'natural' structural coupling (the functions of knowledge). If the possibility.
to think about the existence of ribosomes or DNA is the consequence of the
inherent trust in a transcendent reality beyond restrictions
imposed by the structure of the organism or, rather, the result of a coupling
whose evolutionary resolution takes place over cultural and not natural structures is
a central issue that needs to be resolved. The use of mediation instruments
that are constructed and transmitted within specific socio-historical contexts
seems a crucial element in the generation of such possible worlds.
The psychological world of the blind is also a good point of reference to address.
to smell this problem of possible worlds and its socio-biological nature, and to
try to break the persistence of the procedural flow from predefined worlds of the
computationalists. Blind people can certainly build states.
representational about 'realities' that are not accessible by making inferences
spontaneous or directed based on inputs from other available sensory systems (for
example, estimate which of two streets one is on at a given moment based on the direction
from the circulation inferred from the sound of the engines), but they can also, the
What is more interesting, accessing representational states about 'realities' or not?
they present access indices (for example, some conventional aspects of the
geometry, such as perspective or projections onto the plane of figures
three-dimensional). We understand that this is possible thanks to the existence of meanings
socially shared and, as we will see below, thanks to the generation of
social attributions regarding the competence of the blind, factors that certainly,
they have a common nature.
But it is even more relevant, concerning the validity of the representations,
understood as strategies consequent to a structural coupling and preserved
by the organism, the case of late blind individuals. It deals in this case, trivializing the
issue, of an organism that can use representation strategies - that
they empirically translate into a certain way of solving some problems, of acting - that
the organic structure no longer guarantees. In this case, it seems evident, the nervous system
the organism would use, if we were faithful to the approach of Maturana and Varela (op.
competencies not structurally defined, that is, not defined by the system
of connections between the afferent and the efferent. The past, in these terms, is something more
a communicative anchor. The structural configuration of an organism does not
determines in the human being, and probably not in other organisms either, its
cognitive competence.
Following Valsiner (1984), we can assume that the deployment of competence
Cognition in humans is better understood as a case of an open system.
it involves accepting, on one hand, that it is not possible to predict the final outcome of a process
evolutionary based on the initial conditions of the system, and, on the other hand, that the result
The end can be reached by different paths. The indeterminacy and variability of
evolutionary process has to do with the interdependence between the organism in
development and its environment.
Yes, surely, in this context it makes sense to revisit the Gibsonian notion of
"affordance". As Gibson himself points out, "... I understand it as something that refers to
both to the environment and to the animal," an idea very close to "structural coupling" of
Maturana and Varela (op. cit), and whose difficulties we have already pointed out.
Both the notion of 'affordance' and that of 'structural coupling' are very
consistent when we talk about actions, but they fall short when we talk about
representations and meanings. In this sense, as Valsiner points out (loc. cit.),
The 'affordances' define the limits of the possible actions that an organism can perform.
to perform in a given situation, so that, for example, a ladder cannot be
used to climb by a three-month-old child. But what would happen in this case with a
paraplegic? Obviously, even though the action of climbing is not structurally associated with it.
allowed, it is very possible that the meaning that the ladder holds for the subject
It points towards the possibility of using it to go up.
The observation of the behavior of others regarding the objects in the environment, the
"representational simulation" or playful-symbolic of potential actions, and, what
it is more important, the social regulation of our relationships with objects is
factors as important or more important in cognitive development than possibilities
structural actions in harmony with the environment.
Let's return, to conclude, to the problem of intentions. The fact of being aware of
the importance of intention in the construction of knowledge should lead us to
to think about some issues of central importance that we will only briefly mention here.
Let's begin by specifying that the notion of intentionality is not understood in this
context in a sense as broad as the Husserlian. In any case, we do admit
that any act of knowledge is an intentional act -not in the judicative sense-
to the extent that it always has an object as a recipient. The social definition of
the intentions of knowledge, that is, of the objects that a blind person can access
it depends not only on perceptual status, but also, and above all, on social attributions
about the cognitive competencies of the blind. In other words, the structure of the
organisms (the impossibility of accessing light energy in the case of the blind
total) restricts the type of cognitive experience of them, but surely it does not
specific. Language can act within the frameworks of socialization as a
system through which the world is amplified and refracted for the blind to be able to
interact. One of the areas from which the attributions can be modified about
the socio-cognitive competence of the blind is precisely the realm of the
research on such competition, through a curious feedback loop
in which scientific explanation becomes a condition of possibility for
such modification.
Chapter 4
BLINDNESS AND PSYCHOLOGICAL DEVELOPMENT

HOPE OCHAIT A

The aim of this chapter is to provide the reader with an overview of the characteristics.
and peculiarities of the psychological development of blind people. We will try, by
, not only to describe how the development of blind people occurs from
the transition from birth to adulthood, but also explain why the absence of the system
visual can produce a certain 'model of psychological evolution.' It is necessary to have
keep in mind that when we talk about blind people -or people with severe visual impairment-
we do not refer to a homogeneous group. On the contrary, there is a great diversity among them
interindividual variability that makes us very cautious when talking about
"general characteristics" in its development. They exist as we saw in chapter 2-,
different etiologies that produce different types and degrees of deficiencies and that furthermore
they do it at different stages of life. But there are also variations related
with the child's family and social environment as well as with early and school education
that he/she could have received. These family and educational variables are also sources of
variability in the development-learning of the sighted population, but it is important
it is important to highlight here that, when interacting with the different types of blindness, they produce patterns
very different evolutionary.
Undoubtedly, despite the problems of excessive generalization that may arise, the
study of the characteristics or peculiarities of psychological development in
children affected in such an important sensory system as vision, have a double
interest. First of all, it is important when establishing the intervention guidelines
and education necessary to optimize the possibilities of development and learning of
children with severe visual impairments. It also has considerable theoretical interest.
for developmental psychology as it allows to study the importance it has
visual system in the human species, the possibility that alternative pathways may exist for
the development using other sensory systems and, above all, to put to the test the
plasticity of the human psychological system.
In the following pages, we present to the reader the most important characteristics of
psychological development when the visual system is lacking - or is seriously damaged - in
In general, we will focus on the case of the most severe deficiencies, that is, we will talk about
of children with total blindness who lost their sight in the early stages of life,
since most of the publications that appear in the literature on the subject are
they have done with this type of subjects. However, as was evident in the
first of the chapters of this book, the population of subjects with certain visual remnants
is greater than that of total blindness and, likewise, cases of loss are more frequent
late vision compared to those with congenital or very early blindness. Therefore, we will include in
this chapter, whenever possible, the maximum data about deficient children
visual and late blind. However, given that there are significant gaps in the
research on the development of these children, the reader will have to refer to their
knowledge about the psychology of development in sighted people for, at a given moment,
infer how the evolution of a certain child has occurred. For example, a child
that she has lost her sight after three or four years, she will have built
visually the early stages of the development of their intelligence, as well as the first
images and symbols. Likewise, the visual remains that a certain child has, and
the use that has been made of them may affect their development
it resembles more that of a seer than that of a blind person.
It is necessary, consequently, to insist again that the processes of
learning development that will be described below does not occur in a
rigid and identical for all blind people, since --as we have already said--, they depend
from the conjunction of a series of individual, family, social, and cultural factors.
We will analyze these factors of development in the last chapter of this volume. For the
At this moment we would like to point out that, in this chapter, we have aimed to highlight the
alternative ways that a blind child can use from the early stages of life
to build their psychological development in the absence of vision. Thus, their reading can
to result, for some, an 'optimistic' version of the capabilities of the blind.
Since we live in a culture where the visual system is very important,
our objective has been, precisely, to demonstrate that it is possible for the
blind people achieve a psychologically functional development equivalent to that of the sighted,
although through different ways or routes. Thus, we have tried to highlight those ways
alternatives to be considered by parents and educators. Without a doubt,
we can find blind children with developmental problems in early childhood, with
difficulties in language and in the
game or with delays in concrete logical reasoning, but we cannot attribute them,
without
more, to the child's visual impairment. In the case that he does not have associated deficiencies.
Clearly, the difficulties in its development will be due to --as we will analyze extensively in
the following pages-, to problems of interaction with other human beings, to the
decrease in learning opportunities, in short, to educational guidelines not
suitable, because they have not known how to interpret and optimize the "alternative routes" that
it necessarily has to use a child in the absence of vision. This does not mean, in
absolutely, that the development-learning of the blind is identical to that of children
sights, but on the contrary, there can be different routes to reach a
similar result.
Consequently, this chapter focuses on studying the peculiarities of the lack of
severe decrease in visual capacity, causes in psychological development among the
childhood and adolescence. Of course, the development of human beings does not end
in adolescence but continues throughout the individual's life. Although the
organic growth can be considered concluded at this stage, it is undeniable that to the
Throughout adulthood, the human individual continues to evolve and learn.
For our part, we have tried to provide the most comprehensive overview possible of
development between birth and adolescence, considering it in its entirety, that is
integrating the affective, communicative, cognitive, and social aspects. Without
embargo, the cognitive bias that psychological research has had in recent years
years, cannot help but be present here. Specifically, in the pages dedicated to
the school and adolescent stages have very few references to non-aspects
cognitive development.
In order to facilitate a sequence that is coherent for the reader, the chapter is
structured into four main sections that follow the classic organization - by stages
or periods - which is common in studies on development. Thus, it begins
with a section dedicated to early childhood, that is, to the stage included between the
birth and the beginnings of representational and symbolic thought, studying the
cognitive, motor, and emotional development of blind babies. The second section
it focuses on studying the genesis of images and symbols, paying special attention to
emphasis on the development of preverbal and verbal communication. Finally the
Sections 3 and 4 are dedicated, respectively, to the study of the school stage and the.
adolescence, from a predominantly cognitive perspective.

Early Childhood

Despite the importance of the first two years of life in development

psychological aspects of the blind, even today we do not have many studies on
regarding. The scarcity of works on the subject is largely due to the difficulty of
early detection of children with severe visual impairments and to the
methodological problems that arise when conducting research with
a population as scarce and heterogeneous as that of blind babies. In addition, there is
to take into account that research on subjects suffering from some
disability
they often lag behind those made with 'normal' people. For example, in
contradiction with the large number of studies that have been conducted on the
perceptual, attention and memory abilities of sighted babies, practically not
we have data (except for the controversial research by Bower, 1977, Aitken and
Bower, 1982), on how information processing is organized when the
children do not have a visual system. However - as we will see throughout this
chapter - approximately in the last 15 years a good number have been published
number of interesting contributions on different aspects related to the
early childhood of the blind, especially in relation to the development of the
social interaction and communication.

1.1. Sensorimotor intelligence

Most of the data we have on the development of intelligence in the two

the early years of the blind person's life are based on Piaget's theory (1936) about
sensorimotor intelligence. According to them, between birth and four or
In the first five months, the blind child develops similarly to a neonate.
clairvoyant. Exercise the reflexes that he is innately endowed with, such as for example,
suction, grasping, etc., except for those related to the visual system. Starting from the
In two months, he will have managed to adapt those reflexes to develop his first skills.
or customs that are centered on the infant's own body and not on the world
exterior. Thus, for example, the blind child will be able, like the seeing one, to grasp
repeatedly the sheet of her crib, and the differences between the way of taking one and
others will be scarce, since at this stage the baby's interest is more in perfecting such
a scheme that helps discover things about the object it grabs. It will also be able to
coordinate the suction and the grip, in such a way that everything will be taken to the mouth
he will take and, reciprocally, will take everything that he has in his mouth. Likewise, he will associate, as
the child seer does it, the suction scheme with the postural guides, being able to
practically recognize the breastfeeding situation, so that when I have
hunger, will only stop crying when he is in his mother's arms and placed in the
breastfeeding position.
However, it should be noted that since development does not occur only by
maturation (not even in these early stages of life), the evolution of the baby
Blind in the first four months may already be affected by lack of stimulation.
what causes vision impairment. In this sense, the only authors who have studied
the early stages of development of the blind child (Norcis, Spaulding, and Brodie, 1957;
Fraiberg, 1977), note that delays or alterations in the formation can occur
of the grasping scheme, which is so important for the optimal development of the child
blind. Fraiberg, in the observations made with a five-month-old blind baby,
he found certain alterations or delays in the development of grasping. Firstly,
the child was not able to hold both hands together at the midline of the body, as they do
the seers of that age, to explore them through vision. The thumb maintained
a primitive position, such that the baby could not maintain a
small object (a cube) with each of the hands nor, of course, pass an object
from one hand to another. Of course, we cannot consider these observations made
with a single child as defining the evolution of the perception of the blind infant and,
therefore, more research is needed on this topic. However,
it is important to emphasize the fact that in the absence of vision, the
The accommodation behaviors of the infant develop differently. In this sense
we believe it is important to train blind children in tasks of grabbing objects and
pass them from one hand to the other with the help of the adult.
But in reality, it is starting from four or five months, when the third stage begins
sensorimotor intelligence, when differences begin to be observed in the
development of a blind baby and a sighted one. The sighted one will begin in this period to
coordinate the vision and grip schemes. First of all, he will be able to look at himself
the hands when they are positioned at the midline of the body and subsequently
it will be reaching, increasingly accurately, the objects it can see. Thus, starting from
At six or seven months, especially when sitting, the baby makes a constant
exploration of objects and the position they occupy in space under visual control.
At the end of this stage, around seven or eight months, you will be able to find an object.
partially covered by a handkerchief as well as looking for the objects by the place where they
loses.
On the contrary, the blind child will only be able to explore objects by touch and will not know that
there are others than those who are in contact with their body. The only possibility that
It has an infant who cannot know that there are objects in space that it cannot see.
To embrace with arms is the perception of the sound they emit. But to the obvious problem.
that not all objects emit some kind of sound, is added the fact that the
audio-manual coordination and, consequently, the search for objects through the
sound only occurs towards the end of the first year, with a delay of six months
regarding the coordination between hand and eye (Fraiberg, 1977; Sonksen, 1979). The
primitive reflection of orientation towards sound that neonates have, is lost
subsequently even in blind babies trained to maintain it.
For the description of the development of the 'reach behavior' of sound objects in
Blind children must refer again to the work of Fraiberg. Before the age of seven.
for months there are no signs of any kind of search for the objects, so that, if
the blind baby has an object taken from his hand, he doesn't even try to get it back. Among the
seven and the eight months begins to look for the object they had previously had in the
hand, but for a very short time and without taking into account the place where it
he lost it. If the lost object is sounded, he does not try to search for it, but opens and
close your hand as if you want to grab it. At this age, there is no response to the
sound of objects that the child has not previously held in their hand. In the period
understood between eight and eleven months, the baby begins to look for an object by the
place where he lost it. When what falls is a sound object, he is able to
use sound to locate it, even though it still cannot search for an object by guiding itself
only by the auditory data, that is, if it has not been touched previously. It will be
approximately at 12 months, when blind children can search for objects
that they do not know tactilely, guiding themselves only by sound, which implies the
final coordination between the ear and the hand.
Bigelow (1986), in a longitudinal study conducted with five blind children from
between 13 and 32 months of age, obtained similar data to that of Fraiberg, although the
The search for objects using auditory guides produced something more in their subjects.
later than those studied by this author. Specifically, she only found this behavior in
four of the studied children are aged 23, 13, 32, and 15 months respectively.
Bigelow attributes this discrepancy to a greater demand for his own criteria for
positively evaluate the test (see table 4.1.), although it could also be related
with the variability that existed among these children. It is important to consider that the
subjects 2 and 3, whose study began Bigelow when they were 13 and 32 months
respectively, they were able to locate the objects by sound from the
first time they passed the test, so we don’t know exactly the age in
that they started the search for sound objects. It is also possible that the fact
that the children studied by Fraiberg were able, in general, to reach the objects
sound in earlier ages could be due to the fact that the first ones received, along with
with their parents, a well-developed intervention program by Fraiberg et al.
the so-called "Child Development Project". In any case, Bigelow's work
also offers relevant data regarding the relative importance that it has
auditory perception regarding tactile to elicit reaching behavior in infants
blind.
In all the studied children, it was found that the tests in which
they should look for an object in contact with their own body (for example, in test 1, a), that
those others in which it was about picking up a sound object, also situated
in front of the child (test 3). The sound facilitated the reaching behavior only
when the child had prior tactile contact with the object and there was no conflict
between tactile and auditory data. When the latter occurred (the object was
moved by the experimenter to a place somewhat different from the one where the child was
the younger children tended to seek it out more for the tactile data
that for the sonorous. These findings are of considerable interest, as they allow
suggest that it is the tactile keys, rather than the auditory ones, that initially lead to
blind child to locate objects in space and discover their permanence.
According to the description made by Piaget (1937) about the development of the
the permanence of objects is thanks to the constant visuomanual activity that the child
the seer carries out with the different objects of their environment and their growing ability
to move, starting from the fourth stage of the sensorimotor period (from nine
months approximately), as a world will begin to be built in which the objects
and the space that contains them is independent of their own action. Thus it will be able to
find an object that has been hidden from your sight (stage IV), later you will be able to
find that object when it is hidden in a second place as long as I can see your
displacement (stage V) and, finally, between 18 and 24 months, in the sixth and last
stage of sensorimotor intelligence, will be able to represent mentally the
objects and their movements in space (Piaget, 1937).
Given the alternative ways the blind child has to use to look for the
objects and the problems that the lack of vision generates in the knowledge of the
the same and their situation in space, we must ask ourselves not only when it is going to be
able to build a world of permanent and stable objects, but above all
how this process will take place. The authors who have studied this problem
(Fraiberg, 1977; Bigelow, 1986; Rogers and Puchalski, 1988) agree in pointing out that
blind children follow the same sequence as described by Piaget for sighted individuals,
albeit with a considerable delay, ranging from 8 to 36 months compared to these. What
it is still not too clear what the alternative routes that the blind child uses are
to know that a certain object still exists even if I cannot see or touch it. In
In this sense, according to Warren (1987), it would be necessary to study in more depth.
delve into the important theoretical problem that arises from knowing the process that leads to
blind child to construct the permanence of objects, that is, to elaborate
representations of objects and their situation in space.
Intimately related to the theoretical problem that has just been pointed out, we
we encountered serious experimental difficulties when designing the tasks that
They can assess whether objects are permanent or not for blind babies. Like the
The reader will assume, the mere translation of the Piagetian tests to the abilities.
perceptions of blind children may be far from evaluating the process
cognitive that leads these children to develop a universe of permanent objects.
We will examine later some of the tests that seem most interesting to us.
According to Fraiberg, the blind baby develops earlier - just like the sighted one - the
permanence of the social objects, specifically of the attachment figure(s), which of
the physical objects, even if the blind child does it with a certain delay. Such delay, is
It must (as has already been said) be due to the problem of having to rely solely on perception.
auditory, without the aid of the visual, to build the knowledge of the objects that do not
they are in touch with their body. Later we will study the importance they have
the social objects -the people surrounding the child and with whom they form their bonds of
attachment - not only for the development of communication and language, but also as
mediators in the knowledge of the physical world by blind children.
In his 1986 publication, Bigelow also conducts an excellent analysis of the
development of object permanence in blind children. Starting from the basis
of the classic permanence tasks designed by Piaget (1937) and standardized
by other authors (e.g. Uzgiris and Hunt, 1975) are completely based on perception
visually, this author designs a series of tests to evaluate these capabilities in the
blind children, conducting an analysis of the cognitive abilities that underlie
classic tests. It also evaluates the performance of children with these same tests
clairvoyants, whose level of development on the topic we are dealing with was known in advance
agreement with the Piagetian tests. In table 4.1, the tests with which
this author evaluates the development of reach behavior and the permanence of the
objects in blind children.
Bigelow makes an equivalence between his own tests and the stages described by
Piaget (1937) for the development of object permanence. From this
perspective, task 1, will be equivalent to those used to evaluate the third of the
Piagetian stages since sighted children between 5 and 9 months can grab a
object even if they do not see it, as long as it is in contact with their body. Test 2
evaluated the cognitive skills corresponding to the Piagetian stage IV
seers although, from our own point of view, the child did not need to have a
representation of the object to succeed in this task, as it remains in contact
with one of the sensory systems (hearing). Bigelow (1983), as well as Uzgiris and
Benson (1980) conducted a similar test with sighted children: it involved
find a sound object that the child had seen previously and that then had
hidden behind a screen from where it continued to sound. The children of the stage
III were not able to solve the task, but the ones from IV did. The tests 3, 6, and 7
they are also considered by the author we are discussing as representative of the stage
IV, although they present the same theoretical problem that was noted for test 2. These
identify the symbol and the distance at which a normal eye does so. There are also
letters that measure near visual acuity, either through the Snellen formula, or
well through a numerical scale called the Jaeger scale which uses as material
lines of text with different size types. These numerical estimates often
introducing oneself using the Anglo-Saxon units of measure or those of the metric system
decimal; sometimes they are also expressed as percentages of visual loss. The table
2.9 presents the equivalence between these different measurement systems.

FIGURE 2.4. Snellen chart for assessing visual acuity, (Goldstein, p.

167)

TABLE 2.9.- Standardized measures of visual acuity

Standard measurement system of the American Medical Association.
(Adapted from Ward, 1986 and Vaughan and Asbury, 1986)

To determine a person's visual acuity, it must be done for each eye.

separated. To calculate the percentage of visual loss, an average is usually taken among the
distant vision and near vision. In any case, it is advisable to know the visual acuity
of each eye with and without corrective lenses.
The legal definition of blindness rests on visual acuity. In Spain
to be able to affiliate with the O.N.C.E. one must have a visual loss of 80%.
better eyes and with correction. In the case of the U.S., visual acuity must be
worse than 6/60 (20/200) under the same conditions.
In any case, legal blindness does not imply that the person suffering from it is completely
blind to vision. Below this threshold, other systems are sometimes used
in terms of being able to count fingers at 3 meters (approximately equivalent to
3/60), counting fingers at 1 meter (1/60); and even below that in decreasing order
of visual efficiency, perceiving the movement of hands, locating lights in
different quadrants, and the perception but not location of light. Below this level
we can talk about absolute blindness.

FIGURE 2.5. The visual field and its measurement. (Vaughan and Asbury, p. 378)

In any case, and as we now know, visual acuity is so

only one of the parameters, although certainly the most important, that allows us
evaluate visual deficiency. We must remember that visual acuity informs us as well
only from the foveal vision and is not sensitive to other types of disorders of great importance
functional. We now refer to them.

The estimation of the visual field is also of great importance, as even a good
foveal vision ensures visual reading, a serious alteration of the field that implies
Loss of peripheral vision can affect the subject's mobility. A system
a crude way to measure vision is to place a white object of 3 mm at about 30 cm from
each eye of the subject in each of the eight meridians shown in figure 2.5
under good lighting conditions. A more accurate estimate requires making a
perimetry by a specialist. A complete field represents a function of
100% in this parameter.
The third parameter to consider for the normalized measure of vision is motility.
ocular estimated through the report that the subject makes of the diplopia they observe in
its binocular field. The estimation is made through the so-called tangent screen.
child and 45 degrees to the left. The task was considered successful if the child directed the
I reached directly for the toy and grabbed it, or if I "reached out my hand" directly in the
direction of the sound even though I couldn't grasp it.
Task 8. The child was given a silent toy. After the child had...
having started to play with him, it would be removed and would quietly situate itself inside his
reach distance in front of where it had been removed. The task was considered with
success if the child directly reached for the toy and grabbed it or directed their hand.
directly in the direction in which the toy had been placed even if it was not grabbed.
Task 9. The child was given a sound toy. After he had played with it he was
he took it off and put it in front of his chest, moving in a horizontal arc towards a
side, where it remained still. The toy continued to make noise throughout the test.
It was considered successful if the child directed their hand directly to the toy and grabbed it.
"or if I reached my hand directly towards the direction of the sound, even if I couldn't"
take it.
Task 10. A toy was sounding intermittently at two-second intervals.
and moved slowly in a horizontal arc of 180 degrees around the head of the
child. In alternative trials, the bow was made in the opposite direction. The task was
I considered it successful if, when the toy was not making noise, I directed my hand directly.
towards him and grabbed him, or if he directed his hand to where it had last sounded
toy, even though I couldn't grab it.
Task 11. A toy was sounding intermittently at intervals of two seconds.
in a stationary position within the child's reach. The task is
It was considered successful if, when the toy was not making noise, the child 'reached for it.'
directly to the toy and would grab it or if they directed their hand straight towards it, even though not
I could take it.
Source: Bigelow, A. (1986), 'The development of reaching in blind children'. British
Journal of Developmental Psychology, 4, pages 357-358.
Rogers and Puchalsky (1988) also conducted an interesting research on the
acquisition of object permanence in 20 blind and visually impaired children
aged between 4 and 25 months. Of the 20 children, 12 were totally blind and
the remaining eight had severe visual impairments; moreover, 3 of the children had
other deficiencies associated with visual ones.
The work presents at least three important innovations: 1) Firstly,
Based on the sequence of Piagetian stages, the authors design a series of tasks.
of permanence in which vision is not replaced by hearing, but by touch
(the objects that the boy had to search for were silent and he had previously had
tactile contact with them). 2) Furthermore, the relationships between the acquisition of
the permanence of physical and social objects, comparing the data obtained in the
tests of permanence with the behaviors of fear of strangers and reactions to
the separation from the mother. 3) Finally, the relationships between the
permanence of objects and symbolic play. From our point of view, there are
some methodological problems in the adaptation of Piagetian tests to the
search for tactile objects, especially concerning the prototypical behavior of the
Stage III: searching for a partially covered object. These problems, however, do not
they have interest in the work.
The results are in line with those obtained by Fraiberg and Bigelow: the
sequence of acquisition of the permanence of tactile objects in children
the blind is similar to that described by Piaget for the sighted, albeit with a delay of
between 8 and 12 months regarding these. This delay is less than that obtained by Fraiberg and
Bigelow, which seems to support the hypotheses of Bigelow and the Rogers themselves
Puchalsky: in the absence of vision, it becomes easier for the child to know that they continue
existing the objects that it has previously touched, than those with which it has only
he had auditory experience. On the other hand, it should be emphasized that in the research
what we are commenting on did not find the typical error of stage IV: displacement
visible, of the objects. When the movement followed visually is replaced by the
tactile contact with the object that is first hidden in one place 'A' and then in another
"B", there is no error that seems to be typically visual. A result that the
authors did not expect and for which they also venture no kind of explanation is
that children with visual remnants did not achieve better results than those who are totally blind
in the permanence tasks. For our part, we think that perhaps such a result may
explaining itself by the interference of tactile and visual data and by the non-nature
visual of the tasks.
In any case, it is important to take advantage of the visual remnants of children, although
set minimums, to encourage the exploration of objects and the construction of their
permanence.
In general terms, it can be said that the behaviors with which one was evaluated
mother's permanence as an object (fear of strangers and anxiety in the presence of)
separation) were found in children prior to the resolution of the tasks of
permanence of physical objects, specifically, before children could search
a hidden object (stage IV). Therefore, it seems to confirm Fraiberg's idea according to
the
blind children - like sighted ones - construct a certain representation
of an object as important as the mother prior to that of physical objects.
In this sense, and as we will see later when studying attachment, it is important to take into account
that the development of the human species has prepared newborns to attend
preferably to certain perceptual traits coming from people,
perceptual characteristics that are not only visual in nature, but also auditory
like the preference for certain acoustic patterns similar to the human voice-
olfactory, thermal, etc. Precisely those perceptual characteristics that, together,
people gather to help the child to be able to build his permanence even in absence of
the vision. Additionally, the presence of the mother (or people surrounding the child) is much
more constant than that of any object during the early stages of its development.
The authors did not find significant correlations between the level of permanence of
the objects and symbolic play, which aligns with the obtained data
by various authors (Bates, Benigni, Bretherton, Camaioni, and Volterra, 1979; Curcio,
1978), both in normal children, as well as in deaf and autistic children. We will comment further on this.
depth this last topic in the section we dedicated to representation and function
symbolic.
To conclude this analysis about the construction of the permanence of objects in
absence of vision, we will provide some conclusions. It seems clear that children
blind people can come to form a world of permanent objects and, consequently,
images of these objects through a dual tactile and auditory way. The representation
tactile seems to be easier and earlier than auditory, although both, together,
they should provide the blind person with a more complete image of the objects that also
will include, if possible, olfactory, thermal characteristics etc.. The fact that the
the construction of the permanence of objects evolves more slowly in children
blind indicates that the creation of images of the
objects and their situation in space in the absence of vision. As analyzed in
chapter 2 of this book, tactile and auditory perception have characteristics that them
are less suitable than vision for acquiring images of the world. On the other hand
part - just as happens with sighted children, the presence of the mother and of the
people surrounding the child seem to be constructed before that of physical objects. By
Lastly, it is necessary to point out that more research is needed on this topic.
that the intervention programs are based on the behavior of scope
permanence of objects.

1.2. Motor development

Most of the authors who have studied motor development in blind babies
Fraiberg (1977) and Griffin (1981) agree that the lack of vision does not have to
what alters the development of postural control. Thus, in well-stimulated blind children,
the first postural acquisitions, such as turning over, sitting, or standing up
they develop in the same way and within the same age range as in the
seers). There is, however, one exception: the posture of standing with arms up
prone position that appears in the seers about two months has only been found in
the blind from 9 months onwards. Adelson and Fraiberg (Fraiberg, op. cit.), consider that
this delay can be explained by referring to the problems that blind babies have
in all behaviors related to the start of mobility. From our point
From a behavioral perspective, it is a maladaptive behavior for a child.
blind. While such a position allows the sighted child to look at what is around them when they are
Lying in the cradle, the blind person will only get up with their hands when they are able to
to know the objects by the sound they emit, which, as we know, occurs towards
the end of the first year of life.
Precisely the few reasons that the blind boy has to be interested in the world.
outside in these early stages of life leads to a significant delay in all
behaviors related to the onset of mobility. According to Adelson and
Fraiberg these children will only start to move when they know that objects exist
outside the scope they can cover with their arms, when they have coordinated their vision
with the audition and built the permanence of objects through sound keys. Thus, the
different authors who have studied early motor development in the absence of the
vision (Norris, Spaulding and Brodie; 1957; Fraiberg, 1977; Griffin, 1981; Ferrel, 1986)
they coincide in finding significant delays in all behaviors related to
self-initiated mobility: getting up to sit down, standing up, crawling and
walking without assistance. Regarding independent walking, it occurs with a delay
about 7 or 8 months regarding the seers, even in blind children well
stimulated, without problems of postural development and without parental overprotection. In this
sense Ferrell (1985 and 1986) warns us that the fact that the child knows that
There are objects that are not in contact with their body, no. It means,
automatically, the start of your independent mobility. You need people
that surround him provide him with the necessary motivation to seek and move towards those.
objects.
Thus, a hyperprotective family anticipates the child's wishes and provides them
personal contacts and toys without the child having to do anything to find them, can lead to
that delays in mobility occur beyond what can be considered
normals in blind children.
This same author highlights the importance that body rotations can have.
that occur in early childhood when developing later a
normal and harmonic mobility. The sequence of acquisition of those rotations is the
next: first the baby would move its head from side to side, then
would be able to rotate the body from the prone position to the supine position and, shortly after, from the
supine to prone; later, from the sitting position, I could stretch my hands and
rotate the body to pick up objects located on the ground in some precursor movements
from crawling. This author asserts that, in blind children, these rotations do not occur or
they are produced with a delay, precisely because - as we have already repeatedly said,
they have difficulties in the process that leads them to know the outside world. In this
In this regard, Ferrell considers that the delay in self-initiated mobility in children
blind people as well as a possible lack of fluidity and grace in movement, is due to,
largely due to not having exercised body rotations at critical moments of
development. In his 1985 work, he proposes a series of useful situations to stimulate
curiosity and movement in the absence of vision.
In relation to the above, the problem of the lack of crawling behavior is raised in the
blind children. All the authors who have studied the early stages of the lives of these
children agree that they do not crawl spontaneously (as they do the
most of the sighted children) and it is very difficult to get them to move from
this way even when they are induced to do so with stimulation exercises. Ferrell
considers that this type of march -like the previous body rotations- are
very important behaviors for the development of posterior mobility, in such a way
that if they are not produced in due time would be the cause of permanent disorders in the
mobility throughout the individual's life. For our part, although with caution
what it forces us to not have directly investigated this topic, we think that the
Crawling behavior is not the most appropriate for a blind child, and therefore it does not work for him.
comfortable or safe. We must realize that when a blind child begins to
to move, needs to use the hands instead of the eyes to look for objects,
to recognize them and to protect oneself, which surely is not adaptive for them.
to use them for crawling. In this regard, we propose not to force the blind child to crawl,
but rather to provide her with the maximum assistance to stimulate walking in position
standing (running through corridors, walkers, etc..), which allows him to free his hands to
to know the world. We agree with Warren (1984) that the lack of crawling
In a certain period of motor development, it does not have to be the only cause of
the mobility problems that blind people may have even in adulthood. For
On the other hand, there are some sighted children who do not crawl and do not show any kind of
problems in their mobility. In this regard, Warren (op. cit.) states that there is data on
against the existence of critical periods in motor development: sighted children who
have had motor restrictions during the crawling or walking onset period,
when they regain mobility, they have no problem starting to move from
independent form; on the contrary, they do it even faster than those
that have had normal development. There are other reasons of a more general nature that
They can explain the mobility deficiencies that some blind people have.
On one hand, when blind children are under-stimulated and/or overprotected, they can
there are difficulties and delays in their overall motor development that, if not addressed,
appropriate attention will pose problems of mobility and spatial awareness
even in adult life. On the other hand, it should be noted that the lack of "grace and
"looseness" in the march may also be due to the limited possibility that they have
blind to learning, by imitation, the way of moving of the individuals of our
society.
Consequently, we believe that blind children should receive during the first
years of their life, appropriate programs to stimulate their general motor development,
putting aside the rigid notion of critical period.
We cannot conclude this section without reflecting on the guidelines of
motor development that can be considered normal for children who have
severe visual difficulties. We consider the sequence established by Fraiberg and
subsequently corroborated by the majority of the authors who have dealt with the subject,
it can be taken as a reference when it comes to evaluating and stimulating development
motor skills of blind children. Consequently, the existence of a certain delay in the
the beginning of mobility by these children must be considered as the
normal consequence of the
problems posed by the lack of vision in understanding the outside world. This
lack of knowledge that people and objects exist when they are not in contact
with the child, it causes him to lack motivation to start moving. Thus, it is
It is necessary to maximize the motor skills of the blind child in the first
childhood, but always within their own zone of proximal motor development, having
keep in mind that you must use alternative pathways instead of sight and, therefore,
fleeing from naive comparisons that take evolutionary patterns as a norm
of the sighted children.

Attachment and interaction

We all know the importance of emotional relationships and interaction in the

development of the human being, but in the case of children who have some type of
deficiency, in our case blindness, such relationships will have -if applicable- a
Greater importance. Affective and social relationships begin with the bond that
establishes the baby with its mother (or with the person or persons responsible for its care),
what has been called 'attachment' (Bowlby, 1969). Attachment is not formed, like
initially behaviorist psychologists believed, through associative learning, that is to say,
because the child associates with the mother the satisfaction of primary needs
food, heat, and hygiene. In contrast, as has been pointed out by the
Bowlby's research deals with a bond that is in itself of a nature.
primary. Both the baby and the mother (and adults in general) have some
systems of prefigured behaviors that tend to the child-adult interaction and that will provide
place a relationship of attachment if the conditions are met in both elements of the dyad.
suitable for that interaction. The infant has a set of
behaviors that tend to interact with other human beings that soon
they will be converted into the behaviors referred to by Trevarthen (1989) as "intersubjectivity"
primary." Thus, it has different reflex behaviors that seek physical contact,
like sucking, grasping, or the Moro reflex. It also has a behavior
perceptive that shows a tendency to pay attention to social stimuli, such as
fixation of gaze on the faces of the people who care for him, preference for
acoustic patterns similar to the human voice, by moving figures, etc..
In addition, it is capable of emitting social communication signals such as the same gaze,
the smile and the cry as well as imitating mouth movements. These behaviors are, to
principle, of reflective character or
predefined, but little by little they will become intentional, as long as they receive
appropriate attention and response from the people around you. All of these
behavioral patterns of babies, they interact synchronously with others
behavior systems that adults in general and the mother in particular put into
marches when they relate to young children: tendency to establish contact
corporal with the baby, to maintain eye contact with him, to surround the situations of
breastfeeding and hygiene with manifestations of affection, as well as to maintain a
appropriate gestural and verbal language for the child. Thus, the interaction between the systems of
the behavior of the mother and the baby will lead to the fact that between seven and eight months, the baby will have
the emotional bond we call 'attachment' is formed, which will manifest in the child
perfectly recognizes its attachment figure, showing feelings of unity and
preference towards that person, as well as in the child having certain expectations.
regarding the person to whom they have been linked.
It is important to highlight that the fact that we are talking about a primary bond
does not mean, in any way, that the attachment relationship between the child and the mother (or
person(s) responsible for their care) is genetically programmed and is formed
regardless of the suitability of the relationship that occurs between both.
On the contrary, attachment is the result of an interactive process that, in its early stages,
is guided by the adult. As we will see next, in case the adult does not
interact with the child appropriately during the first months of life
will necessarily cause problems in the emotional and social development of the baby and, in
consequence, in the formation of the so-called "secondary intersubjectivity" (Trevarthen,
1989), with important consequences for the formation of the symbolic world.
We briefly outline the normal genesis of attachment, in order to explain to the
Reader the problems that may arise in this area for a blind child. From the
from birth to 2 or 3 months the baby shows preferences towards the members of
its own species (looks, smiles, and babbles preferably when encountering
perceptual stimuli that come from people), but it does not establish differences
among these, and their responses, like the smile, are not yet of a social nature. Among the
At three and six months of age, the child increasingly discriminates against their attachment figure.
and it is her to whom he directs his looks, smiles, tears, etc., although he still does not reject
the unknown. Approximately from 7 months old, babies have
clearer preferences for their mother (or another attachment figure) and reject people
strange. This is the stage in which most children have responses
negativity, in front of unknown people and known as 'fear of the
strangers." Negative responses are even greater when the mother disappears and leaves
the child with some unknown person. According to Schaffer and Emerson (1964),
This type of phenomenon occurs in 70% of children from the period.
understood between the ages of 8 and 10 or 11 months.
When a baby is born without having such an important sensory system for the
interaction and communication in the early stages of life such as vision,
problems can arise in the manifestations of 'primary intersubjectivity',
as well as in the development of communication and intentional interaction. It is very
It is important to note that such problems do not directly arise from blindness, as
As will be seen below, blind babies have a good repertoire of
prefigured behaviors and alternative ways to relate to adults. They are
precisely those adults - the people surrounding the blind child - those who can alter
his behavior towards the baby due to the baby's blindness. On one hand, the
the birth of a blind child can cause emotional trauma for the parents, to the
it is difficult to accept your child's problem and interact normally with him, since the
expectations that are usually held regarding the development of a blind child are low. Furthermore,
these expectations are confirmed by how difficult it is for a clairvoyant
establish interaction with a baby when their gaze is absent and when their face lacks
common expressions, since the gaze and facial expressiveness are one of the
the most important preconfigured behaviors in the human species when it comes to eliciting
maternal-type behaviors. Consequently, what can be altered are the
adult behavior systems that, as we have said, are those that, in a more or
less intentional, guide the interaction in the stages prior to the formation of
link. Thus, in many cases, the parents of the blind baby mainly take care of
of the child's physical needs, food, hygiene, etc., without knowing how to interpret their
primary interaction behaviors and neglect the affective and communication aspects
and socialization. In addition, it is important to consider that blind children, being unaware of
existence of the world that cannot be encompassed with their body, tend to be calmer and
demand less attention than sighted people. Consequently, it may happen that
that the blind child experiences significant emotional deprivation, has problems
to develop a good attachment bond, and even develop stereotypies and others
symptoms similar to those of autistic children, occurring problems in genesis
of the symbolic world and, consequently, in the development of language. We do not want
to say, far from it, that all these manifestations are a direct effect and
necessary for the child's visual impairment, but a consequence of the possible
existence of a serious alteration in affective communication. To avoid all this
we believe it is absolutely necessary for parents to receive, as soon as possible once
once blindness is diagnosed, education and support programs in which they obtain
information about the prefigured behaviors alternative to the view that is available
blind child to interact with the people around him from the early stages of
his life.
The authors who have studied attachment in blind children (Freedman, 1964; Fraiberg,
1977; Rogers and Puchalsky, 1986), indicate to us that if the proper synchronization is established
between the child and the person/people responsible for their care, they evolve following certain
stages similar to those of psychics, although the paths they use in that genesis may be
different. Thus, and more or less in the same age range as these, the blind children
they also develop a social smile and show signs of having "fear of the
strange.
Newborns have a reflex behavior that relaxes the facial muscles.
which is often interpreted by adults as a smile and which, precisely for that reason,
it will end up becoming a social smile. In the case of the blind child, the voice is the
substitute principal of the human face when it comes to eliciting smiles. In the 10 children
studied by Fraiberg (op. cit.), already in the fourth week of life examples were found
of selective, although irregular, smile to the voice of the mother and the father; the voices
strangers, on the contrary, did not provoke this behavior. From the third month, when
the clairvoyant boy smiles regularly at the sight of the human face, the blind one does.
more frequently - but not always - when he hears his mother's voice and that of others
known people. However, tactile stimuli such as tickling, swaying
y
Caresses do regularly provoke the child's smile. Also Rogers and Puchalsky.
(1986) found that all the blind children studied by them showed
smile when they were visited for the first time at the age of 4 months.
Between 6 and 11 months, the child with normal vision smiles.
selectively to her mother and acquaintances. However, the smile of the
blind children seem not to evolve during this period, as production continues.
irregular form before the voice of the mother and other relatives. Both Freedman and
Rogers and Puchalsky observed that a decrease in smiling occurs in children.
blind individuals between 8 or 9 months of age. While the first author attributes such
descent into lack of visual stimulation, Rogers and Puchalsky (op. cit.) interpret it as
a manifestation of 'fear of strangers' in the presence of one's own
investigators at the family home recording with a video camera the
interactions between the mother and the child. For these authors, there are other stimuli not
visual -the voice and tactile and kinesthetic stimulation- that provoke a smile in the
blind children, as evidenced by the fact that, in their own research, the
the frequency of this behavior increases during the first year of life, except in the
period between 8 and 9 months.
We cannot fail to point out the existence of a prototypical behavior of children.
blind people that highlights the existence of an alternative pathway to vision for the
recognition of people's faces. Precisely at the same ages as the
seeing children smile primarily at their parents' faces, a little before they
develop the phenomenon of 'fear of strangers', the blind, in a completely
spontaneously use their hands to explore the faces of their relatives. Fraiberg
he observed that the tactile seeking behavior began casually from the
first month of life, but starting at five months it became increasingly more
discriminatory and intentional. Precisely between 5 and 8 months of age, the 10
children studied by the author carefully explored the faces of their hands
closest relatives, when they held them in their arms. On the contrary,
these same children only briefly explored the faces of strangers (among them
the author of the work herself), which suggests that they could clearly differentiate the
faces of known people and those of strangers. Thus, we can say, following ...
the same author, that there is a correspondence between the guidelines of tactile exploration
the faces that blind children develop and the behaviors of discrimination and
recognition that appears in the seeing child approximately halfway through
first year. Furthermore, from our own point of view, there is the possibility that
this behavior may have a functional value equivalent to that of a smile, in what it
it refers to maintaining interaction with the child's preferred people.
However, for Fraiberg, there would be an important difference between the smile of
the blind children and that of the sighted ones which should be analyzed carefully, due to the
repercussions that it may have when provoking child/adult interaction.
according to this author, in the absence of vision, children do not seem to smile in a way
spontaneous to initiate social contact, as psychics do, on the contrary their
smile always has a reactive character, as it is only produced in response to the
interaction initiated by the adult. Certainly, a first comparison of the attitude
between a sighted child and a blind one among the people around them can make one think
that the smile of the first initiates social contact, while that of the second only does it
it continues once it has occurred. However, when we analyze, just as it
Rogers and Puchalsky (n.d.), the possibilities that blind and sighted children have
to perceive people who are not in touch with their bodies, we find that,
possibly, both behaviors are reactive. Specifically, the sighted child does not smile
in the void, but as a response to the smile or the simple sight of his mother and
other known people. Likewise, blind children respond with smiles
when they hear their parents' voices or when these engage in some game with them that
involves physical contact. Therefore, we can assert that in both cases it is a
responsive smile: sighted children respond to the visual stimulus that is the face
Humans, blind children respond to tactile and auditory stimuli that announce the
presence or proximity of their parents.
In relation to the above, we consider it very important that the child's parents
Blind people should know that the smile of their baby has the same social meaning as that of a
seer, even if it occurs as a response to a different type of stimulation. In this
In this sense, another result of the study by Rogers and Puchalsky is of great importance,
according to which the smile of blind children was always followed (in the
100% of the cases), due to some kind of social behavior by the parents. This
it means that, in the absence of vision, the smile serves to continue and maintain the
social interaction, in such a way that the smile patterns of the blind and the sighted result in
more similar than Fraiberg et al. (n.d.) had assumed.
Regarding the negative reactions of blind children towards people
unknown, Fraiberg's study is our only source of data. This author
he observed that this type of reactions began to manifest between 7 and 15 months
of age in 9 out of the 10 studied blind children. The behaviors of 'fear of the
strange ones" occurred naturally during the observation periods and also
They were induced by Fraiberg and her collaborators experimentally.
In the period before six months, blind children - just like the
seers show their discomfort at minimal changes in posture when they
they find themselves in the arms of unknown people. Subsequently, between 7 and 15 months,
Negative responses to physical contact with people are clearly occurring.
relatives (even if they are not completely unknown to the baby). So when a
the stranger takes the child in his arms, he resists, tries to pull away, cries, etc... From
According to Fraiberg, avoidance behaviors are somewhat different in the blind than in
the seers, since in the absence of vision, the children do not seem to have answers
faces of displeasure. However, both the blind and the sighted manifest of
vocal and motor forms of rejection through protests, cries, screams, resistance to
physical contact and
active search of the mother.
According to the same author, it is tactile stimulation, more than auditory, that
provokes the fear of blind children towards strangers. Only one of the children from his
the study showed avoidance behaviors in response to an unknown voice, although
they all seemed to pay attention to this type of voices, stopping their activity and their own
vocalizations. As mentioned before, the decrease in babies' smiles
blind between 8 and 9 months of age observed both by Fraiberg and by Rogers and
Puchalsky can also be interpreted as a reaction to the sound of voices.
unknown. In summary, without losing sight of the importance of tactile stimulation
it has for blind children, we think that their manifestations before strangers are
quite similar to those of psychics. These children also do not produce responses
avoidance clues at the mere sight of unknown people, but rather when
they try to have a greater contact with the baby, for example, to hold him/her in
arms. The reactions previously mentioned become more intense in children
sightings when the mother leaves them alone in the presence of people who are not familiar to them
family members, reactions referred to as 'separation anxiety'.
Does the blind child behave the same way as the sighted one in the face of separation?
of their attachment figure? Research conducted with sighted children indicates
that they show their discomfort when the mother leaves them alone, going out of a
room -even if strange people are not found in the same place-, in the period
understood between 6 and 8 months. In the case of blind children, Fraiberg informs us that
what type of reactions occur, on average, between 11 and 12 months, when the
the child is not in physical contact with the mother. On the contrary, when the march of the
mother is produced at the moment she plays and maintains contact with her child, she
they produce clear protest responses, virtually in the same age range as
in sighted children. The knowledge we already have about development of
the permanence of tactile and sound objects in blind children allows us to
provide a clear explanation for their reactions to the separation. Obviously,
when the visual sense that allows maintaining the perception of people is missing
they are found at a certain distance, the child only knows of their existence when they are maintained
physical contact with him or when he can hear his voice. We also know that for the child
the visually impaired find it easier to locate objects and people through tactile data than
by the auditory ones. Consequently, it is natural that the protests against the separation of the
mother occurs, first when she breaks physical contact with the child and some
months later also when he stops hearing her voice.
Let's now examine the problems that separations pose for blind children.
prolonged issues with their mother or attachment figure and their possible solutions. The
effects that this type of separation can have on physical and psychological development
Human babies have been studied by various authors, such as Spitz.
(1965) and Bowlby (1973 and 1980). In the case of blind children, these consequences
they can still be more serious, since they depend even more than the sighted on the
interpersonal relationships to know the world. Moreover, it is important to consider that
these children often suffer from hospitalization periods more frequently than those
normal due to vision problems (or the disease that has caused it)
caused). Fraiberg (op. cit.) cites cases of brief and prolonged separations that,
In any case, they caused disturbances in the normal development of the blind child. Upon reaching
At this point, it is important to note the convenience of the blind child - just like the
clairvoyant - have more than one attachment figure. The work done with clairvoyants
they make it clear that children can emotionally bond with more than one
person (e.g., the father and the caregiver in addition to the mother), even if they have preference
for one in particular, which is usually the mother (Parke et al., 1981). In the
in the case of blind children, having more than one emotional bond can be very
beneficial, as this way a second person can replace the mother, at least
temporarily, in the event that it is not available for the child.
In summary, we can conclude that, even in the absence of a sensory system such
As important as vision is, the human newborn has a good number of
alternative prefigured behaviors that tend towards interaction and formation of
affectionate bonds with the adults of their species. If these adults are capable of
interpret the alternative ways available to the blind child to relate to them
and, consequently, in reacting to their demands, they will form their emotional ties of
in a way similar to how a clairvoyant does. However, we must abandon
our 'visuocentrist' positions and understand that precisely the systems
sensory substitutes that the blind child uses to know the world, especially
the touch and the hearing condition their manifestations towards people. Thus we cannot
expect that the smile of the blind child or his reactions to strangers are analogous to
those of the seer and that occur under the same circumstances, even if they are
functionally equivalent. Due to the problems posed by the construction of the
persistence of objects -in this case social- through sound,
It is the tactile exchanges that initially seem to dominate interactions.
both from the child and the adult. Thus, the blind child will smile in response to the
tactile stimulation of the adult, and -in what seems to be a marvel of adaptation- will use
his hands to recognize the face of his relatives and also as a way to maintain
the attention of these, along with the smile. As for auditory interaction,
we think that the first responses of blind babies to human voices
they can be interpreted in light of the work done by Eimas (for example,
1985) with sighted newborns. The sighted newborns (and logically also the non-
psychics) have clear and differentiated responses to the sound of the human voice. It is logical,
Therefore, blind children learn to distinguish between familiar voices very early.
and unknowns. It is more complicated for us to explain why the sound of voices
relatives do not always evoke a smile from the blind baby. Although, without a doubt, it does.
new research on this topic is needed, we assume it is due to the
problems that the blind child has until the end of the first year, to know that the
objects (and surely also people) continue to exist when contact is lacking
physical.
In this regard, we consider it absolutely essential that the parents of the babies
blind individuals receive instruction on the abilities their children have to
to relate and to establish emotional bonds with them. The importance that for the
Human species have the first exchanges of glances between the baby and its mother.
it can make adults insensitive to other possible systems of interaction such as,
example, tactile exchanges and vocalizations. The adults in charge of
care of a blind child must know that he also has, from birth, a
a good number of behaviors that show empathy towards other human beings and that
has mechanisms to express it. It is important for them to know that a child
the visually impaired also smile and have mechanisms to differentiate people
relatives of the strangers, as well as to express their affection for their figure or figures of
attachment. We cannot deny that, often, when we read some of the research
conducted with blind children, or when we rely on informal data from people
who work with them on a daily basis, we find a good number of cases where
which of these children have more or less serious problems in the call by Trevarthen
"secondary intersubjectivity," which manifests mainly in difficulties in the
development of symbolic function (mainly play and language), and in existence
of stereotypes. For our part, we think that these autistic-like symptoms do not
are inherent to the
blindness, but to the difficulties that this causes when it comes to provoking the
"maternal" behaviors of adults. Thus, the significance they have for the
human beings visual exchanges from the early stages of life, can provide
place where the parents of the blind child are "blind" when it comes to interpreting
the alternative ways that it has to develop love and interaction with the
human beings. We will continue to analyze these problems in the next section, when
let's study the data we have on the development of the symbolic function in the
blind children.

2. Representation, interaction and symbolic function: communication, language and

fiction game

In the psychological literature on the development of the visually impaired, there is none, as far as we know,
no work that directly addresses the issue of the genesis of representation and
the symbolization in the absence of the visual system, probably due to
problematic and complex that results. Additionally, the research conducted on this
themes with sighted children are quite recent and, as the reader knows, those referring to
blind children often lag behind them. However, fortunately, throughout
In the last 10 years, a good number of works have been published that address
this theme in a more or less indirect way. Thus, as seen in the previous section,
Along with the already classic work by Fraiberg (1977), we have two other publications.
recent developments in the representation of objects in children with
severe visual deficiencies. On the contrary, we know very little about the development of
the guidelines for imitation in the absence of vision, with the exception of some data about
imitation of vocal and verbal sounds.
Regarding the development of symbolic function, most of the research
Recently published studies have examined the development of communication and language.
in the absence of the visual system. As we will see throughout this section, we have
the present with a good number of works -some of them excellent- on the
guidelines that characterize preverbal and verbal communication between blind children and their
parents, as well as on the characteristics of vocabulary acquisition and in the absence of the
vision. On the contrary, and despite its importance when studying the genesis of
the symbols when the visual system is absent, few authors have studied the development and
the characteristics of the symbols used by blind children in the
fiction game. "
We cannot continue this section without explaining, in some way, what we understand
by representation and by symbolic function. Thus, without intending to delve too deeply
on this complex topic, for which there are excellent works published in the language
Castilian (Riviere, 1984 and 1990), we will try to summarize the position below
theoretical framework on which our organization of research on the origin of
images and symbols in blind children.
According to Piaget's theory of development (Piaget, 1946), the child begins to
jointly manifest certain representative and symbolic capabilities,
approximately in the second half of the first year, when the period ends
referred to as "sensorimotor intelligence". According to this author, we can say that a
a child has begun to develop such skills when he is able to differentiate between
signifiers and meanings, that is to say using a signifier (an image, a symbol
or a sign) to refer to a meaning that is not present and that, consequently,
is 're-presented'. Both the significants and the meanings of the symbols are
they originate from the adaptive action that the baby performs with objects from the early
stages of life. Specifically, the significants would have their origin in the action
accommodative -the imitation- that the child performs both of the objects themselves as
of the activity carried out with them. That imitation in the fourth and fifth stages of
sensorimotor period, can only be carried out when the model is present for the
child; on the contrary, in the sixth stage, more or less between 18 and 24 months, the child
begins to imitate absent models and to be able to internalize such imitations using
mental images. Meanings, on the contrary, derive from the assimilation that the
the baby itself creates reality, since giving meaning implies, for Piaget, assimilating that
reality to the action schemes of the subject. Within this theoretical model, the example
The clearest example of meaning formation through assimilation would be symbolic play,
in which the child distorts the reality around him by assimilating it to his own schemas.
The signifiers and the signifieds develop together and coordinate with each other to give
place to symbols. Thus, for Piaget and his collaborators, representation and
symbolization and terms are practically synonymous and their acquisition by part of the
children manifests both in the ability they have to evoke through
images of objects and situations that are not present, as in the use of symbols
in the fictional game, and in the use of conventional linguistic signs.
Research conducted in recent years on both normal children and those...
who suffer from different types of disabilities or deficiencies (Riviere, 1984), thus
how our hypotheses about the cognitive development of the blind make us be
more in line with interactionist theories about the origin of symbols than
they start from the theories of Vygotsky and Bruner. Thus, we agree with the theory of
Piaget in that the representations of objects and the space in which they are situated,
the ability to evoke them when they are not present arises from action
sensorimotor that the child carries out on them, specifically in the mechanisms
accommodative involved in imitation. However, the ability to communicate
with other human beings, first about objects and situations that are present (in
the period of sensorimotor intelligence), and subsequently about those that do not
they are present but rather "represented", what we call symbolic function, does not arise from
the actions that the child performs in isolation with the objects, but rather the interactions
that the baby and the adult carry out together in relation to these objects.
The origin of symbols lies in communicative interactions, first reflective and
later intentional, that the baby establishes with its attachment figure from the early
stages of life. Before we can say that the child uses "symbols", already in the
the last quarter of the first year develops intentional forms of communication that
they have a presymbolic character. It is at this moment when the child, in addition to
to take an interest separately in objects and in people, begins to show its
intention to communicate with people about the characteristics of objects,
share with them their interest in these, in a process that has been called
"triangulation". Thus, approximately at the end of the first year, children begin to
use pointing signs, as well as exchanges and vocalizations of type
"protodeclarative", to share their interests about the world with other people.
that surrounds them.
It also uses the same mechanisms to achieve something through people.
what is considered a 'protoimperative' function. But it is still necessary that
the objects or situations that the child refers to are present. According to
Riviere, it is necessary for the child to develop certain representational abilities so that
may use symbols, as he believes that symbols are 'representations of
representations." We can talk about symbols when the child represents their own
image or concept of an object through a gesture or a word with the purpose of
to communicate with someone. 'The child represents the dog (or rather his concept of it)'
when it says 'wow'... Based on its language or its actions, it represents its schemes or
concepts" (Riviere, 1990, p. 115). Thus, only at the end of the second year of life, once
Once the representative capacity is acquired, the child will be able to use declarative forms.
and imperatives to communicate and ask others for objects or situations that are not present
presents, using conventional symbols or signs.
The first communicative attempts of children only acquire meaning when
they are interpreted by an adult based on a context. As already mentioned in the
section corresponding to 'attachment', the mothers -or caregivers of the
children tend to interpret and give meaning to the interaction behaviors of babies,
even when they are of a primary or reflective nature. Subsequently, the first ones
intentional presymbolic communicative behaviors are also interpreted by
the mother according to the context in which they take place. So when, for example,
a child of approximately one year of age in a certain situation points with the
a bear's finger while vocalizing, his mother is able to interpret if he wants to achieve.
the object to play with or wants to "tell him something" about the little bear, acting accordingly and
‘translating’ with their own gestures and verbalizations the child’s intentions. More
In the afternoon, when after 18 months, the child is capable of representing objects.
absent and tries to communicate about them using symbols and signs, the mother
continues his work of interpretation. When, for example, the child at one moment
determined, he starts to crawl and say "wow" pointing with his finger at the street to
through the window, the adult who is with him interprets these symbolic behaviors
as the child's intentions to share with him his memory about a certain
dog that I had previously seen on the street. From that interpretation, it will continue
"the conversation" with the child verbally translating his intentions and
informing him - in an appropriate language - of his own impressions about the puppy.
Consequently, we can say that the symbolic function is born and develops in the
social interaction; but also, thanks to it, the child will be able to incorporate everything
the system of symbols that your society, your culture provides you. Thus, in the game of
fiction the child dramatizes through symbols and out of context the uses and customs
of the society in which he lives, as is evident in the prototypical games of
the children of our culture: "the little houses", "the schools", "the wars", etc. For their
part, the use of language makes the child incorporate the tools or
symbolic instruments created by their own culture and that they use not only for
to communicate with other human beings, but also to communicate with oneself
same through the internalized language that consists of thought.
At this point, it is necessary to revisit our main interest: the development of the
representative and symbolic capacities in blind children. We believe that for these
children, interaction with adults is even more necessary and important than for the
seers. Given the restriction that the lack of vision imposes on knowledge of the
objects that are outside of the space that the child can grasp with their hands, the paper
"triangulator" of the mother must also have the function of awakening the interest of
child for those objects. Thus, from our point of view, in the case of blind children, it is
it is necessary for the attachment figure to awaken the child's interest to act on the
objects, since knowledge of the surrounding world is a necessary and prior step
so that I can later establish communication guidelines about those objects
with people. We think that in the case of blind children, perhaps even more
that in the seers, the adults with whom the first relationships are established
Affective factors fulfill the function of 'mediating' the child's relationship with the objects of the world.
physical. In this sense, the people surrounding the blind child - especially his mother - have
to provide them from the earliest stages of their life the greatest number possible of
experiences that allow him to know and manipulate objects, as it is the activity
sensorimotor that the child performs with these, which, through imitation, will cause that
the child can imagine such objects when they are not present. We will discuss more
the role that interpersonal relationships can have in the development of
representative capabilities of blind children.
It is also necessary to point out that, in the absence of such an important system as it is the
vision for the establishment of pre-verbal communication guidelines, the task of
The interpretation of the mother of the blind child may perhaps be greater than that of the child.
seer. As we already pointed out in the section regarding attachment, and as
we will see when analyzing the different existing research on the characteristics of the
preverbal communication between blind children and their mothers, they must set aside
the 'visuocentrism' that characterizes human adults and adapts to interpret
the peculiarities of the communicative attempts of children who cannot
use the
visual system.
The following sections analyze the research related to genesis.
of the images and symbols in children with severe visual impairments. Thus,
we will present to the reader the few data we have about imitation,
we will resume the investigations already presented on the development of permanence of
the objects and we will analyze in depth the works that exist in the bibliography
about the characteristics of preverbal and verbal communication, as well as those related to
symbolic play in blind children.

2.1. The beginnings of representative capacities

When addressing the issue of children's access to figurative representation
we must necessarily resume the publications on the acquisition of the
permanence of objects, as they constitute our only source of
information about the genesis of the first images in the absence of vision. Thus, the
data we have on the development of representational capabilities in the
blind children are based on Piagetian theory. As the reader knows, this type of
work is based on the idea that when a child, at a certain stage of their
development, is capable of searching for an object that is not in contact with any of its
sensory systems - that is, when you cannot see it, touch it, hear it, etc. - the same
the fact that I tried to search for it can be considered an indicator that it has an image
mental, a "representation" of that object.
Also, most of the research conducted until approximately the
late 1970s, on the genesis of representation in sighted children
they have been based on the mentioned evolutionary theory. Subsequently, the great advances
carried out in the understanding of babies' early abilities to perceive,
process and remember the information coming from the different sensory systems, have
led many researchers to propose the idea that children have certain
representative capabilities -especially in relation to social stimuli- a lot
earlier than Piaget and his collaborators thought. For example, from the age of 5 or 6
By the months, children are able to distinguish familiar faces and voices from those that are not.
The sounds are strange, which involves comparing the faces or voices that at one moment
determined are perceiving with other absents that it remembers and that, consequently,
somehow has 're-presented'. Of course, we will not go into this here.
exciting topic that undoubtedly goes beyond the objectives of this chapter. The reader
interested parties can refer, among other reviews conducted in Spanish, to the articles of
Palacios (1984) and Riviere (1984). Unfortunately, nothing has been written about these.
initial representative abilities in blind babies although yes, for example,
we reflect on the research we analyzed in the section dedicated to
development of attachment in these children, we thought it could be logical to attribute to them certain
early representation capabilities of stimuli, evidently of a non-character.
visual (tactile, olfactory, auditory, etc.), especially those related to perception
of the people.
Research on the acquisition of object permanence, which is
they analyzed in the section corresponding to sensorimotor intelligence, they state that
I affirm that blind children are also able to "represent" objects.
perceived tactilely and audibly, although with a delay of between 8 and 32 months when
compares them with the seers. This delay is less when the images originate in
the tactile exploration of the object that is used when trying to identify it through the data
auditory. Consequently, we can assert that for blind children it is more
simple
develop tactile images of objects when compared to auditory ones,
although it would be necessary to conduct new research on representations of
multimodal character since, possibly, blind children - like sighted ones -,
they would easily build representations of physical and social objects when they can
count on data from various sensory modalities. On the other hand, the
the data we have about the fear of strangers behavior seems to demonstrate that
blind children begin to have a certain representation of the mother, which
it probably has a multimodal character, starting from the second half of the first
year. In summary, we can say that it is possible to access a figurative representation.
of the objects and of the
people starting from a non-visual sensory-motor activity. Therefore, the
blind children also develop mental images that, according to the
investigations by Fraiberg, Bigelow and Rogers and Puchalsky, cited in section 2.3.
are predominantly of a tactile and auditory nature, although, without a doubt, also
The olfactory, kinesthetic, and thermal types are important.
On the other hand, as has already been said, the tests used in the investigations of
Piagetian characteristics always leave some doubts about their validity.
to be used with blind children. We believe that 'translation' - whether of a literal nature or
more free - to the tactile and auditory modalities of tasks that, like those of
the permanence of objects is primarily based on the visual modality not us
they provide sufficient information about the alternative routes used by children
blind in their access to figurative representation, as well as about the problems they face
it proposes the use of those non-visual pathways. It is necessary, therefore, that they
conduct more research on this important topic.
Certainly, the problems that blind children face in accessing objects that
they are outside their immediate environment, as well as the fact that the search for the
objects by sound occur later than visual search, cause these
children develop after the seers the images of those objects. As has already been seen
previously, there is a great variability in the data provided to us by the
different authors on the duration of that time interval, which depends on both
factors related to the experimental designs used by researchers, such as 'of
the characteristics of the children themselves studied. Thus it can be considered that it
it depends on whether the tests are conducted in tactile or auditory mode, on the level
of demand
regarding the responses of the children, or the age of the children when they are
studied for the first time. It also depends on the characteristics of the children
studied, that is to say of variables such as the etiology of blindness, the stimulation
they have received since their birth, etc... In any case, putting aside the
exact amount of the difference in the age of acquisition of the first images,
it certainly proves costly for children to reconstruct the images of objects and of their
situation in space in the absence of visual sense. From our point of view, at
even though both touch and hearing, as well as the other sensory systems that
a blind child is allowed to have figurative representations, the lack
vision poses important problems for the construction of these representations.
Therefore, it is possible that a blind child has fewer images than one
seer of her own age, and who knows and recognizes fewer objects than
this. Furthermore, in the absence of visual perception, the creation of images of the
Objects and their situation in space is more costly. As analyzed in chapter 3.
from this book, the characteristics of the substitute sensory systems that should be used
the boy
When they cannot see, they can explain their problems in figurative representation.
Think of the reader, for example, how slow and costly it must be for a blind child.
elaborate the image of a large table when it has to be perceived slowly and
successively with touch, or its difficulty in elaborating representations of objects that
it cannot perceive in its entirety but only in a fragmentary and sequential manner, like the
buildings or cars. Likewise, as we will see in chapter 5, the use of systems
sensory substitutes for vision (such as movement, proprioception, etc...) make
that for the blind child it is truly costly, although undoubtedly possible, the development of
spatial images, first of their own home, and then from other places such as the
school, the park, or their own city.
For all of this, from the beginnings of representative thought we find what will
to be a constant characteristic in the development and learning of blind people: the
problems in access and processing of figurative representation.
These problems arise from having to use sensory systems that, like
touch, proprioception, or hearing are less effective than visual in gathering and
information processing.

2.2. Imitation

Despite the importance that imitation has for the genesis of images
mental and to form the basis for the development of fiction games, does not exist in the
literature no work that directly addresses the issue of early development of
these abilities in blind children, probably due to the idea that the
imitative capacities of babies can only develop through the system
visual. However, the imitations that children make - even those who can see - are not only
they have a visual character (although these are likely the most initially
important and, above all, those that attract the most attention from adults), but rather
they can also arise through other sensory modalities. Thus, children
they make tactile-kinesthetic type imitations when they engage in rhythm games and
movement with adults, and they are also able to imitate sounds and
vocalizations both non-verbal and verbal. Therefore, we can practically do nothing
to talk about the development of the abilities of the blind to imitate in the presence of
model during the period of sensorimotor intelligence. However, the
research conducted by Junefelt (1987) and Preisler (1991) provides us with,
indirect form, some evidence of the existence of imitation behaviors by the
blind child. It is about the imitation of body gestures and typical rhythmic movements.
children's songs, in pre-verbal communicative contexts of turn-taking.
We believe that it would be these types of imitations, along with the auditory-vocal ones, that
they should be investigated in blind babies, at the corresponding ages to the
sensorimotor intelligence.
We have more information about the ability of blind children to imitate.
vocalizations and verbalizations. Certain authors, such as Fraiberg (1977), affirm that
these children are not capable of imitating adult vocalizations until after they have
upon completing their first year of life; others, like Rowland (1983), point out that they
they produce high proportions of vocalizations by blind children between the ages of 11
and the 16 months. For their part, both Junefelt (1987) and Preisler (1991) also
they found that the blind children studied by them responded to interactions with their
visionary mothers imitating vocalizations or extravocal sounds of different tones.
Some researchers have studied the importance that the lack of can have.
visual imitation in early phonological development. Mills (1983, 1988) studied the
production of phonemes that have a visually observable articulation in
German language (labials and labio-dentals) and those that do not have them (velar sounds)
palatal, dental and guttural), in blind and sighted children aged
between 1.0 and 2.21 years. Their results show that the seers were more accurate in
the articulation of the visible articulation phonemes, with 79% correct phonemes,
that in those with invisible articulation (49% correct). On the contrary, as it was of
wait, did not find significant differences between the production of these two types of
phonemes in blind children, who correctly produced 59% of phonemes
observables and 48% of the non-observable ones. On the other hand, when analyzing the phonemes
substitutes that children used when making mistakes, this same author found that the
sightless individuals rarely substituted one phoneme for another of a different visual category, for
for example, they did not produce n instead of m, but rather substituted the m for another type of sound.
labial. On the contrary, blind children did make mistakes that consisted of replacing
a phoneme for another corresponding to a different visual category.
Mulford, in a study conducted in 1988 with English-speaking children, demonstrated
that the first lexicon of sighted and blind children was different regarding place
articulation dominant. While the first elements of the lexicon that were emitted
the blind children were primarily composed of palatal phonemes and
dental (of non-observable articulation), the sighted used more words of type
labial (observables).
Despite the peculiarities found in the emission of sounds by
blind children, both Mills and Mulford agree that their development
phonological can be considered normal and that, consequently, visual imitation is not
as necessary as auditory for learning the sounds of the mother tongue.
Specifically, one of the blind girls who continued to be studied by Mills until the
At 28 months, he made fewer phonological errors at this age than a sighted child did.
was at a similar level of linguistic development (with an average length of
emissions or comparable LME.
Let's now analyze the data we have on word imitation and
phrases. Most of the authors who have studied this topic agree in pointing out
that in the absence of vision, children often imitate words very frequently and
phrases heard previously and that, often, these repetitions are made in a way
stereotyped and inappropriate. Such repetitions, of an 'echolalic' nature, are
characteristics of autistic children, which has often led authors to
to consider, at times incorrectly, that blind children have problems with
autism associated with blindness. Certainly, some blind children present
disorders similar to those of autistics, but that does not mean that blindness and autism are
they are necessarily associated. As previously mentioned, it is the lack of a good
relationship with the people around them, with the resulting problems in the
formation of intentional communication, which causes blind children to be able to
having stereotyped self-stimulatory behaviors, such as echolalias, to
What helps the lack of stimulation from the outside world that blindness entails.
.
However, not all the imitations of words and phrases that are repeatedly made by the
blind children can be considered echolalic. On the contrary, many of them
they have an evident functional value when vision is lacking, as they constitute forms of
non-visual imitation. If we momentarily abandon our perspective as sighted individuals
and we find ourselves in the phenomenological world of a two-year-old child who cannot
see, we will understand that, in many cases, the repetitions of words and phrases
they are useful for the blind child for communication and language acquisition, thus
as for the making of fictional games.
For our part, we think - and again we must warn the reader that we do not have
research experience in this area-, that the repetition of words whose
The meaning is unknown, it could serve the blind child precisely to "ask for help" from the.
adults around him in the acquisition of those meanings: Despite the fact that the
the use by the blind of words whose meaning they do not know has come
often considered a negative phenomenon called 'verbalism', it is
possible
that in the early stages of language acquisition, the repetition of words can
to serve to 'remedy' the lack of knowledge about the
objects of the outside world that blindness entails. Specifically, our hypothesis
suppose that when the first words that the child utters repeatedly do not
are produced in contexts of interpersonal communication, when the people who
surround the blind child do not understand his communicative attempts, surely those
imitations will eventually have an echolalic character. On the contrary, if in the mother and in
the remaining people surrounding the child are given the interpretative conditions and
appropriate attention, they will be able to provide you with the meanings
corresponding to the word that imitates, both by making him touch and hear the objects
that term refers to, by providing them with labels or explanations
verbal expressions of the same in a language appropriate to the child's level of development. Thus,
In general terms, the repetitions of words by blind children cannot be
considered "a priori" as lacking function. Only when such
verbalizations occur in a repetitive and stereotyped manner, without intentions
communicative and are accompanied by signs of disinterest in interaction and the
communication, we can assume that we are dealing with echolalias, and that therefore the child has
problems in secondary or intentional forms of intersubjectivity.
We believe that the data obtained by Bigelow in his 1990 research can
to align with the hypothesis that has just been proposed. The author did not find that the
overcoming the permanence tasks of objects outside is a necessary requirement for
the emission of the first words by blind children. On the contrary, the
two totally blind individuals studied by her were able to emit 50 words in one
The reader will find the exact meaning that we attribute to the term 'remedy'.
in the last chapter of this book.

evolutionary stage in which they had not yet passed the corresponding tests of the
permanence of objects.
On the other hand, it should be considered that auditory-verbal imitation is perhaps the way
more suitable than the blind child to reproduce -to later deform playfully in the
fiction game - various scenes of family life. Urwin, in an excellent job
on the development of communication and language in blind children published in
1984, she is the first author to highlight the value of verbal repetitions.
as a means for the child to engage in representational play. Thus, in
instead of considering the verbal repetitions of the children studied by her as
"ecolalias" strives to interpret them within the context in which they occur,
considering them as high-functioning imitations. Additionally, as also
Urwin pointed out that children can use these verbal repetitions as a mechanism
to regulate their own actions. By this, we mean that these repetitions
They function as a form of 'self-scaffolding' which means that the child uses them.
as help when carrying out activities that are particularly complicated for them.
We will revisit this data and analyze it more deeply when we
Let us focus on studying the characteristics of symbolic play in blind children. No
However, we find it appropriate to now offer the reader one of the examples of repetition.
verbal that Urwin offers us.
The example is taken from an 18-month-old child named 'Jerry' who rebuilds a
game played with your father 2 hours prior. It is, therefore, a typical form of
imitation in the absence of the model that has a playful nature. The game is called by the
author "Are you sure?" and Jerry's father had used it for several months to
stimulate the child's mobility. Using his own voice for him and a deeper voice
for his father, the child represented the two roles in the following simulated dialogue:
Are you sure?
Are you sure? Jerry's voice: I'm sure, dad. The father's voice: Sure?
Jerry's voice: I'm sure, dad
I am sure, papapa
and bursts into hysterical laughter.
(Urwin, 1984, p.511).
Thus, for Urwin, the imitation of language fulfills a series of important functions in
communication service (to which we will refer in the corresponding section),
but it also serves to imitate the actions of daily life that, later on, are
they will turn into a fictional game. As noted in the example, that kind of imitation
they can also act as external self-regulators of the child's own actions. In
As a consequence, it is very important to take into account the functional value of these imitations.
when interpreting, always within the context in which they occur, repetitions
of words and phrases from blind children. Fraiberg, one of the people who has best
observed and interpreted the alternative routes that a blind child must use in their
development asserts that the imitations of blind children are very scarce and that, in
consequence, their possibilities for playing games of a certain nature are also present.
symbolic. For our part, we believe that, surely, considering the possibilities
that also in this area the language offers to "remedy" some of the
problems arising from blindness could give us a lot of information about the pathways
alternatives to the vision for the construction of symbols. Consequently, we are
about a topic whose research should be addressed in the near future.

2.3. Preverbal communication

The research conducted in recent years from a perspective

interactionists point out that the origins of language are located in the
communicative interactions that occur from the early stages of life between
the baby and its attachment figure. Thus, long before we can talk about communication
verbal, strictly speaking, there are non-verbal communication guidelines
between the child and the adult to which, precisely because of their formal similarities with the
real conversations (rhythm, respect for turns, maintaining eye contact,
etc...) has been referred to as 'protoconversations'. The origins of communication and the
language is in the first communicative interactions that the mother establishes with
your baby from the earliest stages of their life. As mentioned when discussing attachment, the
a child comes into the world with a series of reflexive behaviors that tend to prefer the
stimuli coming from other human beings that will soon become the
referred to by Trevarthen as "primary intersubjectivity". For example, it prefers
acoustic patterns similar to the human voice and synchronizes its body movements
with the speech segments of the adult. It also primarily addresses
visual configurations of the same type as the human face, being able to, very soon,
fix and withdraw your gaze in the eyes of the adult, as well as imitate their movements.
mouth. In the same way, the newborn is capable of emitting social communication signals
how they have the same gaze, the grimaces similar to a smile and crying. As already
we have said, these behaviors are, at first, reflexive in nature, but the adult makes them
attributes intentionality to them and interprets them as if they were truly endowed with
intentions. Precisely thanks to that interpretation made by the mother and to the
adapting their behaviors to those of the infant, it is possible that patterns will develop
preverbal communicative interactions mother-baby
the "proto-conversations" that are undoubtedly guided by this in these early stages.
adult. It is important to emphasize, due to its repercussions on the study of development of the
first communicative guidelines in blind babies, that the behaviors of
"primary intersubjectivity" that the infant has, will only become
intentional if the adult is able to attribute communicative intentions to them, that is, to
interpret them, exaggerate them and respond in the appropriate manner.
Approximately in the second half of the first year, if certain have been established
good relationships between the baby and their attachment figure, they will begin to develop
the intentional communicative guidelines referred to by Trevarthen as 'intersubjectivity'
secondary school." It is at this moment when the baby stops being interested separately in
the objects and by the people to communicate with them about the objects in the
process called "triangulation." Consequently, it is from here that emerge
the proto-imperative and proto-declarative forms that involve asking for objects and
communicate with the adult about those objects. According to Bruner (1983), it is in
this stage of development when the child and the mother engage in numerous games with
objects that constitute the basis for developing the sequence of turns involved in the
conversations. It is about action games such as 'give and take' and 'put in and take out'
take out", etc., in which precisely the exchange of roles between the couple (once
it is the child who gives the object and the mother who receives it, while in others the
sequence is reversed), it is a precursor to the deictic mechanisms involved in the
subsequent verbal conversations, such as the distinctions "I", "you" or "here"
"there." Likewise, joint attention games begin, such as looking at a book and the
mixed games in which attention and action are jointly involved such as the
typical game of 'peek-a-boo'.
As we will study next, when a baby is born without having a system
as important in the human species as the visual can be altered so much the
first forms of unintentional communication, like the later ones, of a character
intentional. Of course, the blind baby has a good number of behaviors of
"primary intersubjectivity" alternatives to the vision, but it is possible that the adult is not.
able to interpret them, to adapt to them, or to guide communication, which, without
doubt will cause problems in the development of secondary intersubjectivity, of the
intentional communication. On the other hand, even if they have been established normally
the emotional relationships and the first communicative forms between the baby and its mother, the
the problem may arise precisely when introducing objects into the preverbal "dialogue".
the process of communication about the external world. As we will see next,
blindness poses difficulties in the development of preverbal patterns of a character
protodeclarative and protoimperative, as it is difficult to interpret the mechanisms
alternatives that blind babies develop to direct adult attention towards
the objects and to share with this his interest in said objects. Furthermore, in relation to
With this, it should be noted that the blind child develops more slowly and at a greater cost.
that the seer a world of permanent objects, which necessarily entails that one
they delay their own initiatives to draw attention to what interests them and to start
the game with objects. It is very necessary that the adult in charge of the child's care
blind
stimulate this one's interest in the outside world to the fullest and promote play
shared with objects that, as we know, are of great importance for development
of the guidelines for role changes that characterize conversations. As
We will study later the problems that blind children have in emission.
the deictic terms are most likely related to the difficulties
previous in this process of "triangulation". Based on the research of authors
like Bates (Bates, 1975; Bates et al., 1979), the studies conducted on the
preverbal communication between sighted babies and their parents emphasizes the importance
of the visual system both for the development of the first communicative forms in children-
adult, as for the subsequent child-object-adult. However, as will be studied in
continuation, there are alternative forms of communication to vision among which are
highlight the bodily contacts and verbal exchanges. Probably, the
the importance of the latter in early childhood goes unnoticed
accompanied by looks and gestures in normal children. However, to study the
the relevance of verbal exchanges for the development of communication,
we would have to look into the early patterns of communication that are
they develop between deaf children and their hearing parents.
We have little information about the communication guidelines established between the
blind baby and their attachment figure during the first six months of life,
probably because -except for a few exceptions- researchers usually have
problems when it comes to early detection of the families to be studied. Nevertheless, the
works already discussed in the section dedicated to attachment, the research carried out on
recently held at Stockholm University by Junefelt, Palmer, and Preisler, and
some of the data from Urwin's publications (1978 and 1984) allow us to make
certain statements regarding this.
We have repeatedly stated that, even in the absence of vision, newborns rely
with a good number of prefigured behaviors that tend to interact with the
other human beings. Consequently, if the mother (or the person primarily responsible
of the child's care), knows how to interpret and guide these behaviors, the baby will develop
normally the first forms of unintentional communication through ways
alternatives to vision. Thus, all the research conducted on this concludes
that, between blind children and their mothers, communicative interactions are established that
they can be considered proto-conversations. Specifically, Preisler (1991), when studying the
interaction that occurred between 10 blind children and their mothers, found that at the stage
between three and six months of age, babies communicated with their
mothers, through smiles, lullabies, and vocalizations, and who took part
active in rhythm games and songs with bodily contact. When they were
carried in their mothers' arms, they reacted with smiles, an increase in
motor activity and even making efforts to 'talk'. They also used these
same means
to provoke the initiative to make contact by their mothers. It is important to note
According to Preisler, all the mothers participating in the study were very
interested and motivated to establish an intersubjective relationship with their babies, which
it allowed them to interpret and stimulate their communicative attempts. Results
similar findings were obtained by Junefelt (1987), in his detailed study of communication patterns
developed between a blind baby and his sighted mother. In her work, the author describes
numerous sequences of corporate and verbal communication that replace those of
visual character. It is important to highlight the alternative pathways to vision that both
members of this diad were able to use to establish shifts of type
protoconsversational: the blind baby made bodily movements and vocalizations that
were interpreted by their mother as conversation turns and, consequently,
answered in some way, to continue these first games of exchanges of
roles.
Urwin (1978 and 1983) also found a quite satisfactory development of the
interaction between blind children and their parents during the first year of their lives,
interaction for which they used alternative pathways to vision. The data that we
this author's findings are consistent with those of Preisler and Junefelt, although she does not cite them.
exactly the age in months when the interactions took place. Urwin observed
that all mothers tried to look for some sign of behavior in their children
attention or response they might consider as "an answer" to their own
initiatives. To do this, they looked at their babies' faces in order to find in them
movements or fluctuations of the mouth that could be taken as a signal of attention to
their verbalizations. Similarly, they encouraged their children to play games with them.
roles both verbal and tactile-kinesthetic, through contacts, tickles and
body movements of all kinds, which can be interpreted as examples of
protoconversations
Consequently, we believe that visual exchanges are not, as many authors
hypothesize. essential for the establishment of the first forms of
communication child-adult. since they can be replaced by vocal interactions and
verbal, as well as through exchanges and tactile and rhythmic games. However, we think
that the results obtained from the research reported here cannot be
generalize to all the dyads blind child-sighted adult. It is important to take into account that the
mothers who participated in this work had considerable information about
the development possibilities and the communicative abilities of their babies. As
We know that, at this stage of 'primary intersubjectivity', the child lacks intentions.
communicative and it is the adult who guides the interaction attributing intentions to the
actions of your baby. Thus, as we have repeatedly mentioned, it is absolutely
it is necessary for the parents of blind babies to receive information programs in the
that, among other things, they learn to understand alternative communicative signals to
the vision that their children are going to use to communicate with them. In case they do not
establish a good relationship between the baby and the adults around them, so that they do not
they know how to interpret their emotional needs, they will not develop adequately
first forms of interpersonal communication and, consequently, can reach
problems may arise in access to 'secondary intersubjectivity' with symptoms of
autistic character.
Having come this far, we move on to analyze the impact of the lack of vision on the
development of intentional communication, at the moment when child and adult integrate
to objects in their 'protoconversations'. According to Urwin (1984), blindness
it raises problems that can seriously affect the process of 'triangulation'. In
First of all, vision plays an important role in the regulation that the baby has of the
Adult attention. It is the looks and gestures of pointing that allow this person to know
what the child wants to do, their intentions towards objects; the forms
protodeclaratives and protoimperatives that babies use to get attention from
their mothers about the objects are, undoubtedly, of a predominantly visual nature
manual. Additionally, as we know, the lack of the visual system causes the blind child to be
considerably delayed compared to the seer in the knowledge of - and by
consequent to the interest in the objects of the external world. While in the
in the second half of the first year of their life, a sighted child can point to a toy and
thus indicate to his mother the interest he has in that object, a blind person will 'not know' either
at least there are objects outside their immediate environment. Thus, probably, only
when the blind child has acquired the notion of permanent object, he will be able to
be interested in distant objects and, consequently, initiate the dialogue about the
the same using protoimperative and protodeclarative forms through pathways
alternatives to vision. However, it is possible that, if the conditions are met
adequate, the blind baby and the adult can establish, more or less at the same
age margin that sighted children, preverbal communication systems about the
objects close to the child with which he has tactile experience, although the initiative
for communication must more frequently start from the adult in these early
stages, that when these interactions occur with sighted babies.
Despite the fact that, according to Urwin, blind children from the three communicative dyads
studied for her were developed extremely well in terms of the
preverbal communication guidelines, and that there are certain similarities with the forms
developed by the seers, the author does not hesitate to assert that blindness entails
important peculiarities in the process of 'triangulation'. In relation to the
similarities between the blind and the sighted, Urwin found that the ability to regulate the
interaction arose in the early ones at the same age that other authors had described
for the seconds. Thus, blind children, during the last quarter of the first year
they were able -just like the seers- to maintain the interaction, either by repeating
procedures that had previously been successful in attracting the attention of the adult, or
well coordinating people with actions and objects.
However, there are undoubtedly disadvantages and problems caused by blindness: in
concrete, the regulation of adult attention when the baby and the adult do not maintain
physical contact. Although in the period corresponding to the end of the first year, children
blind individuals studied by Urwin were capable of inciting and controlling the attention of their
parents once the interaction was initiated, to do this they needed to be in
physical contact with them and, therefore, depended on the prior decision of the adults of
put themselves at your disposal.
The data obtained by Urwin also confirms the existence of important
differences between blind and sighted children in relation to the use of gestures
reach and point to ask and indicate, as well as in the games of offering and exchanging
objects with adults. Although in the three dyads she studied there were produced
coordination child-object-adult within an age range comparable to that of sighted people,
the means used by blind children to attract the attention of adults about
the objects were
very different from the ritualized gestures used by the seers. Specifically, instead of
of gestures, they used vocal exchanges and elaborate forms of body games.
On the other hand, from our perspective, the examples that Urwin provides in his article
of
1984, on the gestures used by blind children to refer to objects.
they seem to have to do with the process of 'triangulation', but rather with games of
turns that involve only the child and the adult. It tells us, for example, that one of the children
he was able to clap to encourage his mother to do it too, and that
another could maintain long imitative sequences in which he hit the objects for
produce sounds and, while he was on his father's knees, he was able to ask him to
he will lift her in his arms using demand vocalizations and 'stretches' or
ritualized bodily pulls. On the other hand, none of the three children was able to,
end of the first year, indicating distant objects, nor spontaneously offering objects to
the adults to start games. In two of the cases, the children were able to offer
objects with some frequency, after a training done deliberately by
the parents, but in the third one, this type of behavior was not observed until the beginning of
third year.
Preisler (1991) in his work with ten mother-child blind dyads, obtains
results similar to those of Urwin, although he seems more pessimistic in pointing out the
problems that a baby's blindness causes in child-object-adult relationships. From
according to this author, during the period between seven and nine
Months, blind children begin to show curiosity and interest in objects. When
the babies are manipulating the objects, their mothers interpret the movements of the
hands of these as if they were gestures or signs of interest in them and make comments
about the child's activity, thus trying to "share a topic" with him. However, it
it addresses the forms of interpretation by the mother since, according to Preisler,
the child still shows no intention of sharing with her his interest in the
objects. At the end of this period, the blind child can interact with their family members,
but the relationships focus solely on the child-adult dyad, without being able to integrate into
she the objects. Upon turning one year old, the blind child still has difficulties in the process.
from "triangulation" as they cannot look at and point to objects and share their gestures
with the looks of adults. However, from this age onward, blind children
they were beginning to be able to use alternative ways of vision to attract attention to the
adults in relation to sound objects, although when they listened, their bodies
and their faces remained motionless. The observations collected on video showed
that these children directed their attention towards the sound through a slight inclination
towards it. The author believes that this movement could serve as a means to
establish communication with the adult about the objects whenever they could
to interpret those movements or 'body signals' as interest in the
objects. However, it seems that it is very difficult for the relatives of the children
blind to interpret and even realize the existence of those possible paths
alternatives to indicate, when the child's face and arms remain still and
unexpressive. This is a problem that, like many others previously mentioned, can,
at least, to alleviate using education and training programs for people
in charge of taking care of blind children.
The comparison between children who were completely blind and those who had
some visual remains show that, even having very little vision,
greatly facilitated the triangulation process. All visually impaired children
included in the work they used looks and gestures as a means of showing
intentionality towards objects. Thus, the author states that two of the girls, with a
residual vision of 0.1 in one of the eyes, established forms of "intentionality"
secondary school" at twelve months. The child who only had a visual remainder of 0.01 managed to
communicate with their mother about objects at around 13 months, while
that totally blind individuals only achieve this at an age of approximately 21 months.
Unfortunately, Junefelt's research (op. cit.) does not provide us much
information about when and how a dyad formed by a blind child and a mother
seers integrate objects as the theme of their protoconversations. As it was of
wait, the author did not find pointing gestures in the blind baby, although there were behaviors of
"to lend a hand" that is not analyzed in their study. Although it offers us a series of
examples of the use of manual and bodily gestures referring to objects
externals, which occurred at the age of 30 months, we cannot consider this age
as representative of the group of blind children. The child studied by Junefelt,
suffered from epilepsy episodes at 18 months and had strong medication, which left him
it produced a significant setback in its development. Moreover, it had problems
neurophysiological articulatory factors that delayed their language acquisition
verbal. Although the author claims that the mentioned child quickly recovered from the setback.
suffered at 18 months and that their communicative development was normal, we cannot
consider it as a blind child whose only deficiency is blindness.
In summary, the limited data we have forces us to be very cautious about
the repercussions of blindness on the development of preverbal communication.
In any case, it seems that the lack of vision, in itself, does not have to affect
the first forms of child-adult communication. When the adult is able to
to understand and, consequently, to interpret the alternative paths available to a baby
Blind to show interest and affection for people, there is no reason for it to be
alter these forms of communication. Precisely, that has been the case for all the
mothers (or fathers) involved in the studies we have reviewed earlier, because
What, without a doubt, they and their children developed very effective forms of communication.
through alternative means to vision that included 'turn-taking' games thus
as mechanisms used by the baby to regulate the adult's attention. Without
embargo, it seems that blindness does pose problems when integrating the
objects in the communication between the child and the adult. First of all, as already mentioned,
The lack of vision leads to problems and delays in the construction of permanence.
the objects, about
everything when it comes to sound objects. Consequently, a blind child will not be able to
share with the adult their interest in distant objects until they are capable of
identify them by sound. However, we think it will be easier for you
establish the process of 'triangulation' in relation to nearby objects with the
that has tactile experience although the data we have on permanence
from tactile objects, they also lead us to predict a certain delay in communication
regarding these objects. This problem is compounded by the difficult substitution through
non-visual sensory systems of pointing gestures and directing gaze to indicate
an object on which the interlocutor's gaze is fixed. Preisler's research is the
the only one that offers us certain optimistic perspectives regarding the possibility of finding some
alternative form to the vision of the 'proto-declarative' and 'proto-imperative' gestures that
they regulate the adult's attention towards objects. In any case, we consider it very
it is necessary to design new investigations in which the
process of 'triangulation' in blind children and in which it is investigated whether there are pathways
alternatives for the blind child to show the adult their interest in sharing with them
objects.
This would allow us to inform and make parents aware of the possible ways.
that their children could have to show interest in objects, as well as in the
possibilities they themselves have to foster child-object communication
adult. In any case, we believe that in this situation we find ourselves
of difficult solution in the absence of vision, as we will see later the greatest
part -if not all- of the studies on language acquisition find that children
blind people, even when they are well stimulated and have optimal development, have
problems in the understanding and issuance of the deictic terms involved in the
speech. For our part, we believe that the origin of such problems lies,
specifically, in the difficulty of using alternative preverbal deictic forms to the
vision.

2.4. Acquisition of oral language

Since the beginning of the 1970s, a good number of works have been published.
about different aspects related to the characteristics of the first language of
the blind children, some of whom offer us contradictory results. Those
discrepancies can be explained both by the heterogeneity of the topics studied,
how
due to the disparities between the subjects and the methods employed. But, without a doubt, also.
they are due to the fact that the results obtained in the investigations have been interpreted as
one way or another, depending on the theoretical framework adopted by its authors. Thus, from
the generativist stances inspired by Chomskyan theory - of which they constitute
clear examples the publications of Landau and Gleitman (1985) - they do not have to
there are differences between the language acquisition of blind and sighted individuals
the acquisition occurs independently of learning or experience
extralinguistic. On the contrary, from empiricist approaches, the lack of
An experience as important as that provided by the visual channel must originate
serious problems and delays in the linguistic development of blind children. Precisely
these problems, as well as the existing differences between the language of the blind and
seers, have been cited by authors such as Cutsford (1951), Burlingham
(1961), and more recently by some others such as, for example, Andersen, Dunlea and
Kekelis (1984), Mills (1983), Mulford (1988), or Dunlea (1989).
For our part, without wanting to enter at all into the controversy between generativists and
empiricists, we will present in the most objective way possible, the different
data and interpretations that we have found in the studies on the language of
blind children. Undoubtedly, our own interpretation of the data cannot either
to be considered atheoretical since, as has already been said, we take as a framework of
reference the theories
about the social origin of language related to Vygotsky and Bruner. Also our
experience in research on various aspects of development and learning
of blind children, advises us not to disdain the peculiarities that may arise
in their language acquisition process. It is not about adopting a stance
"differentialist" that leads us to confirm, without further ado, the possible differences that exist.
among the guidelines for the language development of the blind and sighted, but not to overlook
or deny the existence of such differences. We propose, on the contrary, to analyze and
to study the peculiarities of the linguistic development of the visually impaired (just as it has been
made in the corresponding section on preverbal communication), in order to verify
its functionality, as well as its coherence with the phenomenological experience that the
blindness entails.
Fortunately, we already have a certain number of research studies whose authors
they address different aspects related to language development and
communication in the visually impaired from this perspective. Such works, among which
it is worth highlighting those of Janson (1988), Pérez Pereira (1991 and in press), Pérez Pereira and
Castro (1990 and 1992), or Urwin (1979, 1983, and 1984), have allowed us to maintain and
to develop our own theoretical stance on a topic as complex as acquisition
of the language.
According to Pérez Pereira and Castro (1992), the aspects of linguistic development of
the blind that raise the greatest controversies among different authors are: the
development of the lexicon, the language that adults direct at the blind child, the use of
personal pronouns, the use of language to provide information about external events
and personal wishes and the linguistic styles of blind children in relation to those of the
clairvoyants. We will analyze these aspects on the following pages, but not before making a
brief reference to phonological development. As the reader could verify in the section
3.2. of this chapter, in which we analyze the importance of visual imitation and the
auditory in the acquisition of the sounds of one's own language, researchers seem to
agree that the phonological development of blind children can
to consider oneself 'normal', even though certain peculiarities are present.

The acquisition of vocabulary

Mulford published an important review and analysis work in 1988.
recent investigations conducted by the most relevant authors in the
study of vocabulary acquisition by blind children. The author collects
the data of 15 blind children without associated deficiencies, who had had good
relationships of interaction and communication with their families and, consequently, a
fairly acceptable psychological development. This involves children studied by different
authors from whom Mulford has occasionally taken published research
(Bigelow, 1981 and 1987; Landau, 1983; Mills, 1983; Urwin, 1978 and Wilson, 1965) and, in
others, the data that were specifically provided to him by the researchers themselves
(Andersen and Junefelt).
In contrast to the research by Norris, Spaulding, and Brodie (1957) and
Fraiberg (1977), who found a certain delay in the age of the first issuance.
words from blind children, Mulford does not find it when comparing the
data of their subjects with the normative data of sighted children (Nelson, 1973). Thus,
the age of onset for the first word was 14.7 months for the blind, which
it can be considered within the normal range, although it should be noted that there are
notable individual differences among these children as their ages ranged between
9 and 24 months. Regarding the ages of issuance of the first 10 and the first 50.
words, the author also found no signs of delay in blind children. In
concrete the Middle Ages for the first 10 words of the seven blind children of the
that available data was 15.1, exactly the same as that of the clairvoyants.
The average age at which children (in this case 15) produced a total of 50 words was
20.1 months, while the average obtained by Nelson for sighted individuals was
of 19.6 months.
Thus, Mulford concludes that, from a quantitative point of view, there is no delay in the
acquisition of vocabulary in the blind children studied by her. The existing differences
regarding the data from Norris et al. and Fraiberg, they are explained by this author
through two factors. Firstly, Norris et al. included subjects with
certain deficiencies that attribute to the association of neurological problems to the
blindness caused by retrolental fibroplasia. Secondly, the data on
lexical development was obtained by both authors through development scales the
which undoubtedly provide much less accurate information than newspapers
lexicons and the records used in the research reviewed by Mulford.
To carry out the qualitative analysis of the initial lexicon of blind children, we will base ourselves on
also, preferably, in Mulford's work (op. cit.). However, it should be noted
that our own interpretations of the data sometimes differ from those mentioned
author in the sense of seeking greater functionality and coherence to the
peculiarities of language in the absence of vision. Likewise, we will use the valuable
information provided to us by Pérez Pereira and Castro in the aforementioned works
previously, on the type of lexicon used by a blind girl and her sighted twin
between 29 and 41 months of age.
It is specifically about knowing what type of emissions children use in their
first language and if this language differs from that of the seers both in its composition
As in its application. For this, Mulford analyzes, using Nelson's categories, the
data obtained from the research of Andersen et al, Bigelow, Landau and Wilson.
Subsequently, compare the results of blind children with those obtained by the
own Nelson for the sighted in 1973. The most notable differences between the two
groups of children are as follows: the blind use a greater proportion of names
specific and action words, fewer general nouns and
they practically do not emit functional words.
But before analyzing those differences in depth, we believe it is necessary to make
mention of the controversy that exists among different authors about whether blind children
they use their own forms or 'idiosyncratic' words in their first broadcasts and yes,
as happens also in the case of the seers, there is a certain 'mortality' or forgetting of
some of the first words that these children utter. Andersen et al. in their work
from 1984, they precisely point out the absence of these two phenomena in the first language
of blind children, which leads them to conclude that the vocabulary of these children is
less innovative and more dependent on that of adults. In contrast, Urwin (1978) and
Wilson (cf. Mulford, 1988) recorded in their records a certain number of
"protophrases" or idiosyncratic forms emitted by blind children. Likewise
Urwin, in the same publication, also noted that his children, after having
having used a word repeatedly for some time, they seemed to forget it for a while
several weeks, a period after which they included it back in their repertoire. From
from this data, we can conclude nothing about the differences between blind and sighted people in
Regarding the innovative character of the first lexicon. Consequently, following Mulford,
we thought it would be necessary to conduct new research to clarify, for a
side, the possible individual differences that exist among sighted children in the
use of idiosyncratic forms and in the mortality of its lexicon and, on the other hand,
existence or absence of such characteristics in the lexicon of blind children.
Regarding the names, all the authors who have studied this topic
they agree in concluding that, in the absence of vision, children often use, in these
initial stages of language acquisition, common nouns as if they were
own or specific. For example, Bigelow (1982) informs us that one of his
subjects used the term "bunny" only to refer to a rabbit of
toy, as if it were its own name. This phenomenon - which undoubtedly also
produce, although to a lesser extent, in the first language of sighted children- it
derives, logically, from the problems that exist in these early stages for
generalize and form categories, when the experience one has with the objects of
The real world is, still, very scarce. In the case of blind children, it is absolutely
It is logical to find problems in this area. Without a doubt, the lack of the visual channel makes the
the possibility of forming categories through generalization is diminished. Imagine the
reader the difficulty
what a blind child must have to build, with the data provided to him
touch and hearing, different categories, such as those corresponding to vehicles
or animals.
However, when Mulford compares the type of common or general names that
blind children emit with Nelson categories for sighted, only find
differences between both in the semantic categories that refer to furniture and objects
domestics on one hand, and animals on the other. In the remaining analyzed categories
food, clothing, toys, vehicles, personal items, kitchen utensils
objects outside the house, places, body parts, people and 'others' - do not appear
important differences between the two groups of children.
We believe it is unnecessary to dedicate a lot of space to explain the reason why of the total
Of the words spoken by blind children, 22% correspond to names of objects.
domestics (compared to 9% in the fortunetellers), while only 8% refers to
names of animals (20% in the seers). Undoubtedly, the fact of having to collect
the information about objects through touch, means that the child, in these
first stages, preferably name objects with which he/she has been able to have
direct experience, such as the furniture and utensils in the house. Just the
the opposite happens with animal names, which are difficult to perceive when they are missing.
the visual channel. Mulford's data (op. cit.) indicates that blind children
practically only emitted words for domestic animals (dog, cat, and bird), which
they are precisely those that blind children can know through perceptions
tactile and auditory. The remaining animals -and their names- are usually known by the
children from photographs and drawings that, logically, are not useful for children
blind. The substitution of these
images for others of a non-visual nature, although it is useful, poses greater problems to the
time for the child to be able to form the corresponding prototypes for the categories of
Animals. Without a doubt, toy animals bear little resemblance to real ones.
when explored with hands.
Precisely this data about the first words spoken by blind children
they seem to go against the hypothesis of 'verbalism' (Cutsford, 1951). As has already been
said, some authors have considered that the language of blind people is
verbalists in the sense that they often use words without knowing their meaning.
The fact that the first words of blind children refer to,
preferably, to those objects that are situated in their close environment and that, in
consequence, they know, seem to indicate that we cannot uphold such a hypothesis in these
initial stages of language acquisition.
In this regard, some authors point out that in blind children, it does not occur the
phenomenon of 'overextension' so common in the initial language of the seers. It
it talks about overextension when, for example, a child who knows the word 'dog'
use this same tag when you find another animal that you haven't seen before, like
for example a cow, in a process that will lead her to the construction of the category
"animals". Certainly we have not found any example in the literature of
overextension in the language of blind children, but we are sure that one
rigorous and not 'visual-centric' research on the subject would lead us to find this
type of phenomenon in the language of the visually impaired. Undoubtedly, the overextensions are
would be based on
similarities of a tactile, auditory or gustatory type that may possibly prove difficult to
detect for a sighted person.
Let's now analyze the category related to action words. According to
the data provided to us by Bigelow (1987) and Mulford (op. cit.), blind children
emit a greater number of terms related to actions than the seers, although, upon
just as happened in the case of specific names, they are used in contexts
restricted. By this we mean that these children use such words to
to refer to one's own actions and not those of others, as well as to make demands and
requests. This is also characteristic in the first action words they use
the sighted children, although they will soon start referring to the actions of others. By the
on the contrary, none of the reviewed authors have been able to find words referring to the
actions of others during the period when blind children emit a single word.
Even in the stage corresponding to two-word phrases Urwin (1978) and Dunlea
(1984), they very rarely detected emissions related to foreign actions.
Also Pérez Pereira and Castro (1992 and in press), in an excellent work done
about the pragmatic functions of the language of a blind girl and her sighted twin,
they found that the blind girl emitted more words related to her own
actions and desires that the seer, in the periods corresponding to the broadcasts with
mean longitudes (M.L.E.) between 2.13 and 3.26. However, these authors do not reach
radical conclusions like Dunlea (1984), according to which blind children
they would not use words to refer to the location or the properties of objects,
nor for the actions of others. Sandra -the blind girl studied by
Pérez Pereira and Castro- issued few, but some terms to refer to
locations and properties of objects. In addition, the scores obtained by this
girl in the category corresponding to "description of events" that refers to the
actions taken by other people and external events, were not different at all from
those of her sister.
Again, the explanation of everything that has just been said is in the limited access to the
external information that children without vision have. Thus, we consider it natural that the
the first words of these children do not refer to events that -like the
actions of people and external objects - cannot perceive and, therefore
unaware. However, the fact that blind children use many words
to refer to their own actions and desires, along with some other characteristics of
his language that we will refer to later, has led to authors like Dunlea
and Bigelow considers that the language of these children is 'egocentric'. We will discuss
with greater depth the possible egocentric characteristics of the language of the
blind people while studying, in the following section, the functions it fulfills. By the
moment
we prefer to think that the first words of children preferably refer to
the objects and actions they know and that, consequently, the blind will take longer
time that the seers take to know and, consequently, to describe the actions of the
people and external objects.
If we now consider the category corresponding to modifiers, the data from
Mulford (op. cit.) points out that such terms appear very rarely in the first
language of both blind children and sighted ones. However, those who are most
the blind used to refer to temperature states, ("hot" and "cold").
They also mentioned, although briefly, other states, locatives, and attributes, no
finding examples of possessives.
Some of the blind children expressed relational terms (more), although it does not seem
to be clear the context in which they occurred. Thus, the children studied by Dunlea (cf.
Mulford, o.c.), they said "more" and "no" to express rejections and requests, but not to
referring to the appearances and disappearances of people and objects: Of the three children
studied by Urwin (1983), only the one that had visual remains was used, at 18
months, the words "there" and "more" as declarative and imperative forms with which
they referred to the appearance or reappearance of objects. Similarly, only that child
said "no" or "it went away" to refer to the non-existence of an object whose presence
I was expecting. This author finds it difficult to explain the absence of these terms.
in the language of blind children since, as it tells us, the three children by her
studied had already acquired the permanence of the objects. From our point of
the delay in the acquisition of this type of words is directly related
with the problems in the use of protodeclarative and protoimperative forms
alternatives to the visuals. As was said when talking about preverbal communication, the lack
vision poses serious difficulties in the early stages of communication
intentional that undoubtedly involve delays and difficulties in the initial forms
communicative aspects of language. We will revisit this important topic in the section
corresponding to the pragmatic functions of the language of blind children.
If we analyze the category corresponding to personal and social words, in terms
In general, it can be said that blind children used something more than sighted ones.
type of words. The lexical repertoire of all the studied children (except for the two
subjects of Bigelow, 1987) contained words to express emotional states and relationships
social. Many of the words included in this category are social routines, but
it also includes terms that express the affective states of the child himself, more
specifically that of joy. Again, we must highlight the need for new
research that studies in greater depth how it evolves in children
the use of verbs referring to one's own mental and psychological states
and foreign. In any case, the scarce data we have does not seem to show that
the absence of vision posed problems when using words that express
emotional states.
Just as happens with sighted children, blind people also use very few
function words in the early stages of language acquisition. Mulford (op. cit.) only
found this type of terms in two of the blind children. Both used expressions
such as "What is this?" or "What is that?" when reaching for an object or like
response to a sound or intense light (of course in a girl with perception of the
light).
Finally, let's analyze whether blind children use words related to
visual perceptions. In the analysis of the first lexicon, only two of the children used
these types of words. For this author, this is probably due to the fact that such terms
they are voluntarily excluded in the language of their parents. Older children (with
L.M.E. of 3.25), studied by Landau and Gleitman (1985), used words such
such as "see", "look", and "show", as well as names of colors.

Some aspects of syntactic development

There are few studies that have been dedicated to the study of syntactic development.
in blind children. We can only offer the reader the data obtained by Landau.
and Gleitman (1985) on various aspects related to syntactic development, so
like those of Pérez Pereira (in press) and Pérez Pereira and Castro (1990) on length
average emissions (LME) of a blind girl.
Consequently, for the study of the development of the LME in blind children
we have the data of the authors that have just been cited. Following the
procedure developed by Brown in 1973, Landau and Gleitman (loc. cit.) analyzed the
average length of utterances in morphemes, in two premature blind children.
These children, who made their first two-word utterances between 28 and 30.
months, they were behind the average of the seers (they were also behind in the
the emission of the first word), although Landau and Gleitman believe that they can
considered within the normal range. However, they later developed in a way that
very quick since, between 26 and 35 months the average length of their emissions
(L.M.E.) increased to 3 or 3.5 morphemes, and by four years old their sentences could be of
four morphemes.
For their part, Pérez Pereira and Castro (1990 and 1992) conducted monthly records of the
The story of two twin girls, one blind and the other sighted, during the period between
the 29 and 41 months. They showed that, from a morphological point of view, the blind girl did not
could not be considered, in any way, delayed compared to the seer. On the contrary,
As can be seen in table 4.4, the average length of their emissions was slightly
greater than that of the seer girl and, consequently, it was normally included in a
highest stage within those described by Brown. The authors interpret these
differences due to the fact that the blind girl used more routines and repetitions than the
seer, what, as we will analyze in the next section, seems to be part of the
types of strategies that blind children use to learn language.
Consequently, we believe we can conclude that blindness itself does not produce
delays in the development of children's emissions. The initial delay of the subjects
studied by Landau and Gleitman is attributed to the problems of prematurity
extremes with which these children were born and to the diseases they had in the
first months of his life.

TABLE 4.4.-Average length of the emissions of the blind and sighted twins
LME Brown Stage Chronological age

Source: Pérez Pereira and Castro (1992), 'Pragmatic functions of blind and sighted'
children's language: A twin case study. First language 12 (34) p.26

Let's now consider the thematic relationships expressed by blind children.

in the first broadcasts of several words. It is the classic way to study the
meaning of children's compositions, the emergence of structure
predicate argument in their broadcasts. Bloom, Lightbown, and Hood (1975) believe that
the development of those thematic relationships reflects both the semantic complexity and the
syntactic, of a determined relationship.
Landau and Gleitman used the categories of Bloom et al. (1975) to analyze the
semantic relationships expressed in the language of their blind subjects. Thus, they compared
the semantic relationships contained in the utterances of these children, in the periods
corresponding to different LME, with those obtained by Bloom in visions. In
concretely, they analyzed those relationships for the first time when the LME of two of the
the children were 1.77 and 1.78, then 2.71 and 3.25, and finally 3.60 - in the third of
The studied girls - The authors found quite a few similarities in the relationships
semantics expressed by both blind and sighted individuals in the different studied sign languages.
the first measures the two studied children predominantly talked about actions
(locative and non-locative) and one of the blind girls referred to actions, just like the
sighted children. The authors state that, in general, the differences found between
the blind and the sighted were neither stable nor relevant and that the existing ones could be due to
more to sample errors as well as to unrelated individual differences
with blindness. For example, one of the studied blind children, the first time that
was studied (with an LME of 1.77) expressed a more limited range of relationships
semantics that the other blind girl and the sighted ones. However, in the evaluation
The following one carried out three months later was able to express all the relationships.
semantics (except for questions with "why"?) and in the same proportions as
the remaining blind and sighted children. Another example highlights that a
of the blind girls studied began to increase their comments about the existence of
the objects just when they diminished in the sighted children. However, the
the authors do not consider this result relevant, as it did not occur in the other blind child
studied. However, from our own point of view, it cannot be ruled out that
hypothesis that lack of vision delays the onset of in children
comments about the objects.
Landau and Gleitman also study in the same work the structure without internal syntax.
of the emissions of blind children, specifically the number and complexity of
noun phrases such as 'the ball' and verbal phrases such as 'throws the'
ball". They used Newport's categories (1977) and their analysis compares the data.
obtained in seers by this author with the blind of Landau and Gleitman, in the
same levels of LME. In general, the results showed that the
the complexity of the language of the blind was the same as that of the sighted of their same level
linguistic. However, the authors find an important exception: all of their
subjects (of the English language) were delayed in the development of the structures
auxiliary verbs.
Undoubtedly, this data is not transferable to Spanish-speaking blind individuals as,
As the reader knows, the structure of English verbs is very different from that of the
castellanos. In any case, it is important to point out that the authors wonder if the
problems in the acquisition of the auxiliary forms of the verbs may or may not
generalize to all words of "closed class," among which these are included.
auxiliary forms. The words of 'open class' are most of the categories
lexical (nouns, verbs, and adjectives) and they are called that because they are open to
changes that occur in the language throughout history. On the contrary the
words of "closed class", quite resistant to language change, are words
"small" and affixes such as determiners (the, this, one), personal pronouns (he,
they), relative (that, which), connectors (and, or), auxiliaries (have), prepositions (in,
derivative suffixes (-ly), inflectional suffixes of verb tenses, gender and
number, etc..
In English, most 'closed class' words are contracted when speaking and are
they say with little emphasis placing the stress of the phrase on nouns, adjectives, and
verbal infinitives. The auxiliary forms of the verbs, since they belong to the words of
closed class, they receive little emphasis and for this reason they are also difficult to learn for the
sighted children, although the delay in their acquisition by the blind is,
In any case, very striking. Landau and Gleitman attribute the delay of the blind.
English speakers in the acquisition of auxiliary verbs to the characteristics of language
what they receive from adults. Previous studies conducted by these authors with children
seers had revealed that the acquisition of these auxiliaries
they were highly and positively correlated with the frequency of affirmative questions and
negatives that their mothers made them, since such questions contain auxiliary verbs.
On the contrary, the correlation with the frequency of imperatives was negative, since
they do not contain those auxiliary forms. As we will point out again at the end of this
section, the existing data on the language that adults direct to the blind child
(Landau and Gleitman, op. cit.; Kekelis and Andersen, 1985) seem to indicate that this contains
many more imperative forms and fewer affirmative and negative questions than the
used with sighted children.
To conclude, it should be noted that in general terms, syntactic development does not seem to be
affected by the lack of vision. In any case, we think it would be necessary to bring to
I have done some work with Spanish-speaking subjects to study whether blindness and the...
characteristics of the parents' speech that it provokes have some effect on the
acquisition of the syntax of our language.

Pragmatic functions

When we try to analyze the functions that the language of blind children fulfills in
its initial period -one-word phrases-, we basically rely on the research
from Dunlea (1982) and Urwin (1984). The first of these authors studied the proportion
General emissions - with communicative intent that they issued in this first period
three blind children and two sighted ones. He found no differences between the two groups of children.
since, in both cases, only a quarter of the emissions were
classified as attempts to communicate a message.
However, both Dunlea and Urwin observe that blind children, as they
those who are acquiring a higher level of language knowledge use it more
frequently that psychics in a non-interactive way. Thus, they are common the
repetitions -apparently non-functional- that these children make of words and phrases
heard beforehand. As stated in section 2.2 concerning imitation,
It is very possible that such repetitions serve an important function in development.
symbolic of blind children. In the absence of vision, children have to rely on
greater degree than the seers, to deferred imitations of a verbal nature that often
they seem to turn into symbolic role-playing games.
When Dunlea (op. cit.) categorizes the first emissions of his more qualitatively
blind and sighted subjects from a pragmatic point of view, find quite a few
similarities between both. Thus, the most frequent category for both groups was the
corresponding to 'requests', followed by that of 'identifications/descriptions'. No
however, it notes differences between blind and sighted individuals in the functions of 'calling the
attention", "offer/show" and "direct attention". While the first only
it was used by blind children, the other two only appear in the broadcasts of the
seers. Again we encounter the problems that the absence of vision
originates in the use of language with imperative and declarative functions. From
according to Mulford (n.d.), children are capable of demanding attention for themselves
the same, but not to direct the adult's attention to the objects that interest them
through the conventional gestures of pointing and showing. For our part, we think
that perhaps the blind child first has to get the adult's attention in order to,
once contact with this has been established, to be able to share the objects that are found
close to the child himself. It is possible that he may also try to make it the adult, once that
has caught your attention, the fact that I offer you some objects of whose existence you are not aware
The blind child. Undoubtedly, new research is needed on this.
important topic. In any
In such cases, such investigations should not seek the same gestures that we use.
seers to point out and show, but the alternative paths that the child can use
blind to share with the adult his interest in objects. Likewise, it should be taken into account
considering the difficulty posed by locating distant objects in the absence of
the vision and the possibility for the child to establish contact with the adult to then
to be able to share the objects with this one.
Perhaps we can interpret in this sense another of the data provided by Dunlea
(a.c.). When this author analyzed the types of 'requests' made by children
blind individuals found that the predominant category was 'asking for objects', followed by
"ask for actions" and "ask for routines". It seems, therefore, that blind children can
use words -not visual gestures- to ask adults for objects and then
share them with them. Mulford (n.d.) points in that direction to the remedial role that
language can be present in the blind from the earliest stages of life: "The
Dunlea's data indicates that once blind children add new functions
communicative to their repertoire, make good use of new tools to make the
things that cannot be done without words" (Mulford, 1988, p. 326). It seems very to us
It is appropriate to interpret the characteristics of the language of blind children this way, analyzing
the peculiar functions that it can fulfill in the communicative development of these
children. This avoids the "visuocentrist" analyses that can interpret such functions
as echolalias and manifestations of an autistic nature.
For the analysis of the later stages (phrases of 2 and 3 words), we have the
works carried out by Pérez Pereira and Castro (1990 and 1992), as well as some
data provided by Janson (1988). The first authors, in the research that
we have already cited several times in this section, they carried out the analysis of the
pragmatic functions that language fulfills in a blind girl and her sighted twin.
They use Dore's categories, to which they add some others taken from Dunlea.
(1982), to analyze a total of 2,814 emissions from the blind girl and 1,530 from the seeing one
in the stages corresponding to the LME that were presented in table 4.4. The
results show that the first girl made a considerably high use of the
following functions: "personal" (especially "action" and "determination")
"internal reports" (a subcategory of "declaratives"), "calls/vocatives" (a
subcategory of 'organization resources'), 'repetition/imitation' and 'routines'. For the
On the contrary, the clairvoyant girl frequently used the functional categories of:
«ofrecer», «mostrar atención», «descripciones» (especialmente «identificaciones»,
"properties" and "locations", as well as "questions/answers".
These data demonstrate that, like the other blind children studied in
previous stages, this tends to use language more to refer to its own
actions and intentions that relate to external objects and events. Furthermore, it uses a lot
also its emissions to refer to itself, specifically, to express actions
what they are going to do in the future, or their own wishes. However, Pérez Pereira and Castro
they are less radical than other authors in considering the language of the blind as
self-centered. Thus they think that in the case of these children, language can
to play an even more important role than in the seers in order to regulate and
to plan one's own actions in the absence of vision. Furthermore, although the blind girl by
they studied it referred to few times in their broadcasts about properties and locations
of the objects, sometimes she did and also this girl referred to,
frequency, to external events. In any case, the research of these authors puts
It is evident that the blind girl, in stages corresponding to LME of 2 and 3 morphemes,
still having trouble using their language with declarative functions and
imperatives, as it offered, showed, and caught the adult's attention on the objects
to a much lesser extent than her clairvoyant sister. However, it should be noted that -
although in small numbers, such functions appear in the language of the blind girl
between 2.5 and 3.5 years, which seems to demonstrate that, in the absence of vision, it is
difficult, but not impossible, to communicate with others about objects.
Regarding the imitations, repetitions, and routines that undoubtedly were much
more used by the blind girl than the sighted one, the two authors of the study explain to us
magnificently the functions that such emissions serve in the development of a
child without vision. Thus, they criticize interpretations in which the use of
imitations and routines would be manifestations of a non-communicative language,
egocentric and -consequently- with traits very similar to those of autistic children.
They are, however, in agreement with authors like Dunlea (1982) on the fact that
many of these emissions can be considered as role-playing, although they consider
which also perform important functions in the very process of acquisition of the
language by the blind.
Pérez Pereira and Castro specifically dedicate one of their publications to analyze in
depth the functions that imitations, repetitions, and routines have in the
language acquisition process of blind children. They reveal that not
can be considered forms of egocentric language since the girl studied by them
I used them to perform speech acts and during conversational interaction, in
concrete, to grab the attention of the partner, as well as to ask, offer, and express
her intentions more clearly. Also, this girl used a large number of
modified and/or expanded imitations, which rules out their mechanical character or.
echolalic.
They attribute a very important role to imitation in the process of
acquisition of the language of the blind, considering that they seem to use the
"gestalt style" in their learning process. With this, the authors mean that
children first learn a certain type of sentence by imitation and then,
they introduce modifications into it, in such a way that the phrase serves as a framework for them to
practicing certain grammatical structures and pragmatic forms through variation of
one only of the elements. Consequently, it seems to be proven that the use
of imitations, repetitions, and routines, as both Pérez Pereira and Castro point out
like Janson, they play important roles in the language acquisition process
of blind children. Specifically, it would be a gestalt learning style that, of
according to the first two authors, it serves a function of 'self-scaffolding' in the
language learning.
To conclude this section, we must refer to one of the most debated aspects in
relationship with the language of the visually impaired. It involves the use of terms
deictics, mainly personal and possessive pronouns, in contexts of
role exchange in conversations. All authors who have studied the
the acquisition of this type of words coincides in finding considerable delays and
problems in their emission by blind children, although the interpretation of such
problems not always being consistent.
Ya Fraiberg (1977) observed that all the children she studied had problems in
the correct use of the pronouns 'I' and 'you', 'me', 'you', both in situations
in conversation like symbolic play. Specifically, these children expressed
considerable difficulties in differentiating between the "I" and the "you" and they tended to refer to themselves
the same in the third person, often using the proper name. Thus, the three
children studied by this author started to use the word "I" correctly at
edades de dos años y once meses, tres años y cinco meses y cuatro años y diez meses
respectively. Precisely the fact of finding these delays even in children
blind people with a good overall development of language led Fraiberg to think that they
It was about a problem of 'self-representation' that led to the absence of vision.
Attribute such a problem to the difficulty that it necessarily represents for blind children.
to build a representation of themselves in the absence of the mirror image from which,
obviously, blind people are lacking.
Urwin (1984) also found that these problems in distinguishing between the 'I' and the 'you'
which, on the other hand, are also characteristic of the initial language of children
sightedness- extended longer than expected in blind children. Thus, Suzanne (the
girl whose development the author followed for a longer time), began to use the
the pronoun "I" to refer to herself as an agent at 21 months, quite early
what others
blind children. Although this did not imply the distinction between 'I' and 'you', since this
the last pronoun was only emitted in set phrases or routines. At 27 months, the girl was
capable of referring to distal objects as well as requests, he continued using 'I' and
I was starting to use 'you' appropriately. Anyway, I still did few
constructions in which others are explicitly referred to as agents of the action and
,
when he did it, he used the third person. Precisely, he started to use 'you', in
situations -both from daily life and symbolic play-, in which I acted
together with his mother and with an object. Since Urwin stopped studying the
Suzanne's language at this moment, we can only know about the further development.
of the second person pronouns.
Andersen, Dunlea, and Kekelis (1983) refer to the existence of a development
similar in their own blind subjects. In fact, even these children began to
correctly use the pronouns that indicate changes of verbal roles in
situations of
verbal game in which children repeat in a delayed and sometimes modified way different
sequences that involve changes in conversational roles. Similarly, these
sequences involved the presence of an object and an adult. However, in contexts
In real conversations, they confused 'I' and 'you' and often referred to themselves in the third person.
person.
These characteristics of the language of blind children reflect, both for Urwin as
for Andersen et al., the difficulties that arise, in the absence of vision, the understanding
from the changes in roles that occur in the conversation. Undoubtedly, they arise from the
problems that these children have in the process of 'triangulation', in the difficult paths
alternatives that must be followed to replace the gestures that attract the adult's attention
about objects. According to Urwin, Bruner's work on the
adult-child game with objects can help us explain the difficulties they have
blind children to acquire pronominal reference. The games of 'give and take'
objects provide the child with the reversibility of roles that will later be reflected
in the language through the use of 'I' and 'you'. Suzanne, like the other children
studied blind individuals had serious difficulties in playing such games. This girl
did not offer objects to adults at the stages when sighted children do so,
Although talking about an object allowed Süzanne and her mother to establish their...
mutual accessibility, they developed very few joint play activities with
objects. The same author (ibid.) informs us that when the blind girl started to
offering objects, she and her mother started to play more games with them. And
precisely in those play activities, that is where Suzanne began to say 'you' from
appropriate form.
As has been said, we are faced with one of the most complex problems that poses the
development of blind children. We certainly cannot reach conclusions
definitive due to the scarcity of the experimental data we have. In any case
In any case, it seems undeniable that the lack of vision creates difficulties in discovery.
of the objects, which lead to new problems when establishing the
intentional communication with the adult. All of this is reflected in the delays they have.
blind children in the use of language to refer to objects as well as in the
understanding of changes in conversational roles. In any case, we cannot
stop repeating the need to carry out new research on this topic. It is
it is absolutely necessary to train the adults who care for children
blind to the impossibility that these children have of using gestures
conventional ways of looking at and pointing to objects. It is possible that certain alternative gestures that
blind children develop in ways that are not understood by the people around them and, in
consequence, the essential interaction mechanism does not occur for the
communication. It would also be necessary to explain the importance of stimulating the
maximum play with objects both in the preverbal period and in the verbal period.
Despite what has been said so far, we cannot be pessimistic about development.
communicative of the blind. Everything seems to indicate that, in a marvel of plasticity,
they manage to overcome the problems posed by the lack of vision through alternative means,
as long as there is adequate interaction with their family members. Thus, we think
that from these early stages of life, language begins to 'remedy' the
problems derived from a lack of vision. We cannot forget that the first
Pronouns that imply changes in conversational roles are emitted by children.
in repetitions or deferred imitations of a playful nature, whose functional value for the
language learning has been highlighted by Pérez Pereira and Castro. We will return to
revisit this topic in the section corresponding to symbolic play.
The language that adults direct to the blind child

Up to this point, the important role of adults has been repeatedly highlighted in the
communicative and linguistic development of blind children. Despite this, there are very
few studies that examine these aspects together in a child-parent dyad
adult. In relation to the communicative styles of parents, we have the work
from Kekelis and Andersen (1984), as well as with some data they provide us
Landau and Gleitman (1985). According to these authors, there are similarities, but
also differences, in the language that adults direct to blind children and these
They become older as the child grows.
The two investigations show that mothers used many
imperative emissions and few declarative ones in the observed period. In
concretely, Andersen and Kekelis (op. cit.), point out that between 19 and 22 months, the use
the declaratives increased considerably in the mother of the seeing child and not in the
of the blind. The latter continued to predominantly use the forms
imperatives to direct the child's attention and gave the child less information about
the objects in their environment. In addition, the declarative forms that were directed at the children
were qualitatively different in the case of the blind and the sighted. The mothers of the
first they gave much less information than. including details about the properties
of objects, people, and events, limiting itself to using mere labels (such as for
example "this is a dog"). The authors attribute this to the difficulty that they have
mothers to know what type of information blind children may be attending to
what characteristics of the objects may be relevant to them. Regarding the
questions, all mothers used them in a similar proportion, but those who made
the questions for the blind were preferably related to "What is...?" and for the sighted to "yes/no."
Thus, although the functions of
the emissions of the two mothers were quite similar, Kekelis and Andersen point out
that the language directed at the blind was more directive than that used when addressing
to the other child. Furthermore, as we studied on the previous pages, the use of
imperatives and the absence of affirmative and negative questions seems to cause delays
in the acquisition of the auxiliary forms of verbs in speaking blind children
English
On the other hand, it should be noted that the mothers of blind children started the
conversation and chose the topic of it more often than those of the
seers, which is consistent with the blind child's problems calling and
share attention on objects. Such topics focused on 50% of the
occasions, in the child's own feelings and activities and when they referred to
other people, events or objects, these belonged to the child's immediate environment.
Despite this, almost half of the topics introduced by the mother of the blind child are not
they were based on the objects that the child was perceiving, since they were things that
They were near him but at that moment he was not touching or hearing.
We do not intend to discuss here to what extent the language of parents influences the
characteristics of blind children. As the reader knows, we start from the
based on the interaction that occurs between the baby and
his mother since the early stages of his life. In this sense the
previously mentioned investigations reveal that the two members of
the communicative dyad adapt their emissions reciprocally and that the forms that
they adapt to the perceptual characteristics of the child. Thus, by
For example, we have seen that adults talk to children about their own actions like this.
as well as the objects they have nearby. Likewise, the mothers of the visually impaired
they introduce the topic of conversation more frequently than those of the seers, in front of
the difficulties their children have in doing so. However, few conclusions.
we can contribute to the reader regarding the suitability of the communicative style of the
mothers studied for the optimization of the communicative development of the visually impaired.
It seems that it would be necessary to use a less directive language, with a greater number of
affirmative and negative questions, that would give the child more opportunities to respond.
It also draws attention to the excessive use of tags and the scarce
descriptions of the objects used by these mothers. Precisely the difficulties
what the child has to know the objects and, consequently, to talk about them,
the absence of vision should lead to greater involvement of mothers in the interest of
those objects, interest that cannot be achieved through the use of mere labels. In
in any case, new longitudinal intervention work is needed that
investigate the possibilities
of well-trained mothers to optimize communicative and linguistic development
of blind children from the early stages of their lives to the final period of
acquisition of oral language.

2.5. The game

Despite the importance of play in human development, there have been

very few studies have been conducted on play behaviors in blind children. In addition,
most of those scarce publications adopt a differentialist stance of
agreement to propose studying the differences that exist between the game of
seers and the blind. Consequently, we have very few data to write
this section: the observations that, indirectly, provide us with the
research dedicated to the study of preverbal and verbal communication, the review
carried out by Warren in 1984, Parsons' contributions (1986 a and b) on play
with objects, Fraiberg's (1977) observations on the development of play
symbolic in the absence of vision and the work recently published in Spain by
Lucerga, Sanz, Rodríguez Porrero and Escudero (1992).
We know nothing about the exercise game that the blind child performs during the period.
sensorimotor. Without a doubt, the problems of accessing objects that are located outside
of the environment that they can reach with their hands, hinder exploration and play. For
what refers to the child-adult interaction games that occur in the so-called
stage of 'primary intersubjectivity', the research of Junefelt, Preisler and
Urwin, which was referenced in section 2.3, collects the existence of this type of
games in the child-adult dyads studied by them. As already mentioned, the mothers who
those involved in this work had a high level of information and interest in it
development of their children, so they interacted with them more than one might.
habitual among the mothers of other blind children. It was about rhythm games and
songs with physical contact initiated by their own mothers.
We have pointed out in previous pages the difficulties that blind children have to ...
establish the game rules child-object-adult that, according to Bruner,
characterize the second half of the first year of life. As we know, in the absence of the
vision, children have trouble constructing object permanence, about
everything to know that there are those who are beyond their reach. Likewise
we know the difficulty that the child has in getting the attention of adults
through alternative means to the visuomotor gestures of pointing. Although we have not
found no data in the literature we assume that, despite these difficulties, has
if there is any kind of shared game with objects, whether with those that are next
to the child, or with any other that the mother provides, thus initiating the interaction.
We are undoubtedly facing a topic that needs to be investigated in depth. Since
our own point of view, the data we have analyzed about the acquisition of
language in blind children seems to indicate that it fulfills a role from the very beginning
very important function in the development of blind children. Thus, in the absence of the
conventional gestures used by sighted children, the blind can use their
first verbal emissions to demand objects and to initiate "a conversation"
with the adult over them. In relation to this, Urwin (1983) points out that since the
start of her study with Suzanne (at 15 months), the girl and her mother "were talking"
about an object," even if they did not engage in a joint play activity with it.
object. However, until the age of 27 months, the girl was unable to offer objects.
to her mother, after having been trained to do so. And it is precisely from
At this age, the author observed an increase in shared play between the two.
Parsons (1986), in a study on the differences in the use of toys
among the children with low vision and the sighted, made certain observations that have
what to see regarding the topic at hand. The visually impaired children aged 2, 3, and 4,
they spent much more time than the seers interacting with their caregivers,
trying to draw their attention to share the objects.
But the role of language does not remain only in the possibility of demanding the
attention
of the adult. As mentioned in section 2.2, auditory imitation can replace the
visual in the construction of the first signifiers by blind children.
Likewise, the deferred imitation of the conversation sequences that occur
In the daily life of the blind child, they constitute their first manifestations of play.
fiction. Thus, the various authors who have studied the functions that are fulfilled by the
frequent repetitions, imitations, and routines that characterize children's language
the blind, agree in stating -more or less explicitly- that, often, these
imitations become games of fiction. As we will analyze below,
when a child does not have the ability to imitate sequences of daily life that they cannot
visually perceive, resorts to mimicking the conversation patterns that occur
during those sequences. Precisely the repetitions of verbal emissions that the
blind children communicate outside of a context and were considered
by some authors as behaviors
deviated and non-functional, seem to be for others (Dunlea, 1984; Mulford, 1989; Pérez
Pereira, in press; Pérez Pereira and Castro, 1990 and 1991) the first manifestations
delete
fiction game with role swapping. In this sense, we interpret the data
obtained by Lucerga et al. (1992), according to which the telephone is the toy
What else do blind children like, and calling on the phone, their favorite game.
The data we have on the fiction game (mainly coming from the
work of Fraiberg, 1977, some others collected by Warren in his 1984 review, thus
as those by Lucerga et al., 1992), point out the delays and problems they have
blind children to carry out this type of games. For example, Fraiberg observed that
approximately at the age of two, when sighted children begin to
"imitating" domestic life by playing with dolls, the blind were completely incapable
to do it even if they were encouraged by an adult. Likewise, at two and a half years,
when the seers begin to represent themselves in the game, attributing to the
symbols -the dolls- their own activities. blind children did not carry out
no games of this type. Only between the ages of 3 and 4 did these children start to play
fiction games. moment that coincided with the acquisition of pronouns
personnel. Similarly, Lucerga and colleagues point out that children's symbolic play
blind and visually impaired individuals of normal intelligence develop with a medium delay
about 15 months when compared to that of the seers. If we analyze with
detaining the data collected by Fraiberg herself, as well as some of the
examples that provide us with studies on language acquisition, we can
reconstruct a sequence of game development in blind children. As
the reader can check, despite
of the alternative ways that these children have to use to simulate scenes of life
daily and the problems they have when using toys whose symbolism tends to be based on
visual similarities, such a sequence does not seem very different from that of sighted children.
However, it should be noted that all of these children had optimal conditions of
development within highly motivated families and therefore their achievements in games
Fiction cannot be generalized to all blind children.
At 18 months old, Jerry, one of the children studied by Urwin, reproduced, of
in a deferred manner and with a playful character, a conversational sequence in which
he represented with different voices the roles corresponding to himself and his father. This
sequence, which was used as an example of delayed imitation in section 2.2., is very
similar to other imitations, - usually of actions rather than voices - that they make
the sighted children of approximately the same ages who are considered as the
first manifestations of the game of fiction.
Fraiberg (o.c.) informs us of the following play sequence in a blind 3-year-old girl.
years old. Since it was about studying the development of symbolic play and that
the girl liked to bathe, Fraiberg and her collaborators prepared the toys
necessary for the girl to be able to bathe a doll. But instead of doing so, she
she herself introduced into the small bathtub full of water and began to develop the
next dialogue in which he simulated his own voice and that of his mother: "Swimming in the
water. "Mom, look at that." "Whee, vhee." "Don't you notice it?" "Very well, keep going" in the
water. "Very well, sit in the water."
Shortly after, the same girl spontaneously got into a sink (that she recognized)
as such), simulating that he was in bed and reproducing the dialogue that
he usually kept with his mother before going to sleep.
Without a doubt, in these two sequences we can talk about symbolic play since there is
use of symbols (objects that are given a use that they do not usually have) and
simulation of scenes outside the real context where they normally take place. No
however, this game seems to be somewhat more primitive than that of the sighted children
same age, especially in the aspect of decentration, since the girl was not able to
to represent herself through a doll.
At approximately the same age as Kathie, Sandra -the blind girl studied by
Pérez Pereira y Castro-- was playing with a "smurf", to which he said: "Umh, you don't want!"
«¿Quieres un yogur de mortadela? «¿Quieres un yogur? «¿Quieres un yogur al natural?
Although the authors do not explain the context and situation of the game, it seems that Sandra
reproduce a more advanced game in which it uses the doll as if it were a being
animated it was, with the girl performing the role that is normally carried out by the adult in the
daily life.
According to Fraiberg's data, Kathie, at four years and six months, was performing
games with her two dolls, playing the role of mother. She would give one of them the
bottle that she herself filled and closed, while she spoke sweet words to him:
"Do you want to give me a kiss?" "Goodbye." "Did you hurt your head?" (And he was rubbing it)
(to relieve the pain). "He is crying." "He wants the bottle." The author believes that
these games are similar to those of sighted children aged 2 or 3 years, although since
our point of view its integrated and planned character resembles more to those of the
children of the same age as Kathie. The ability to "pretend" that the blind girl had,
it was evident that at this same age, he had an imaginary friend to whom
called 'Zeen', with whom he maintained dialogues in two voices and to whom he attributed his own
mischief.
These data demonstrate that, as has been repeatedly said, in the absence of
The vision children have difficulties sharing their games with adults. These
Difficulties also entail others in the understanding of conversational roles.
which also seem to manifest in the symbolic play that involves role changing.
Thus, it seems to first arise in the imitations of everyday conversations and
only later evolves into a shared game with objects in
real conversations where the pronouns 'I' are learned to be used correctly
and "you". From this moment on, the blind child will begin to apply the changes of
roles in fiction games where one can represent oneself through elements
symbolic as they are the dolls and to the adult through their own action. The scarce
the data we have seems to indicate that, subsequently, the game of fiction of
blind children develop very similarly to sighted ones.
Analyzing the dimensions involved in symbolic play, Lucerga et al. assert.
that the substitution of objects, that is, the use of symbols, evolves in a manner
similar in blind and sighted people. The same does not happen in the dimension of decentering.
As we just said, until at least three years of age, it is very difficult that
blind children can shift their focus from themselves to place it on an object
symbolic. As for game planning, the data obtained by
these authors indicate that these children find it easier to plan the game than
execute it with which, again, the important role that has is made evident
language in the development of symbolic play in the absence of vision.
Finally, it is worth noting again that all research seems to indicate that the game
shared with objects is a necessary requirement for understanding the changes of
conversational turns, as well as for the child to be able to use symbolic elements
in the game to represent oneself and one's interlocutor. In any case, we are
on a very important topic where it is necessary to have new works of
research that allows for more solid conclusions. Such work must be
set aside the visuocentric perspective and study the alternative pathways used by the
blind child to develop his own fictional games.

3. The school stage

Most of the studies conducted with blind and visually impaired children in
ages between 6 and 12 years are engaged in studying various aspects
of their cognitive development. It is almost exclusively about research based
in the theory of Piaget and the School of Geneva which will be analyzed on the pages
they initially tried to verify the applicability of the theory for
explain the development of children who suffer from certain deficiencies or disabilities.
On the contrary, very little effort has been devoted to other aspects that are so decisive in the
development of the human being such as social relationships - the interactions with the
companions and with adults-, the evolution of personality, or the motivations of
children both inside and outside of school. Similarly to what happened in
the developmental psychology of 'normal' children between the years 1960 and 1980, both the
experimental works like the theoretical attempts on the characteristics
psychological aspects of school-age blind children have primarily focused on the
study of cognitive development. Therefore, publications are very scarce.
related to the non-intellectual aspects of children's psychological development
blind and visually impaired. Moreover, those publications are very far from the
interests of this chapter, as it involves works carried out from perspectives
differentialists and atheoretical. Thus, as the reader can find in the reviews
conducted on the subject in the books by Warren (1984) and School (1986), said
jobs usually only focus on confirming the differences existing among the blind
and seeing in various tests or scales of personality and socialization without attempts
explanations of why such differences exist and without providing solutions for the possible
problems encountered.
Consequently, in this section we will focus on the study of the
cognitive characteristics of blind and visually impaired schoolchildren. Undoubtedly, there
They need research that analyzes such important aspects in the development of being.
human as social relationships, the characteristics of personality, or the
motivation. As has been demonstrated throughout the reading of this chapter, the
the child's interactions with the beings around him are decisive for his optimal
development as a human individual. In this sense, it is important to take into account that,
although the predominant activity of the child between 6 and 12 years old is learning
school and the development of their intelligence, these cannot, in any way, be studied
separately from the social interactions that occur both inside and outside of school,
neither of the motivations that the child has. Undoubtedly, for blind and visually impaired children
Visuals should be as important or more so than for the sighted. Establishing good...
relationships with peers, parents, and teachers. Likewise, as has been
proven in the studies conducted with psychics, the expectations that the
parents and teachers have about the development and learning capacities of the
Blind people must largely determine the implementation of such abilities.
It has already been said at the beginning of this section that almost all of the research
made on the cognitive development and learning of deficient children
visuals in the school period, take as a reference Piaget's theory and the school of
Geneva. As the reader knows, such theory advocates the existence of a sequence
universal development, which occurs over three major periods or stages:
sensorimotor, concrete operations, and formal operations. Consequently, their
authors are interested in demonstrating the homogeneity of ontogenetic development in
the different cultures and in the different individuals and, of course, do not accept the
possibility of alternative development pathways for children who have
any kind of disability. In any case, delays are predicted for these children and
problems in achieving the "universal" stages of development
intelligence.
On the other hand, it is well known that, for this development theory, the origins of
Intelligence is not in interaction or language, but in actions.
sensorimotor actions that the child performs with objects from the early stages of their
life. Therefore, although Piaget and his closest collaborators never did
research with deaf or blind children, the predictions about the development of the
the first were much more encouraging than those made for the visually impaired, such
as evidenced by the following quote:
Language, in effect, is nothing more than a particular aspect of the semiotic function or
symbolic and the deaf-mute perfectly masters its other aspects (imitation, play
symbolic, mental images and gestural language), which allows it to extend its
sensorimotor schemes into representative schemes and thus reach operations
before the blind man, whose sensorimotor schematism and figurative instruments
suffer a greater deficiency." (Piaget, Grize, Henry, Meylan-Bakcks, Orsine and Van
Den Bogaert-Rombouts, 1966, p. 70 of the Spanish edition.
Undoubtedly, one of the objectives of this section is to compare development capabilities.
and learning of children with different sensory disabilities. As it has been going
repeatedly throughout the pages of this book, the deaf and the blind
they cannot be considered homogeneous groups in any way since, to the factors of
variability that affects the development and learning of all human beings, there is
to add those related to the different etiologies of the deficiency, as well as
the effects that it produces on the people surrounding the child throughout the
different stages of his life. On the other hand, as it has also been said, such a comparison
would be contrary to our own theoretical position. The interest in the study of the
sensory deficiencies is not about determining, much less, whether the absence (or the
decrease) of the visual or auditory channel produces greater or lesser delays in the
achievement of
the Piagetian stages of development. Nevertheless, we must not deny the
peculiarities that exist in the learning and development process for the blind
like in the deaf. On the contrary, it is about studying the pathways carefully.
alternatives that can be found in development in the different forms of impact
visual and auditory, in order to establish the mechanisms of 'remediation' more
suitable for each case.
We are not going to delve into the peculiarities of the development of deaf children here; the reader
Anyone interested in this topic can consult the manual by Marchesi (1987). In the case of the
the blind believe we can affirm that the outlook is not so bleak as
predicted Piaget. The analysis carried out so far on the early stages of life of the
blind child highlights, on the one hand, that the absence or deterioration of the channel of
The collection of visual information does not prevent the formation of sensorimotor schemas.
Certainly, for a blind baby it is more costly than for a sighted one
knowledge of objects and the space that contains them since the systems
senses that replace vision - touch and hearing mainly, are less
appropriate
that it is for such a task. However, despite the difficulties, the child will eventually finish
to know those objects and that space through the sensory systems available and,
Undoubtedly, it will manage to construct images of such objects. On the other hand, we have been able to
also check that the blind baby has alternative non-visual pathways for
relate to people, show your 'affection' towards them, as well as to
establish the first forms of communication, as long as adults are capable
to understand
and to respond to those non-visual forms of communication in a culture like ours,
in which the preponderance of the visual system for preverbal communication even
verbal, it is undeniable. Of course. we cannot overlook the difficulties that for
the child has, in the absence of vision, to establish preverbal and verbal communication with
adults about objects. As already mentioned, these difficulties arise from a
side, of the fact of having to know objects through different sensory systems
to the vision and, on the other hand, the difficulty that finding gestures represents for the child
alternatives to visual signaling that are understood by their family members. It is
It is also important to highlight the fact that the blind child has to
build the significants of their first symbols through non-visual imitations.
As we pointed out on previous pages, since the blind child starts to emit
his first words, everything seems to indicate that language is constituted in a
important tool capable of "remediating" many of the problems arising from the
lack of vision.
Precisely, as we will see below, the work on development
cognitive of blind children in the so-called stage of "operations"
concrete" also reveal that they can use different routes to resolve
the tasks inherent to this period with the same efficiency as the seers. With this
we want to say that, if the development and education conditions of the blind child are
Hello, there should be no problems arising from the use of this form of the
thinking, although to reach the same results as the seers the blind person may have
to use different routes. Furthermore, and similarly in contrast to the hypotheses
Piagetian, this type of work highlights the importance of language in evolution.
of the intelligence called 'concrete'.

3.1. Intellectual development

It was Ivette Hatwell, in an excellent book published in 1966, the first author who
studied, from the Piagetian perspective, the characteristics of cognitive development
of blind children in the so-called stage of concrete operations. Just as she
the same statement in that book, the research on the cognitive development of the
subjects who have never had the opportunity to see, constitutes a magnificent "test" for the
Piagetian theory of development. It tests the relative role of action.
sensorimotor --which according to their own statements is not nonexistent in the blind, but
which is hindered by the perceptual characteristics of touch, in contrast to the
what language fulfills --which, for Hatwell, remains intact in blind children-, in
the Piagetian stage of concrete operations.
As the reader knows, for Piaget concrete operations are internalized actions,
reversible and characterized by a set structure known as
"grouping". They do not derive, consequently, from language, but from action.
sensorimotor that, once internalized in thought through images, is
makes it reversible, and allows the child to 'operate' with objects that are not present but instead
"represented". The
operations do not arise in isolation in a child's thinking, but are grouped together
in that structure of a set which, formalized in the language of logic, has the
characteristics of a 'grouping'. Thus, the classic tasks whose resolution represents
the typical thinking of a child between 6/7 and 11/12 years -conservation, classification,
sequences, etc.-, have the same logical structure and, consequently, the same level
of difficulty, so all should present the same difficulty for everyone
subjects.
A detailed reading of Hatwell's work makes us think that, despite the
time in which it is written, in which the criticisms of Piaget's theory of development do not
had begun to emerge, the deep knowledge that this author reached about the
psychology of blindness, placed it in a critical position towards some of the
basic assumptions of such theory. Although at the beginning of his work, Hatwell does not assert
explicitly the problems posed by trying to explain the development of the blind
within the Piagetian theoretical framework, however, the hypotheses of his work are not
totally in line with the logic of the aforementioned theory. As noted below, such
hypotheses predict the existence of 'mismatches' in the acquisition of the different
operations by the visually impaired, and attribute a role to language
considerably greater than that given by Piaget and his collaborators in the genesis of
the operations of concrete logic.
More specifically, Hatwell's hypotheses predict, first of all, that children
the visually impaired will be delayed compared to the sighted in operations that are based on
figurative type structures - the so-called infralogical operations of space
and time-. This delay should be due to the lack of the visual system causing a
decrease in environmental stimulation and, consequently, of the images or
figurative representations. Secondly, shorter delays are predicted in the
logical mathematical operations (classifications, seriation, etc...) that, for Hatwell-
not for Piaget-, they depend more on the level of language development. For
Finally, within the logical-mathematical operations, the author predicts that the blind people of
birth will perform worse in tasks that are carried out with material
manipulative, in those others that have a verbal content or a presentation
oral.
The subjects chosen for the research were blind children, aged
aged between 5 and 11 years, mostly with early blindness, without
associated deficiencies. These children attended special schools for the blind and, in the
50% of the cases resided in these centers. The seers who formed the groups of
They were children attending public schools in Paris. In some cases, the
seers were divided into two groups, one of which (V.V.) carried out the tasks in
the normal visual conditions, while the other (V.T.) worked behind a
screen what forced him to do the tests with touch.
Hatwell considers "infralogical operations", two types of problems quite
different from one another. Some are really the same ones that Piaget considered as
infralogical operations of a spatial nature, while the others are the tasks
classical studies that examine the genesis of physical invariants, that is, those of conservation
of the substance, the weight, and the volume. As expected, the results obtained by
The blind in these two types of tasks are quite different from each other.
The two tests used to evaluate the infralogical operations of a spatial nature
They were, in our opinion, quite complex, as they addressed the knowledge of the
projective spatial relationships (left-right, front-back) that are established
among several objects. In the first of them, called 'displacement in two
dimensions", the child had to anticipate the positions that the different parts would have.
an object, when it was moving in a specific direction. The second,
rotation around an axis consisted of anticipating the position that would be taken by the
different parts of a composite object when it rotates around its horizontal axes
and vertical. As Hatwell expected, the performance achieved by the blind children in
both tests were considerably worse than those of the seers (both those who conducted the
tasks with touch like those done with sight), with a significant delay
regarding these last ones, which ranged between 4 and 6 years.
As for the conservation tests, the results are more encouraging.
for the blind. The delay of these individuals compared to the sighted ranges from 2 years, for the
conservation of substance and 3 for weight and volume. However, one must take into account
keep in mind that the sighted subjects of Hatwell seem more advanced than other groups
of subjects studied by other authors, both in weight maintenance and of
volume, since 70% of 9-year-old children maintained their weight and 45% of those
10 I did it with the volume. The author in question discusses extensively in her book the
causes of this delay in conservation by blind children and,
finally, it attributes it to the fact that conservation operations pose
problems that are more of an infralogical nature than purely logical. Specifically, it considers that
a certain way of spatial composition is involved in the conservation of the
quantities" (1. Hatwell, 1966, p. 75 of the English edition).
The study corresponding to the 'logical operations' analyzes in depth the
performance of the blind and sighted in operations that can be considered more
characteristics of concrete logic: classifications and seriations. According to the
hypothesis, the author divides -setting aside Piagetian orthodoxy-, these
operations in 'figurative', those that involve manipulation of concrete objects and
"verbals," those that have little or no figurative support and whose content is
essentially verbal. Consequently, the author compares the realizations of the
blind in equal operations, classifications and seriations, varying the material of the
the same ones that in some cases will be figurative and, in others, verbal.
For Hatwell, classifications are the core of conceptual thought and of all
cognitive activity. It states that deaf children have considerable difficulties in
to acquire them because of the role that language plays in the formation of categories. Thus,
It wonders whether perceptual factors have any function in resolving this.
type of tasks. Regarding the serializations, the author asks herself the same question, having
Keep in mind that such operations, unlike classification ones, are asymmetrical.
ordered, that is, the position of any two elements is not interchangeable
within the series. The tasks used in the
study of classifications and series, as well as the main results obtained
for blind children.
Of the two tests that deal with studying classification operations with
manipulative or 'figurative' support, the first is a classic Piagetian task
called 'discovery of the classification law based on perceptual contrast'
(Piaget and Inhelder, 1959). It is about the child discovering which of the elements of a
series differs from the others and specify what the reason for the difference is. The
The test consisted of four series, in each of which different ones were used.
classification criteria: shape, texture, size, and orientation. The results,
completely aligned with the initial hypotheses, showed that blind children
they solved the series with an average delay of between three and four years compared to the
seers who used vision, although this difference became less pronounced in children
blind children of 10 years (the oldest in the sample). It is important to highlight that
the performance of the other group of seers (V. T.) was intermediate, falling between that of
the blind and those with V.V., as well as the late blind obtained better
results that are early. For our part,
as we will explain later when commenting on the data obtained in our own
research, we believe that such results are not applicable to all the
manipulative classifications. They are precisely due to the nature of the test in the
that, as Hatwell herself states, the structuring of the material facilitates the
understanding of contrast when perceived visually (Figure 4.1).
The second of the manipulative tests is a simple additive classification.
called 'classification of geometric shapes and change of criteria'. The material
consists of eight wooden pieces, two cubes, two spheres, two flat squares and two
flat discs. Of those eight pieces, four were large figures and four small ones. Thus
It is possible to classify them according to three different criteria: shape, size, and thickness.

FIGURE 4.1. Material used by Hatwell (1966) in the test called

discovery
law of classification by perceptual contrast.

The results are also consistent with the hypotheses of the work, although in this case, the
the delay of the blind compared to the sighted was two years, less than in the task
previously reviewed. On the other hand, the results obtained by the late blind
they were better than those of the precocious and, on the contrary, no differences were found
between the two groups of seers. If we consider the tasks of verbal classification, such
as Hatwell had predicted, the results of the blind children were better. The
the first of them: "discovery of laws based on semantic contrast" is
structurally identical to the one already described about perceptual contrast. It was about
to discover which of the four words presented verbally had a meaning
distinct from the others as well as naming the classification criterion. In terms
In general, the results of the blind and the sighted were similar. They were also similar in
the second of the verbal tests consisted of the typical task of 'inclusion of
classes and quantification of inclusion" (Piaget and Inhelder, 1959).
In the study of serializations, Hatwell obtains results very similar to those that
we just described. It carries out a classic task of additive seriating taken from
Piaget and Inhelder (1959) as an example of manipulative seriation. The test consisted of
of three different subtests: cube series, rod series, and weight series. All the series
were made up of seven elements that, in the case of cubes and rods, had a
growing size. In the series of cubes, the material consisted of 7 boxes of the same
size that varied in its weight constantly. The results showed that the
the performance of the blind was lower than that of the sighted in the serial ordering of cubes and
rods, with a delay of between 1 and 3 years compared to these. On the contrary, when it.
I was trying to weigh things, the results of clairvoyants and blind people were very similar, without
that there was no kind of delay for the last ones. In none of the three
serialization problems resulted in differences between congenital and late blind individuals,
between the two groups of seers. For the author, these results confirm the
hypothesis that the visual configuration of the task -as occurs in the sequencing of
sizes - harms their resolution by the blind. This hypothesis is justified
Also, if we compare the performance achieved by these subjects in the task of
weight conservation and in the weighting seriating.
To study verbal character serializations, Hatwell uses classic tasks of
"transitive verbal series", also called "series of three terms",
using height as a comparative term (e.g. "Juan is taller than Pedro"
Pedro is more
under which Antonio", "Who is the tallest?" In this case, the results of the children
blind children aged 8, 9, and 10 were better than sighted children of the same ages, although
the differences were only significant when comparing the eight-year groups. Our
the author discusses these results highlighting how strange it is
that the blind individuals at the same age level are able to solve
correctly problems such as those involving verbal seriations, while
they have difficulties making some classifications and serializations. As we will see
Following the study of the conclusions of the work, the fact that the blind
they acquire almost simultaneously the operations carried out with manipulative material and
those that have support
verbal, leads Hatwell to consider that language can be an alternative way for the
construction of concrete thought by the blind.
Before presenting the definitive conclusions of his work, Hatwell discusses his
results in relation to three important uncontrolled factors and that, according to
with their own statements, they could have influenced them: motor problems
associated with blindness, school delay, and the simultaneous presentation of the material
manipulative along with the subsequent verbal.
Although Hatwell believes that blindness does not necessarily entail problems.
motors, the importance given by Piaget to action in the development of intelligence, the
leads to analyzing - or rather to dismissing - the possibility that these issues are the ...
causative factors of the delay of the visually impaired in spatial and manipulative operations.
Thus, on one hand, it argues that the possible motor deficiencies do not explain the
differences found in the resolution of manipulative and verbal tasks. On the other hand,
it exposes the fact of the children included in its sample, with blindness caused by
retrolental fibroplasia and motor problems caused by prematurity, no
they obtained results different from the other blind people. For our part,
we agree with Hatwell in stating that the characteristics of operational thinking
The blind children's issues are not explainable by motor problems. As we analyzed the
At the beginning of this chapter, we cannot say that there are special difficulties in the
motor development of these children.
As for school delay, the problem is more complex and difficult to
analyze. There is certainly a significant educational delay in blind children who
Hatwell places it, on average, in two or three years. The author notes that such a delay coincides
with the results obtained in his work on the acquisition of concrete operations and,
although it is not fully defined on this matter, it rather considers that the cause may be
the cognitive problems. However, it does not rule out the hypothesis that the
School delay could be related to the issues posed by mastery of
Braille reading and writing system.
Finally, the impact that they can have on the results is analyzed,
perceptual characteristics of the blind. The author highlights the fact that the
the achievements of these are very close to those of the seers in the tasks that
they involve a successive presentation (sequencing of weights and verbal tests),
precisely because both tactile and auditory perception are sequential in nature,
in contrast to the simultaneity that facilitates visual perception. We will delve deeper
later, when reviewing the data related to our own research,
in the important role that the characteristics of tactile perception have when it comes to
explain the peculiarities of the development of blind people.
Finally, let's move on to analyzing the conclusions of the work that concerns us. First
Hatwell emphasizes the fact that the most important problems arising from the
lack of vision are in the construction of the notion of space, although also
involve considerable difficulties in understanding the physical operations of
conservation, as well as in logical operations - classifications and seriation - that
they have manipulative material. Specifically, the comparison of these results with the
obtained in the verbal tasks, leads Hatwell to express the importance that it has
language in the development of the blind, the difficulties that Piagetian theory faces
find to explain such development and, consequently, the possibility that -
using my own terminology, there are alternative pathways for development in the
children without vision.
According to Piaget's theory and the Geneva School, operations with material
manipulative must precede the verbal ones within a certain time frame, just as
it occurs in sighted children. However, in the blind, both are acquired almost
simultaneously what, for Hatwell, suggests that verbal operations can
to develop relatively autonomously, even when there is a great
deficiency in those made with concrete material. Although the author thinks that -
At least in the initial stages of development, language cannot compensate for the
figurative deficits derived from tactile perception, it can indeed allow you certain
operability. Consider that the blind person, using conventional and accessible signs
what language provides him, can act on reality without having to perceive it
directly. Thus, the author believes that there may be other paths for development.
different from those indicated in Piaget's theory and that it is likely that the blind person will use
language as a way to access thought. 'The seeing child seems to develop his
logical potentialities mainly through activity with real objects
when he is little, while the blind person has to develop those potentialities
"mainly logical through the world of conventional signs" (1. Hatwell, o.C.,
p. 131).
We will revisit these important statements at the end of this section, once
reviewed the works done by the other authors in relation to this same
theme.
From our point of view, the problems that Hatwell's work raises for theory
Piagetian development resulted in his book having very few repercussions in the
work of the authors of the School of Geneva. Probably for this reason, most of
the research on the development of the visually impaired that take as a starting point
The works of this author have been completed by English-speaking authors.
initial works, published between 1969 and 1976, focused only on replicating
some partial results of the mentioned research, trying to find new ones
factors that explain the delay of the blind in operational tasks - especially in
the conservation ones. Only later, in the 1980s, are they found in the
general literature works that aim to verify and complete the results more
important findings obtained by Hatwell, focusing mainly on the importance it has
the tactile system in the peculiarities of the development of the visually impaired, as well as in the role
what language has when providing alternative paths to such development.

3.2. Social integration, schooling, and development

The first works that emerged from Hatwell's work dealt with
search for new explanations for the delay of the visually impaired in some tasks
studied by the author. Thus, as we will see below, it was the data related to
the conservation of the most replicated physical quantities, being "very scarce or
null the jobs related to logical and infralogical operations.
As the reader knows, the blind children studied by Hatwell were enrolled in school.
special centers and, since 50% came from the rural environment, resided in them
boarding schools. In addition, these children began their schooling two
years later than the visionaries, which is why they had a considerable school delay
regarding these. In contrast, the seers who acted as control groups,
they resided in Paris, attended public schools and, generally speaking, had no delays
school. Consequently, the authors cited below thought that the
the causes of cognitive delay in blind children studied by Hatwell were not due to
the blindness itself, but to the particular characteristics that the children had
blind to their work.
In this line lies the work on substance conservation carried out by
Cromer in 1973. He considers that the results obtained by Hatwell may be due to
the different origins -rural or urban- of the blind and the sighted as well as school delay
of the blind individuals studied. The blind children who participated in their research
they came from the city of London, where they attended a special school for
blind people, which we assume, although Cromer does not explicitly say so, that these
children did not reside at the school, but with their own families. The sighted children
that acted as control groups (one performed tests with vision and the other with
the touch), came from schools in central London. He found no differences between the
three groups of subjects in the age of conservation acquisition, neither in the type of
responses given by the children. Therefore, it concludes that blind children can have a
cognitive functioning similar to that of sighted peers of the same age, as long as
proceed from a similar background and have begun schooling at the same time
age. In this sense, the author discusses the importance that language can have in
contraposition with the visual input, both in the understanding of physical invariants
what conservation entails, as in the overall development of operational thinking.
Higgins, in 1973, conducted a study on classification operations.
in blind children. The experimental subjects were selected very carefully,
discarding those who had academic delays or some kind of problem
associated with blindness. The results showed no signs of delay in
the blind in relation to the sighted, which leads to the conclusion that blindness in itself
It does not cause intellectual problems. Thus, the author attributes those found in other works.
like that of Hatwell-, to a poor selection of the sample.
Other authors thought that, possibly, the main factor responsible for the
differences obtained by Hatwell between blind and sighted children would be living in or not
of the family environment. This would mean that the cognitive deficiencies found
in blind children, it should not be done -or it would be done to a lesser extent- due to the lack of the channel
visual, up to the affective and cognitive deprivation that comes from living in a
institution. In this sense, they also criticize Miller's (1969) research, which
attributes the delay of the blind children studied by her to the importance that it has
vision in the development of conservation behaviors, without taking into account that their
subjects lived outside the family environment.
Fue Gottesman (1973 and 1975), one of the authors who analyzed the incidence of the
variable 'living in an institution' in the understanding of the invariants of substance, weight and
volume by blind and visually impaired children aged between
the 4 and 12 years. He used two groups of blind children and one of sighted children. From the
First, some lived with their families and attended public schools, while others
others were educated in residential schools for the blind. Blind children from
children aged 4 to 7 years old achieved worse results than the sighted ones, while
that there were no differences between both groups in the ages between 8 and 12.
He also found favorable differences for the blind who lived with their families in the
group of the smallest. From this, it concludes that vision and visual images do not
are necessary for the conservation tasks, and can be replaced
through touch and tactile images. It also concludes that the fact that children
the blind are well integrated into their families and are considered as children
before being like blind people is a fundamental factor for their proper psychological development.
Brekke, Williams, and Tait (1974) also studied the incidence of the variable that
we analyzed the understanding of weight conservation. In this case, the subjects were
blind and visually impaired children aged 6 to 14 years, all of whom are considered blind
legal. The results showed that there were no differences between the blind children who
They lived with their families and the seers, as both resolved the tasks of
weight maintenance at 9 or 10 years old. The other group of blind individuals, on the contrary,
he only achieved these results between the ages of 13 and 14. However, the
The results obtained by the first group of blind individuals cannot be attributed solely to the fact
that they lived with their own families but also that, coincidentally, they were the ones
they had greater residual vision. As it is logical, the existence of visual remnants facilitated the
carrying out the conservation task, although the authors claim that the results
obtained in the same by the blind children who lived with their families, were
better than those of institutionalized visually impaired individuals.
Us too (Ochaíta, Rosa, Huertas, Fernández, Asensio, Pozo, and Martínez)
we studied in 1988, the incidence of the type of schooling and, to a certain extent, the factor
"institutionalization," in the development of blind children in the Piagetian stage of the
concrete operations. Our subjects were blind children from birth (or with
very early loss of vision), who were enrolled in regular schools
Madrid and therefore lived with their own families. A control group was
made up of sighted children who attended class alongside the blind and who had their
same age. The results obtained by another group of children were also used.
blind in a previous work (Rosa, Ochaíta, Moreno, Fernández, Carretero and Pozo,
1986). These subjects, also blind from birth or early onset, were educated in
the educational centers that ONCE had in Madrid and, for the most part, resided in the
institution, many of them coming from outside this city. Of course, the
the fundamental objective of the work was not merely the comparison between the two groups of
blind in order to try or not to verify the suitability of school and social integration.
It was solely about completing the data available on the development.
cognitive abilities of blind children to verify our hypotheses about the
same.
We will delve deeper into the data of this work in the next section of this.
chapter and, for the moment, we only offer those related to the topic that we are now
occupies. In general terms, we can say that our results confirm the
existence of a gap between the figurative and verbal in cognitive development of the
blind, as had been found in previous research (Hatwell, 1966;
Rosa et al., 1985). Non-institutionalized blind children achieved better
results that attendees at special centers, only in those tasks
related to verbal thinking in which the seconds had not arrived at
optimal results. More specifically, this occurred in the qualifying tests
multiplicative and conservation of substance, where blind children obtained a
performance quite similar to that of seers of the same age. On the contrary, in
the operations most loaded with figurative or spatial aspects, the results of the
two groups of blind individuals were quite similar and inferior to those of the control group
seers.
As for conservation tasks, our results are more than
agreement with the research of Cromer and Gotesman as well as that of Hatwell. In the
conservation of substance test, the integrated blind children, obtained
results somewhat lower than the sighted in the first age level studied (6, 7, and 8)
years), although the differences were not significant enough at the level
statistical, with the two groups becoming more similar at ages 9 and 10. This makes us think that
The understanding of physical invariants cannot be considered as problems.
very loaded with figurative or infralogical elements, but probably they
relate -or can do so in the absence of sight- to verbal aspects.
From the research reviewed so far, we can conclude that the lack or the serious
decreased functionality of the visual channel does not have to hinder, by itself
the same, the understanding of the problems involved in conservation testing and
of classification. In this sense, we believe that, in general terms, both types of
tasks can be considered more related to verbal aspects than to
others of a figurative or spatial nature. However, it must be taken into account - and that can
explain extensively that the results obtained by different authors are not
always coincident-, which probably in both conservation tests as,
above all, in classification tests, the testing material that is used and even the
The way it is arranged may be more or less accessible for analysis.
through touch. Thus, for example, the same type of problem, such as the
discovering a classification criterion can be particularly complex
for the blind if it is a criterion of spatial orientation. On the contrary if the
used is the texture or the shape, and even more the belonging to a certain category
linguistics, the difficulties of the visually impaired will be few or none.
When we say that blindness itself does not have to cause disorders in the
we are, of course, referring to a child of concrete logical thinking type
blind or visually impaired person who does not have other associated physical or psychological problems
to blindness. Thus, the prototype of a blind child that we can consider normal is one that
who, like the seer, is integrated into his family and social environment and, consequently
lives with his parents and siblings and studies at a regular school, if possible the
same as their siblings and neighbors. Regardless of the results obtained in
the various tasks of concrete operations or in other cognitive development tasks, it is
It is undoubted that the best thing for the blind child is to be integrated into the society in which
live. In this sense, we believe that education in special schools and even more
residence outside the family environment can seriously affect development
psychological development of the child and impact their social integration.
Finally, we must not overlook the important issue of school delay of the
blind. As has already been mentioned, some authors believe that such a delay is the cause
the poor performance achieved by some blind children in certain tasks of
concrete operations, while others believe that they are the problems
the intellect of these children is what causes their school problems. For our part,
we think that the peculiarities of the development of the blind do not have to
to create school problems. However, we cannot hide the fact that -to
except in our country-, it has been confirmed that there is academic delay in children
blind and visually impaired individuals from the middle cycle of primary education. Thus, although currently
In Spain, these children are educated at the same ages as sighted children, whether they...
they attend regular schools as well as special schools, later it is very
It is common for delays to occur in accessing higher school levels. A
study recently conducted by us in collaboration with the O.N.C.E.
(Fernández Dols, Fernández Lagunilla, Huertas, Maciá, Mateos, Montero, Ochaíta,
Riviere and Rosa; 1991) with a large sample of blind and visually impaired children.
integrated into the ordinary schools of the national territory, highlights that the
40% of schoolchildren aged 8-9 years, 52% of those aged 11-12, and 74% of those aged 13-14
has at least one year of school delay. More specifically, of the children who are older
age included in the study (13-14 years), 43% had one year of delay, 16% two and
12% managed to have three. The results of this work show that such a delay does not
it should be attributed to intellectual problems resulting from visual impairment. For a
part, the average scores of children in IQ, assessed using the verbal scale
of WISC were completely normal. On the other hand, the results obtained in the
Piagetian tests of concrete operations can also be considered normal.
for a sample of blind and visually impaired children, there being no indicators of
cognitive delay. Thus, we suggest that the most important cause of school delay
it can be in the difficulty that blind and visually impaired children have in the
access to written language. As extensively analyzed in another chapter of this
volume, the Bbraille reading and writing system presents serious difficulties for the visually impaired in
access to written language, especially due to the slowness and sequentiality of the
tactile receptors. Most of the studies conducted on reading and the
writing using the Bbraille system agree in confirming the existence of delays and
difficulties in the acquisition and mastery of reading and writing skills by
blind and visually impaired children. The reader interested in delving into this topic
you can refer to chapter 6 of this same book. Thus, for example, the results
obtained in the study just cited (Fernández Dols et al., 1991), highlight
I manifest the existence of significant difficulties in blind and visually impaired children.
visuals in access to written language through the Braille system.

3.3. Discrepancy between figurative and verbal thinking

Let's now analyze the research conducted in the 1980s.

on the development of the blind during the Piagetian period of concrete operations.
As we already said, these are considerably extensive works in which studies are conducted
the general characteristics of intellectual development in the absence of the visual system and in
those who analyze the possible explanations for its peculiarities.
Our own research group from the Faculty of Psychology at U.A.M.
has carried out, between 1980 and 1988, extensive work on cognitive development
of the blind in the school and adolescent stage. Taking as a starting point the
Hatwell's work (op. cit.), we tried to test the validity of Piagetian theory.
to explain the development of blind children and adolescents, as well as the hypotheses of
Hatwell on the discrepancy between the figurative and verbal aspects of thought. Thus
the early investigations tried to delve into the operations of a character
figurative -mental images and spatial operations-, dedicating ourselves afterwards
to the analysis of logical operations.
Hatwell's work had highlighted the existence of a significant delay
in the figurative thinking of blind children. That is precisely why the objective of
our first research (Rosa, 1980 and 1981), consisted of studying the development of
mental images in the absence of the visual system from the perspective
Piagetian (Piaget and Inhelder, 1966). We started from the hypothesis of the existence of
tactile images, but we also assumed that this perceptual system, having to
collect environmental information in a fragmented and successive manner would be less
appropriate for visualizing and maintaining that information in memory.
Work was carried out with almost all of the school-aged blind children.
special education centers of the O.N.C.E. in Madrid, for ages between
the ages of 7 and 15 years and without associated deficiencies. We must verify that, on the date in
that the research was conducted, most of the blind children were educated in
special centers for this type of disability and many of them resided in such
centers, as they come from outside the city of Madrid. On the other hand, a good number
these children were studying with a delay of one to three years compared to
the seers of the same age. Two control groups were also used.
seers, one of them had their eyes covered in such a way that they performed the tests
with touch, while the other worked under normal vision conditions. For
control the variables related to living in an institution and school delay, the children
participants from the control groups resided in an educational center of the Diputación
Provincial of Madrid, they came from quite disadvantaged families and often had a
delay similar to that of the blind in accessing different educational levels.
A series of six tasks were adapted to the perceptual characteristics of the blind.
concrete-, which were considered representative of the theory of Piaget and Inhelder about the
mental image. The results revealed the existence of a delay
important, about four years old, in the figurative development of the
the blind when they were compared to the sighted who could use vision. Not
However, it is worth noting the fact that the seers who conducted the tests
through touch they obtained results similar to those of the blind in most cases
from the tests. This means that the figurative difficulties of blind children do not
can be attributed to an intellectual delay resulting from blindness, but rather to the
problems derived from tactile perception. On the other hand, the delay of the blind is
canceled in the age group of 11 and 12 years, precisely in the considered period.
as the beginning of hypothetical deductive or formal thinking.
Subsequently, and following the recommendations suggested by Hatwell herself (op. cit.)
In the conclusions of their book, we set out to study the development of operations.
basic spatial skills in blind children (Ochaíta, 1982 and 1983). Thus, four were chosen
tests that were considered representative of the three types of spatial relationships
studied by Piaget: topological, projective, and Euclidean (Piaget and Inhelder, 1947).
The subjects, blind and sighted, were chosen following the same criteria of the
previous research, both in terms of age and school background
and social.
As expected, the performance of blind children on spatial tasks was
much lower than that of the clairvoyants of his own age who took the tests using
the vision. Thus, the delay ranged from four years for the most spatial relations
simple -the topological ones-, and the six or seven for the more complex ones -projective and
Euclidean-. However, it is important to note that the blind managed to achieve
correctly, at the last age level (14 and 15 years), even spatial tests
which, like the projective ones, are extremely difficult in the absence of vision.
More specifically, they were able to understand that the 'perspective' of a group of
objects change when the point of view of the observer does. Just like in the
research on mental imagery, also in this the performance of the blind was
very low in the first two age levels (between 7 and 11 years), occurring.
in the third or in the fourth (depending on the spatial problems involved) a
important evolutionary leap. Finally, it should be noted that the seers who carried out the
tests with eyes covered produced results similar to those of the blind, about
everything in the most complex tasks.
In conclusion, these two studies coincide with Hatwell's - and also with
Piaget's predictions about the development of blind children, in the existence of
a significant delay in the acquisition of figurative intelligence.
However, as has already been said, the results obtained by the seers who
they conducted the tests with touch, leading one to think that it is the fact of having to take
the figurative-spatial information with this perceptual modality, and not some kind of
inherent cognitive delay due to blindness, which hinders the performance of the blind.
On the other hand, the developmental profile obtained by these subjects in the two investigations
reviewed seems to mean that, at a certain moment in development, at the thresholds of
adolescence, access to a form of linguistic thinking or
Propositional can "remedy" the difficulties caused by sensory deficiency.
Finally, to complete our hypotheses about the gap between the figurative and
verbal in the cognitive development of the blind, a fairly extensive study was conducted
exhaustive about logical operations, which included various classification tasks and
sequences, both manipulative and verbal in nature (Ochaíta, Rosa, Moreno, Pozo and
Fernández, 1985; Rosa, Ochaíta, Moreno, Fernández, Carretero and Pozo, 1986). Also
In this case, the subjects were early blind individuals, without associated deficiencies, who received education.
in the O.N.C.E. centers of Madrid and Seville for ages between 6 and
the 14 years. The two control groups of psychics also came from the centers
assistance from the Provincial Council of Madrid. Later, in 1988, we repeated
the research with a group of blind children and another of sighted children with different
educational and family conditions. In this case, both blind children and the
seers lived with their own families and attended ordinary educational centers in
the area of the Community of Madrid.
Some of the characteristics perceptive to the blind were chosen and adapted.
most typical tests related to classification and seriation operations (Piaget and
Inhelder, 1959). Specifically, there were five different classification tests -
additive classification, quantification of inclusion, hierarchical classification,
multiplicative classification to be completed and spontaneous multiplicative classification-, and three
simple or additive seriating, multiplicative seriating, and verbal seriating
transitive-.
The first of the tests "additive classification" was similar to the second of the tasks.
of manipulative classification carried out by Hatwell. The material was made up of
for eight geometric figures that the subject had to classify according to three criteria:
shape, size, and thickness. The children had to find the maximum number of criteria of
classification. In contrast to the data obtained by Hatwell, we do not
We found no difference when comparing the results of blind and sighted children.
No differences were found between the different studied groups in the two
class inclusion tasks - 'quantification of inclusion' and 'classification'
hierarchical, which were easily resolved from the earliest age levels. Perhaps
It is important to note that, although in these two tests a reference was taken as a
concrete material that the child had to explore, the questions and answers of inclusion
classes were presented verbally, using the quantifying terms 'all',
«algunos», «ninguno», etc..
The different results obtained by the blind in the two tests of
multiplicative classification deserves special attention. According to Piaget and
Inhelder (1959), multiplicative classifications are more complex than additive ones.
since the
logical point of view, however, the figurative-spatial support that it provides
perception of the multiplicative matrix can help children solve them.
A first test of "completable multiplicative classification" was precisely chosen.
with a large figurative base. As shown in Figure 4.2, the material was formed
for a wooden box with four compartments, three of the four are already
arranged by the experimenter, starting the matrix. The child had to choose from among
other elements necessary to complete the classification. The development profile
obtained by the blind in this test was similar to what they showed in the
space tests and mental imagery. The children corresponding to the first two
age levels (from 6 to 10 years) obtained very low scores and
significantly lower than those of the sighted groups, while at 11 years,
In the third age level studied, the results of the blind and the sighted matched.
another task of multiplicative classification, which we call 'classification'
"spontaneous multiplicative" has, from a Piagetian perspective,
the same structure as the previous one and therefore, the same difficulty. However,
precisely by not having the matrix started, the child has to understand the problem without
that the spatial configuration of this matrix facilitates it. In front of a material formed by
16 geometric figures divided into 8 squares (4 large and 4 small) and 8 circles
(4 big and 4 small), the child must understand for themselves, without being initiated into the
task, that each and every one of the elements to classify belongs simultaneously to
two classes, in our case form and size. The results show that this test
it is much more difficult than the previous one for both groups of seers, since in the
The first two age levels achieved very low returns similar to those of
group of blind people, so there are no differences between the scores obtained by
some and others. It seems, therefore, evident that the results obtained by the blind in
the first of the multiplicative classification tests is not due to problems
cognitive issues arising from the lack of the visual channel, but rather that the tactile perceptual system
it does not allow them to benefit like the sighted, from the perceptual configuration of the
matrix. That is why, when that perceptual configuration does not exist, blind and sighted people
They have similar problems to solve the task logically.
Finally, let's analyze the data related to the serialization tests. The first,
"simple seriation" consists of the classic task in which the child must find the
asymmetrical relationships that exist between a series of eight rods of increasing length.
The results obtained by the blind in this task were extraordinarily
low if compared to those of sighted children of the same age. Blind children of
the first age levels were totally incapable of performing the task, while
that the youngest psychics solved it without any kind of difficulty. Again, the
the evolutionary profile of the blind is similar to that obtained in figurative tasks
spatial. The performance is very low in the first two age levels and, on the
At 11 years old, in the third level, there is a great leap that equalizes their results.
with those obtained by the psychics. Similar results were obtained by the deficient children.
visuals in the test of 'multiplicative seriation', in which it was about conducting the
series taking into account both the criteria of length and thickness. On the contrary,
when it came to performing verbal serializations, such as in the 'three series' test
"terms", no differences were found among the three groups studied.

FIGURE 4.2. Material used in the test of 'multiplicative classifications to

complete.

Once again we must attribute to touch the results obtained by the blind in the
manipulative series. While the vision allows the child to obtain a
global perceptual configuration of the series, when the blind child carries it out with the
Touching the perceptions of the material must be fragmentary and successive. This,
probably implies a greater load on memory and, consequently, an
greater difficulty in taking the test.
It is important to mention the results obtained by sighted children who
they worked with their eyes covered in all our investigations. We can say that, the
The fact of having to take the information in a tactile way decreased.
notably the performance of the psychics in the figurative character tests and
spatial, in such a way that, in the most complex ones, their results were similar to those
of the blind. In the less complex and/or more familiar tasks, the sighted people with the
eyes covered -just like the late blind studied by Hatwell-, obtained a
average performance between the sighted who used vision and the blind. This seems to
confirm the hypothesis that Juurmaa formulated in 1973 about sensory transposition:
when tasks are familiar to the subject, they can "transpose" the information
taken with the touch to visual images, through which it becomes easier for them
solving a figurative task. This does not happen, as we have already said, when it comes to
resolve unfamiliar or complex tasks, in which the seers who worked with the
touch obtained results similar to the blind. From our point of view, these
results cannot be explained solely by the lack of experience that they have
seers to conduct tests with touch, even if that is a factor that does not
we can disdain. The characteristics of tactile perception have been analyzed
extensively in chapter 3 of this same book, so it does not seem appropriate to us
repeat them here. In any case, the results obtained by the blind seers
they confirm the hypothesis that touch is less suitable than sight for gathering the
figurative and spatial information. Consequently, everything seems to indicate that it is the
The fact of having to collect such information with the haptic modality responsible for the
delay of the blind in tasks that contain this type of information.
We will return to this topic at the end of this section, once analyzed the
investigations by Stephens and Grube.
These American authors published the results of extensive work in 1982.
in which they studied the acquisition of the most representative tasks of the period of
concrete operations - and also the formal ones as will be analyzed in the section
dedicated to adolescence-, in a total of 150 blind and sighted children and adolescents.
Half of the sample was made up of early blind individuals and the other half by
seers, divided into three age groups: 6-10, 10-14, and 14-18 years. All of them
they had a normal intelligence (with an IQ of between 90 and 110 on the verbal scale of
Wechsler). The blind children came from different states of the Union and the authors
They do not specify the type of education they received. The seers attended schools.
public tasks in the State of Pennsylvania. The tasks were taken from a battery of
Piagetian tests developed by Simpkins and Stephens in 1970 for the evaluation of
the blind. In the case of specific operations, 10 tasks were used
conservation, 6 of classification and 4 of mental images and understanding of relationships
spatial. The conservation tests were as follows: one-for-one exchange,
term-to-term correspondence, preservation of liquids, preservation of the
length (2 tests), preservation of the substance, sugar dissolution (substance)
dissolution of sugar (volume), conservation of weight and conservation of volume. The
classification included: intersection of classes or multiplicative classification, inclusion
of classes, three classification tasks that are not specified and change of criteria
classification. Finally, the figurative and spatial tests consisted of: rotation of
accounts, square rotation, change of perspectives (mobile) and change of
perspectives (stationary).
To evaluate the development of the blind, Stephens and Grube compared the results.
obtained by the groups of 6-10 and 14-18 years. They found that the scores of the
older subjects were significantly taller in all tests except for
three of the figurative: account rotation, square rotation, and change of
perspectives.
When comparing the total results obtained by blind and sighted individuals without taking into account
the authors find significant differences favorable to the age
forecasters in the two tests of number conservation, in the conservation of the
length, weight, and volume, in three of the classification tasks (multiplicative, inclusion
and changes of criteria), as well as in all matters related to figurative problems and
spatial. Therefore, blind and sighted individuals only achieved similar results in the two
tests of substance conservation, conservation of length with beads, and in
three of the classification tasks that the authors did not describe. The results were
very similar when studying the performance of both groups by age levels. Thus, in
a total of 26 tests (including those corresponding to the
formal thinking), blind and sighted children aged 6 to 10 differed from
significant form in 14, those aged 10-14 in 14, and adolescents in 17. The differences
they were always favorable to the seers, except in three qualifying tests where it
they were for the visually impaired of the youngest group, as well as in another task of
classification in which blind adolescents achieved better results than the
clairvoyants. In any case, it is important to note that the major difficulties of the
blind spots occurred in tasks related to spatial orientation and images
mental.
From these results, the authors reach conclusions in line with the theory.
Piagetian development. They argue that the lack of vision, by restricting interaction with
The subject with objects and people causes severe deficiencies in reasoning.
logical. Nevertheless, they believe that such problems could become smaller
providing blind children with more opportunities to interact with their environment
physical and social.
Undoubtedly, the results obtained by the blind in the research by Stephens and
Grube presents a much more pessimistic outlook on development in the absence of
the vision that those from Hatwell and those from our own group at U.A.M. As we have
said, if the results of the blind are analyzed independently, there is a
clear evolution throughout the three age levels in most of the variables
studied (excluding three of a figurative spatial nature). However, when one
they compare the results of blind and sighted individuals, there are differences favorable to the latter
last in more than half of the tests, differences that -in contrast to
Our own results remain consistent across the successive age levels studied.
Consequently, the development sequence in the absence of the vision obtained by the
cited authors do not reflect a clear increase in adolescents' ability to
resolution of the tasks of concrete logic. These results, as we have already said,
differ from those obtained in our research and, to some extent, oppose
our own theorizing about the role that verbal thinking may have or
hypothetical deductive in the cognitive development of the blind.
There are several hypotheses that we can offer to the reader to explain the differences.
between our own results and those obtained by Stephens and Grube. But first, it is
It is important to note that we have not been able to delve as deeply as we would have liked.
in the work of the cited authors. We only have a summary article in the
that, due to the extension of the original investigation, aspects are not described as much
decisive in the performance of the blind such as the content and the material of the
tests corresponding to each of the studied variables.
Thus, in the first place, the results may be due, in part, to the type of tasks used.
Although, as has already been said, in the article published in 1982, Stephens and Grube did not
they describe exactly what each of the tests consists of, they refer us to a
battery developed by themselves to assess the reasoning of the blind. Such
The battery contains, from our point of view, a good number of tests that, due to the
type of material used, can pose figurative and spatial problems to
to be carried out through touch. Furthermore, the very act of using tests
standardized can cause additional problems since the 'tests', although they
they do it individually, they do not allow to obtain so much information about the children - and more
even when it comes to blind people - like the purely clinical interview method. For
finally, the type of subjects -both blind and sighted- used in the work, could
also have some influence on the results. Blind children and adolescents
they came from different States (as we have said this is a job
North American) and, since the authors do not specify what type of schooling
they received, it may be the case that among them there are those who resided in schools
special. On the contrary, the sighted subjects attended public schools and resided
with their own families. As was made clear in section 3.2 of this same
chapter, in some cases the school and family conditions of the
blind and not necessarily the lack of vision, those responsible for the low performance
of these when comparing the seers.
In any case, it is important to note that the direction of the results is similar.
like the other works on the cognitive development of the visually impaired. Also
the blind children studied by Stephens and Grube had greater difficulties in
solve the concrete operations related to figurative and spatial problems
than those of a more verbal nature. In relation to this problem, and alongside the
general conclusion about the cognitive deficit of the blind, the authors hypothesize that
next:
Thus, it could be said that blind people have the potential for development.
operational, but they face difficulties in their evolution. The basis of the difficulties
They can be figurative. That is, with visual perception, two objects can be explored.
at the same time; with tactile perception exploration is successive" (Stephens and
Grube, 1982, p. 137.
To conclude, despite the results of this last work, we believe it is possible to affirm
that blindness itself does not have to cause serious problems in development
cognitive in the concrete operational period. What actually happens is
that the lack of the visual channel produces characteristic delays in the acquisition of the
concrete logic. Everything seems to indicate that, as Hatwell stated in 1966, the lack of
vision and the fact of having to take in information through touch creates a "sequence
evolutionary characteristic. Touch, sequential and slow, is much less appropriate than the
view to collect figurative and spatial information.
Consequently, as can be seen in figure 4.3, an important
discrepancy between verbal operations and figurative-spatial operations of concrete logic
in blind children. A gap that, in most cases and as we will see in the
next pages, seems to overcome in adolescence thanks to the remediation that
provides formal or hypothetical deductive thinking.

FIGURE 4.3. Results obtained by blind and sighted individuals in the figurative tests
verbal actions carried out by the research team of the U.A.M.

3.4. Learning and cognitive development

We do not want to finish this section dedicated to the school stage without offering the reader the
scarce data available in the literature on the effects of training on the
intellectual development of blind children. This is also the case of
operational learning investigations that, in general, use a procedure of
learning close to that initiated by Inhelder at the school of Geneva (Inhelder, Sinclair
by Bovet, 1974) and in which the effects of learning on problem-solving are studied
various specific tasks.
The two initial studies (Friedman and Pasnak, 1973; Lopata and Pasnak 1976), take
as a reference point the work of Hatwell. Just like in the research
commented on in section 3.2., they also aim to review or complete some of
the author's results. In both cases, it was about getting the blind children
they surpassed the delays they initially had compared to their peers of the same age,
in conservation and classification tasks.
Lopata and Pasnak (1976) carried out a quite intensive program of
training in various aspects related to the conservation of substance.
The subjects were 28 blind children, aged 8 to 13 years, residing in a school.
especially that, in the pretest of conservation of substance and weight, they had given responses
non-conservatives. The 14 children in the experimental group received 25 sessions of
45-minute learning sessions each, which included measurement problems, sequencing,
classification and conservation of the substance. The control group -also formed by
14 blind children received an intellectual enrichment program that included
various activities such as playing with the materials used by the group
experimental, tutoring, etc.. The results obtained in the post-test showed that the
children in the experimental group increased their scores significantly
both in the conservation of substance and weight, while this did not happen in the
control group.
For their part, Friedman and Pasnak (1973) used a training procedure
in classification tasks, quite similar to the previous one. The 16 blind children who
the sample were initially evaluated with a pretest that included a
a considerable number of classification problems. They were subsequently divided into
two groups, one experimental and the other control. The former received a program of
learning that included different manipulative and verbal classification problems; the
second received a program of intellectual enrichment. Also in this case the
the training was effective, as the experimental group improved considerably
more than the control group's scores in the post-test, equaling those of sighted children
his same age.
Stephens and Grube (1982) also conducted a wide-ranging program of
training in specific operational tasks that constitutes the continuation of the
research described in the previous section. As is common in this type of work,
they used two groups of blind people, one experimental and the other control, each consisting of
one for 13 blind matched by sex and age. From each group, 8 came from schools
residential and 5 public schools. All of them were early total blind, without
associated deficiencies, aged between 6 and 18 years and with an IQ of between
90 and 110 on the Wechsler verbal scale. A control group was also included.
sighted individuals formed by children of the same sex and age as the blind and attendees of schools
public. All subjects were divided into three age groups: 6-10, 10-14 and 14-18
years.
In the pretest, the same concrete operations tasks described in the
previous section (phase 1), plus another 6 of formal reasoning. The sessions of
intervention, lasting 45 minutes, took place three days a week over two
school courses. These sessions were adapted to the profile previously obtained by each subject in
the different tasks. The learning procedure was the typically used one in the
Geneva school. Thus, the professors who led the intervention sessions were
trained to: allow the child to make their own discoveries, based on
the child's own actions and thoughts and create reasoning situations that
require the interaction of this with objects and people.
The results obtained in the pretest were similar to those of the first phase of the
research. The scores obtained by the seers were significantly
higher than those of the experimental group of blind individuals in 15 of the studied variables, and to
the blind in the control group was 19. The experimental group of blind individuals obtained
better results than the control in three tasks: mental images, relationships
spatial and account rotation. Once the training phase is completed, it
they eliminated the differences that previously existed between the blind people in the control group
and the seers in eight tasks of conservation and classification, in one of space
(account rotation), as well as in three formal operations. However, the
seers achieved better results than the blind in two tasks
figurative/spatial (rotation of squares and stationary perspective change) and in
a formal test heavily loaded with figurative and spatial aspects:
transfer from two to three dimensions. The experimental group of the blind was superior to the
control in 17 of the 26 tests performed. When the scores were compared
obtained before and after the training, the results show that the blind who
they did not receive training, their performance only increased in 8 of the tasks, while
that those belonging to the experimental group did so in all variables except in
four: two figurative-spatial and two classification (in which an effect occurred
"roof".
These results obtained after the training program are interpreted
by the authors as a confirmation of the conclusions of the first phase of their
work. Thus, they believe that blind children have the necessary potential to acquire
a normal capacity for logical reasoning, but lack the necessary experience
to develop it. In this sense, they advise that these children engage in activities of
learning that allows them to interact with objects and, consequently, develop
its logical capabilities.
Ultimately, the data we have on the acceleration of the development of logic
concrete in blind children, allow us to conclude that it is possible to enhance such development
through specific training procedures. As we have already established
manifesto, the group of blind children cannot be considered as a group
homogeneous since a good number of distinguishing circumstances converge in them
that produce sequences of development more or less slowly. Without a doubt many of these
children, due to their specific family and educational conditions, have had less
learning opportunities that sighted children usually have. This
lack of opportunities, along with the restriction of interaction with the environment that,
logically, it entails a lack of vision, which can lead to delays in the resolution of
certain specific tasks. Thus we agree with Stephens and Grube that it is
It is necessary to provide blind children with the maximum opportunities for action and
interaction that provides them with an appropriate experience with their physical and social environment.
But these opportunities should be provided, whenever possible, within the
natural context of development-learning of these children. What we mean by
this means that the stimulation of the development and learning of blind children must
starting from early childhood with training programs for parents and
educators. Subsequently, the work should continue, promoting to the fullest the
school and social integration of these children. From our point of view, only in the case
that the children would not have had this type of opportunities and, as a consequence,
seriously lack action and interaction experiences, it would be advisable the
use of training programs aimed at accelerating development
logical reasoning.
In this regard, we consider that the research programs aimed at
stimulating the learning of blind children should focus on those areas of
cognitive development and/or school learning in which the lack of vision
constitutes a serious problem. As all the studies have shown up to
Here analyzed, the fact of having to take information with touch poses to the
blind people face considerable disadvantages in understanding figurative problems and
spatial, disadvantages that remain even after certain learnings.
As we will study in chapters 5 and 6 of this same book, dedicated
regarding spatial knowledge and braille literacy, the deficiency
visual poses specific -and often serious- problems in these two areas. The
mobility and adequate spatial knowledge are necessary to achieve that the
visually impaired individuals can integrate more easily into school and society. Reading and the
writing is absolutely essential for school learning and as
we will see in the corresponding chapter, the execution of these processes through the
Touch produces important problems. All the research reviewed throughout
this section 3 has shown that touch, slow and sequential originates
problems in processing and recollecting complex and/or figurative information.
It is these same characteristics that cause problems in access to the
information written by the blind. We will revisit these issues in the
corresponding chapters, here it is only a matter of pointing out that these are the areas
priorities that must be directed -during the school period- the special programs
of learning.

4. Adolescence

Adolescence is the stage of human development that follows puberty and is

characterized by a series of physical and psychological changes -affective, social and
cognitive - very important. Puberty leads to profound changes in the
body image of boys and girls who accompany transformations no.
less important in personality, in motivation as well as in relationships
affective and social relations they maintain both with their own peers and with the
adults.
Important changes also occur in the way of thinking and solving.
problems that in turn influence and shape adolescent personality. We are not going to
enter here into the analysis of the characteristics of adolescence, which have been
thoroughly studied in seers. The reader interested in delving into the topic
you can consult the excellent book published in 1985 by Carretero, Marchesi and
Palaces. Undoubtedly, the transformations that occur in the body after the
puberty causes the young person's body image to change significantly and rapidly,
moving from childhood to adulthood. Therefore, he is in the situation of accepting his
new motor and sexual capabilities, which has a significant effect on him.
psychological with an increase in self-awareness and interest in one's own body,
In addition, the development of intellectual abilities will allow him/her to reflect on himself/herself.
the same and about others, criticize the family and social models in which one lives and
formulate hypotheses about different forms of life: All this will, in turn, cause
the motivations of adolescents change and they often become more interested in the
care of their own image and for the relationships with their peers rather than the tasks
that adults consider more important and necessary, such as the
schoolwork.
Precisely because of all the changes that occur in this stage of development, both
popular beliefs like most psychological theories about the
adolescence agrees in stating that it is a period prone to conflicts
personal - problems of acceptance of one's own body image, search for the
identity
etc.-, and to the social -generational problems that manifest within the family
or in the educational center, integration in groups or gangs, etc.. Despite the fact that some
authors believe that this stage is not, in fact, more conflictive than others in life
of the human being, the most widespread idea is that it is a problematic period.
Despite the importance that this stage undoubtedly has in the development of the
blind people, as can be seen in the reviews on the subject carried out by Scholl
(1986) and Warren (1984), there are very few works that rigorously study
the incidence of blindness in the emotional and social relationships of adolescents.
Scholl believes that adolescence can be a particularly difficult time for
the visually impaired. As we know, this is a period in which young people
they are organized into groups or gangs that are defined, among other things, by their
homogeneity in aspects such as dress style, gestures, language, etc.. For
Scholl (op. cit.), blindness can prevent the adolescent from following or imitating the patterns of their
group and, consequently, the integration within it. According to Kent
(1983), the problems of self-image acceptance, group integration and
Relationships with the opposite sex tend to be more significant for girls than for boys.
On the other hand, the intellectual development that occurs during this stage allows for
the blind to reflect on their own problem which may lead them to reject their
own image, not to associate with boys of the opposite sex and, consequently, to
not integrating into teenage groups.
Undoubtedly, serious and rigorous work is needed to analyze the
psychological characteristics of blind adolescents. It is possible that - just as it has
noted in a review of studies conducted with psychics (Coleman, 1979) - the
adolescence is not necessarily a stage of life more conflictive than another
anyone,
as long as the blind teenager has had harmonious development and is in
well.
integrated into the family, the school, and society in general. In any case, just as
Mangold and Mangold (1983) assert that it would be very useful to have research in
those that base intervention programs to prevent possible problems that
can arise in boys and girls with severe visual impairments.
As we pointed out in the previous section dedicated to the school stage, also in
the one corresponding to adolescence has received greater effort in recent years
to the study of cognitive development and learning that relates to affective aspects
social. For our part, we have not found in the literature on the subject
recent research works that seriously analyze the characteristics of
personality of adolescents with severe visual impairments, their motivations or
their possible difficulties in emotional and social relationships. For that reason, we see ourselves
forced to reduce this section to the study of the peculiarities of development
intellectual of the blind.

4.1. Formal or abstract thinking

Research on the characteristics of cognitive development during the

adolescence also has its origin in Piaget's theory and the Geneva school
(Inhelder and Piaget, 1955). Within this theory, the period referred to as the
Formal operations constitute the final and most developed stage of thought.
human. At first, Inhelder and Piaget argued that such a stage should
to start between 11 or 12 years old and conclude between 14 and 15. Subsequently, they admitted
the possibility that the complete achievement of formal thought could be prolonged
until the age of 20. Likewise, they acknowledged the individual and cultural differences that exist
they are produced in the development of this way of thinking, as well as the role of the
experience in accessing the various operations of the logic called formal.
Like the rest of Piaget's works, the one dedicated to adolescent logic as well.
It has been the subject of numerous replies and clarifications. It is currently known that it does not
it deals with a universal stage of thought not even for Western adults
considered normal. Of these, only about 50% use thinking.
formal and they only do it in those tasks most related to their experiences
academic or professional. On the other hand, the different problems that must be
resolved by applying a formal or abstract logic are not homogeneous but rather present
different levels of difficulty. In addition, cross-cultural research has highlighted
I declare that abstract thinking does not have to be considered the ideal goal of
the intellectual evolution of human beings, although it undoubtedly serves the purposes
of Western scientific thought. In this sense, it is important to point out that neither
at least the young or adult Westerners who can reason formally before a
certain task, they often use such reasoning to solve the problems of the
daily life.
As a result, there are many difficulties we currently face to
referring to a stage of development based on the Piagetian construct of
formal thinking. However, we believe that studying the possibilities that the
The visually impaired may find it very interesting to use this type of reasoning.
since the topic is at the center of the controversy of the research on the
relationships between language and thought (Carretero, 1985). Although Piaget and his
collaborators
they made no predictions regarding the possibilities of formal reasoning in
the blind and deaf did indeed specify clearly the need for language
for such reasoning. In any case, the studies conducted on this matter usually
presenting itself as proof that language is a necessary condition -although not
sufficient - to access this way of thinking (Inhelder and Piaget, 1955).
Precisely the three aspects that characterize intellectual functioning during
this period is based on a reasoning for which language, or a way
Associated representation of this is essential.
Firstly, the adolescent would be able to conceive reality as a subset of
the possible, and to reason about the possible. While the child in the concrete period only
is able to think about the elements of a problem as they are in front of him,
a teenager who reasons formally can face such a problem having
It accounts not only for real data, but for all possible situations and causal relationships.
among the elements. Secondly, and precisely to reason about the possible, the
the adolescent will be able to use hypothetical-deductive thought that consists of
to propose possibilities through verbally stated hypotheses and to verify them
systematically through a deductive method. Lastly, in relation to the
previously, it is considered that the reasoning at this stage is propositional. This implies
that, in contrast to the children of the previous period who operated with the data
real or concrete aspects of the problem, the subjects of this stage can reason about
propositions, that is, using verbal statements as substitutes for that
problem. Consequently, language constitutes an important tool for
reason about the possible.
Let's now revisit the data discussed in the previous section in relation to the
Cognitive functioning of blind individuals in school age. As the reader knows, the
various studies conducted on this matter have revealed the existence of
a significant gap between tasks with figurative and verbal support. Both the
results obtained by Hatwell as those corresponding to our own team of
work allows us to affirm that blind people are capable of solving earlier the
concrete operational tasks of a verbal nature than those with figurative content, to
contrary to what happens in psychics and what could be assumed from the theory
Piagetian. Thus, we agree with Hatwell when he states that 'in the
establishment of operating systems, progress in the verbal sector
they probably promote the evolution of the concrete sector. To verify this hypothesis
It would be necessary to continue, over time, the development of blind children and determine if
The delays observed in concrete level are completely overcome in adolescence.
(Hatwell, 1966. Page 130 of the English edition, 1985).
Moreover, the results of our own research suggest that
some of the more complex concrete operations of a figurative or spatial nature,
can only be solved by the blind when they are able to use a form of
hypothetical deductive or formal thinking. This would imply that the blind could
to reach the most complex concrete operations of figurative-spatial content at
same time as formal operations, which again raises a serious
problem for Piaget's theory of stages. On the contrary, it could happen that
although blind people, upon reaching adolescence, were finally able to solve the
concrete figurative tasks in the same way as the younger seers, and not
we could talk about equal cognitive performances for blind and sighted people. In
in this case, the similarity between the performance of both could be due to an effect
"ground" and it would imply that by using the more complex formal operations tasks, the
The performance of the visionaries is superior to that of the blind of the same age.
Finally, and in relation to the above, it is important to study extensively the
development of formal thinking in blind teenagers to find out if in
during this period and in more complex tasks, the gap between tasks occurs again
manipulative and verbal, or if precisely the use of hypothetical thinking
deductive definitely allows for overcoming the figurative deficit that originates the
lack of vision. In other words, it is about finding out whether the use of touch for
collecting information related to spatial or figurative tasks poses problems that
They can only be resolved through higher-order verbal operations.
Despite the importance that this topic has for the psychology of blindness,
As for the formulation of general development theories, it has been very scarce.
interest that has been received from the researchers. We only have regarding this the
work of Stephens and Grube (1982), as well as those carried out by our own
research group (Rosa et al., 1986; Ochaíta et al., 1988; Pozo, Carretero, Rosa and
Ochaíta, 1988.
As mentioned in section 3.3 of this chapter, Stephens and Grube conducted in
1982 a comprehensive study on the development/learning of concrete operations and
formally a total of 150 blind and sighted children and adolescents of ages
aged between 6 and 18 years. They used 6 tasks of formal operations.
charges, just like those for specific operations, from the battery developed by Simpkins
y Stephens (1970). Specifically, three tasks related to conservation of
volume (conservation of volume, dissolution of sugar and dissociation of weight and
volume), one of combinatorics (the classic task of combining liquids), a
complex classification and a complex spatial task of transferring from two to three
dimensions. Their results showed that only in the combination tests
of liquids and classification, the performance of blind adolescents (14-18 years)
was better than that of children (6-14 years old). In the remaining four tests, the subjects
adults did not achieve significantly better scores than those of the
small. On the contrary, the results of the seers did improve significantly.
with age, although they may not reach the maximum scores. As a consequence,
When comparing the results of blind and sighted individuals, the former were found to be behind.
regarding the seconds in four of the six formal tasks used.
These results, along with those obtained by the boys aged 14-18 in the tasks of
concrete operations seem to indicate the existence of significant deficiencies in the
formal reasoning of blind adolescents. As has already been mentioned on pages
previously, the existence of such deficiencies would be in accordance with Piagetian theory
of development. However, if we analyze in depth -just as we did in the
section dedicated to specific operations-, the tasks in which the blind
they obtain lower returns, we think that the results are more in line with
our own hypotheses about the cognitive development of the blind. It is about
tasks whose understanding is especially complex for the blind for various reasons
reasons. On one hand, the space test (although it is not specified exactly in what
it consists), seems to pose a particularly complex problem when vision is lacking and
the information must be collected through touch (the task consisted of transferring the
spatial relationships involved in a representation from two dimensions to three
dimensions). As highlighted in chapter 6 of this same book, the
blindness brings with it a series of important difficulties in representation of
space, but also the understanding of the transition from a bidimensional representation to
another three-dimensional is essentially visual. Something similar happens with the tasks of
volume conservation. As we have mentioned on another occasion (Pozo et al., 1985), the
spontaneous understanding of the concept of volume almost necessarily requires the
visual observation of the water level displacement caused by the different
bodies. Therefore, if we set aside our 'visuocentrism', it will be easy for us
understand why the performance of the blind is considerably lower than the
of the seers in the different tests related to the understanding of this
concept
The results obtained by blind adolescents after the sessions of
training (see section 3.4 of this same chapter) confirms our own
interpretation of the data obtained by Stephens and Grube. These subjects exceeded
completely the problems they previously had in understanding the concept of
volume since its performance matched that of the seers of the same age.
On the contrary, the learning sessions did not allow the blind to overcome the
difficulties in space task precisely because it is a figurative problem
very complex space (even for the seers) and whose understanding through the
touch, it becomes practically impossible. Thus, when the aforementioned authors discuss the
results obtained in this task by blind adolescents affirm: "... the task
It had a strong visual component that apparently could not be translated into another.
task that required an execution based on the tactile component." (Stephens and Grube,
1982. page 141).
Therefore, the research analyzed so far does not allow us to conclude the existence of
reasoning problems in blind adolescents. For our part, we think more
although the tasks used by Stephens and Grube were not the most appropriate for
evaluate formal thinking in the absence of vision. The data obtained in our
own work (Rosa et al., 1986; Ochaíta et al. 1988), lead us to think that the type of
representational code that implies formal reasoning allows "to remedy"
many of the problems derive from the lack of vision, but not to replace it in tasks
for which it is essential. In this regard, it is important to point out the good
results obtained by the blind in the only classic task of formal operations
used by Stephens and Grube. As already mentioned, the combinatorial problem was
correctly solved by the blind in the preliminary phase of the investigation, without
that training was necessary for its performance to match that of the
psychics of their same age.
On our part, we carried out two extensive works on the development of
formal thinking in blind adolescents. The first (Pozo et al., 1985; Rosa
and col., 1986) aimed to verify our hypotheses about the peculiarities of
development of the blind, using some of the Piagetian tests
significant for the study of this stage of development (Piaget and Inhelder, 1951;
Inhelder and Piaget, 1955). More specifically, we aimed to verify whether the delay
manifested by the blind in some tasks of concrete logic had an effect on the
adolescent thinking and whether the gap between manipulative and verbal problems
it continued or not occurring in the domains of formal thinking. Consequently,
we also intended to know if the use of language as a tool for
remedy the figurative and spatial problems arising from lack of vision
produced in the blind a developmental sequence different from that described by Piaget and
their collaborators. More specifically, if the blind were able to understand and
resolve the figurative problems belonging to concrete logic to the same
ages that accessed formal logic.
The sample was composed of three groups of subjects: early-blind, sighted individuals who
they conducted the tests under normal vision conditions and - in the tasks
manipulative - seers with their eyes covered. The subjects were aged between
between
11 and 18 years old and were divided into 4 age levels. The 32 early blind individuals came from
from the O.N.C.E. schools in Madrid and Sevilla and they had no other deficiencies than the
lack of vision. The two groups of seers, each consisting of 32 subjects, were studying in
boarding regime in two schools of the Autonomous Community of Madrid. Both the
Blind subjects, like sighted ones, came from disadvantaged social backgrounds.
Two manipulative tests were used - a classic variable control task and another one.
of combinatorics - and three verbal - combinations, variations, and permutations. As
representative task of the scheme called 'variable control' we chose the
problem of the flexibility of the rods. The material, slightly simplified
regarding that used in 1955 by Inhelder and Piaget, it consisted of a support with a
small hole to suspend the rods, 18 rods that differed from each other by three
dimensions (thickness, length, and material) and 3 different weights equipped with a small
hook. Consequently, we had four variables, three of which were in the
stick and, for that reason, its effect could only be dissociated through the comparison of two
bars that differed from each other in just one of the variables. The fourth variable was weight and
its effect could be verified by exchanging one weight for another while maintaining
constants the variables related to the rods. It was therefore a situation
relatively simple multicausal in which it was necessary to analyze the action of each one
of the variables through the manipulation or control of the rest. The test, in which all
the variables that were used were relevant, it posed no conceptual problem
added, since the causal effects studied were quite intuitive and
well known to children and adolescents. However, the fact that the
Material should be explored through touch, which made the test have some
additional difficulties for blind subjects: blind children and adolescents had to
carefully explore the material and leave it organized on the table in order to
Remember at every moment the variables involved in the task.
On the contrary, the manipulative combinatorial problem did not pose any.
special difficulty when being explored by touch. Its structure is analogous
to the liquid combination test devised by Piaget and Inhelder (1955). Without
embargo, by not considering the material of such a test suitable for the visually impaired, one
an adaptation of the device devised by Delval (1986) was made to study the
combinatorial reasoning. The material consisted of a device of shape and
sizes similar to a shoebox, on top of which five had been placed
switches and a bell. The bell would start ringing when they were in position of
Switches number 1, 3, and 5 have been turned on. The switch number 2 is on.
it obstructed the sound of the bell, regardless of the position of the others
switches. Switch 4 was disconnected so it did not meet any
function. This test was basically used to study causal reasoning,
focusing on the kind of checks that the boys made to know and
explain to the experimenter the role each of the switches played in the
sound production (Pozo and colleagues, 1985). The task resolution required, just like
than that of the rods, the correct use of the variable control scheme.
To evaluate combinatorial reasoning with verbal material, a
adaptation for the blind of the section dedicated to combinatorics in the operations test
Longeot's formals. In reality, the subjects were required to perform three sub-tests of
combinatorial differences: variations, combinations, and permutations. The tests are
they carried out collectively using the braille system and without a time limit. The
The analysis criteria were developed following those established by Piaget and Inhelder.
in 1951 for equivalent problems (Pozo et al., 1985).
The results reveal, firstly, that in the period of thought
formally, there are no significant differences between the performance of blind subjects and
psychics in almost all tests conducted. As a result, we can
conclude that the lack of vision does not cause difficulties or delays in the ability to
reason in a hypothetical deductive manner.
In this regard, it is important to note that upon reaching adolescence, the visually impaired
they seem to overcome the problems derived from having to collect the information through
the touch in tasks of a manipulative nature. However, it should be noted that
in the rod test, the performance of the blind was somewhat lower than that of the
seers, although the differences between them never reached sufficient value in any case.
statistical. Everything seems to indicate, therefore, that there are no competition issues
in the formal reasoning of the blind, although undoubtedly, touch is less
appropriate
that the vision to collect -and keep in memory- information about a material
manipulative whose characteristics must be taken into account in order to carry out
systematic combinations. Imagine the effort that the reader must make.
blind person to memorize the position in which they have placed the different rods and weights
and to locate them using the hands, in contrast to the rapid exploration that
make the seer of the same material.
As for the verbal tests, the data showed a slight superiority of
the seers, which was only statistically significant in one of the three tasks and
only for one of the four age levels (specifically the differences between
blind and sighted individuals aged 15 and 16 in the problem of variations, resulted
significant at a confidence level greater than 5%). In any case, as has been
manifested in previous publications (Pozo et al., 1985; Rosa et al., 1986), the
scarce differences between the blind and the sighted can be attributed to collective achievement and
writing of these tests. Although the subjects had no time limit for
solving combinatorial problems, reading and tactile writing through the
The Braille system is much slower and more cumbersome than that used by sighted people.
Possibly, having to solve problems in writing may have affected,
certain extent, to the performance of blind subjects.

Table 4.5 presents the results obtained by blind and sighted subjects in the
different tests. The results obtained at ages 2, 3, and 4 have been
grouped to obtain the percentage of subjects who reached the maximum level of
response in each task. As can be seen, the results obtained by the blind
were somewhat lower than those of the seers in all tasks except in the
corresponding to the manipulative test of combinatorics, although the differences of
means between blind and sighted individuals of the same age levels have not been
significant (except in the case mentioned in the previous paragraph). Of course, the
the results obtained do not allow us to conclude that the blind have problems with
to reason abstractly.
On the contrary, they seem to have the same competence as the seers to carry out such
reasoning whenever the material provided to them allows them to act of
agreement with such competence.
Finally, it is necessary to point out that in all the tests, the most important progress is
it originated in the transition from age level 1 (11-12 years) to 2 (13-14). This jump occurred
in the three groups of subjects studied, although it was more pronounced in the blind by
generally starting from a lower initial level than the sighted. Everything seems to indicate,
As mentioned in the previous section when talking about concrete logic, upon reaching the
adolescence, the use of new hypothetical-deductive strategies allows to
the blind solve tasks that they could not solve until that moment. In
as a consequence, it is from the age of 13 or 14 when blind adolescents solve,
with the help of abstract thinking, not only the problems of formal logic, but
also those that by their figurative/spatial format are only concrete when
can be carried out with vision. As can be seen in figure 4.3, the blind
they solve concrete operational tasks of a figurative and spatial nature,
approximately at the same ages when they understand formal problems.
The results obtained in this first work led us to design another one with the
Objective of strengthening the conclusions about the cognitive development of the blind.
In this second work (Ochaíta, Rosa, Huertas, Fernández, Asensio, Pozo, and Martínez,
1988), we set out, first of all, to delve into the study of causal thinking and,
second, strengthen our data with research on another of the schemes
more well-known formal: proportional reasoning. In this case, the sample was
composed of a total of 32 subjects divided according to their age and level
educational at five levels, whose average ages were 8, 5, 11, 5, 13, 9, 17, and adults.
Approximately half of the subjects were early total blind.
the other half were severely visually impaired individuals commonly referred to as
"amblíopes". All the teenagers studied in the residential centers of the
O.N.C.E. in Madrid did not have associated deficiencies from blindness, while the
adults were teachers from those same centers.
The causal reasoning test -in contrast to those related to rods and to
switches that were described above - did not allow the subjects to
experimental manipulation of variables. In contrast, adolescents and adults
they faced the problem of determining what factors had produced
a certain fact or effect. Specifically, a test designed by Pozo was used in
1985, in which the subject was asked to discover which were, among various factors
proposed, those who cured a supposed disease called "ladiplaxia lubular".
All subjects took the test individually and received the following
instructions:
"In 1978, the existence of a serious disease was discovered in the USA, until then
unknown called ladiplaxia lubudular. The doctors did not know how to cure this
disease for which they treated the sick in various ways, all of them based
in a combination of four factors: taking vitamin pills, exercising
playing ball, getting some antibiotic injections and following a diet of
foods. After the treatment, they observed that some patients had recovered and others
No. We are going to give you information about some patients, some cured and others not.
try to tell us what makes them heal based on this data
patients.
Initially, we are going to give you information about four patients. Pay attention to it and tell us.
What do you think is the reason for the healing? If you need information about other patients.
subjected to different treatments, ask us for it. We have all the necessary.

TABLE 4.6.-First four examples of treatment presented to the subject

Sick 1

Sick 2

Sick 3

Sick 4

Sports Pills
Diet Injections

Sports Pills

Pills Injections

Sport

Healed

Not cured

Cured

Not cured

Next, four paper plates were handed to you, each of which

it corresponded to the treatment used to cure the disease in a specific
subject. Each dish presented a different combination of the four possible factors.
causals that were represented by the following objects: A candy tablet-
(vitaminas), una pelota (deporte), una jeringuilla (antibiótico) y un cubierto de plástico
(diet). The dish also contained an inscription in braille indicating whether the patient
whether they had been cured or not with the treatment. The four cases that were presented
Initially, they are collected in table 4.6.
Once the subject had studied all the cases, they were asked to say which one
considered the factor or factors that cured the disease and justified its
answers. He was also asked if he was sure that he had obtained a result
sure or yes, on the contrary, I needed new data from other cases to
find out. As the reader can verify, from this data it can be known that
the only factor that would always end the healing is the injections. However,
new data was necessary to discover the necessary factors for healing that
it could be produced through two distinct combinations: injections and pills or
injections and diet. Thus, the test was designed to uncover the two mistakes of
inference that is most commonly made: false inclusion (including the pills
because they are present in the treatment of the two cured patients) and the false
exclusion (excluding diet and exercise without considering that there may be effects
due to the interaction of the factors). If the subject said they needed more data, they were given
it informed that I could request the corresponding results from the experimenter
treatments based on all the combinations of factors that I wanted. Then the
the experimenter provided the dishes corresponding to the required factors,
as well as the result obtained with these. When the subject said to be sure of the
the curative treatment should be communicated to the experimenter and explained why it
It was considered this way. The analysis criteria used for clairvoyants were followed in the
research by Pozo (1985 and 1987).
The results obtained in the first part of the test showed that there was a clear
progress in the use of more appropriate causal inferences as it increased the
age of the subjects. First of all, the two lowest age levels used strategies
of reasoning based on their personal ideas, without taking into account the information that
they had about cured and uncured patients. Adolescents and adults, due to the
On the contrary, they were capable of using that information when solving the task. But
Important progress was also found in adolescent reasoning.
adults and adults regarding the group of 14 years: the latter resolved
predominantly the task based solely on one of the four cases presented,
whereas the former used all the available data in their reasoning.
In addition, younger adolescents used inclusion inferences (accepting the
the incidence of a factor on the outcome), and they were not able to use the exclusion one
(eliminate the impact of a factor on the outcome). On the contrary, the two levels of
adults made the same number of inferences of one type and another. If we compare
these results with those obtained by Pozo (1985 and 1987) in sighted subjects, all
seems to indicate that the evolution of the blind and visually impaired throughout the
different age levels is very similar to that of the seers. Moreover, the data
allow us to assert that the strategies used by the visually impaired are of the same type as
the ones from the seers.
It should be noted, however, that in the second part of the test there do seem to exist
differences in reasoning between our visually impaired subjects and the sighted
studied by Pozo in 1985. The number of blind and amblyopic individuals who completed this
The second part was smaller than that of the seers. These results are difficult to achieve.
explainable and, undoubtedly, require further research to determine if they are
caused by the conditions of the test application or if, on the contrary, there are
real differences between the reasoning of the blind and the sighted. It is very likely that the
the tendency of blind and visually impaired individuals to 'close' the task prematurely may
must, again, be due to the characteristics of tactile perception. Undoubtedly, it would have to
result in being slower and more cumbersome for our subjects to obtain the information about the
different treatments and their results through touch that for sighted people when taking
visually the information. In any case, the comparison between blind and sighted people.
it can only be considered approximate. As stated in section 3.2 of this same
chapter, the school and family conditions more than the visual problems, can
explain the differences between blind people and sighted people. Thus, it should be taken into account that the
sighted subjects studied by Pozo belonged to more advantaged social classes and
they conducted their studies in ordinary centers.
Finally, it should be noted that no differences were found between the results.
obtained by total blind subjects and those others with visual remnants. Such
results seem logical since, except for the tendency to close prematurely the
task, the strategies of causal reasoning do not appear to be related to the
visual experience of the subjects.
Let's now analyze the second of the formal thinking tests. It
treat
of the balance scale - one of the classic tasks devised by Inhelder and Piaget in
1951 - in which the subjects must use the scheme of double reversibility. This
it is assumed that the tilt of the scale depends on the weight that is
use and the placement of this more or less near the center of the scale. The
use of this thought scheme and, therefore, the resolution of this test,
it is one of the most difficult when we compare it with the rest of the typical tests
of formal thinking. Taking into account the characteristics of our subjects,
we chose the adaptation of the test described by Siegler in 1978. Such adaptation
allows presenting the problem in a simplified way and, as we will explain to
continuation, perform a more detailed analysis of the subjects' responses that the
original task by Inhelder and Piaget.
The subject was sitting in front of a double-armed wooden scale; each arm had
four pivots where the weights could be inserted (some plastic washers). The
the scale had wooden stops at the ends that prevented it from tilting
that they were withdrawn. Once the subject had sufficiently recognized the material
and I could predict what would happen when washers were placed on the outer pivot of
one side and none on the other, the test began. As can be seen in figure 4.4.
it consisted of eight items, in each of which the subject placed in the
different pivots a certain number of washers following the instructions of the
experimenter. Once the weights were placed, he had to anticipate the inclination of the
scale. Subsequently, the stops were removed and the subject had to verify the tilt
of the device. If this did not correspond with the previous response, they were asked to explain
what happened. The subjects' responses were analyzed and grouped into five levels
previously established. We will not dwell here on the description of such
levels; the interested reader can refer to the work of Ochaíta et al., 1988.
The results showed that blind and visually impaired subjects were making progress.
in the understanding of the rules of operation of the scale as
she was getting older. Likewise, they highlight that the exact understanding of the
the ratio between weight and distance is especially complex and was only
achieved by adult subjects. Adolescents aged 16 and 17 were able to
start to make compensations between weight and distance but in a way
qualitative, that is, without being able to establish systematic compensations between
the two factors through a quantitative relationship. Such results are very
similar to those described by other authors for sighted subjects, both in what refers to
refers to the rules used to solve the task as well as the evolution of them.
On the other hand, no
differences were found between the performance of total blinds and amblyopes, which
seems to demonstrate that visual experience does not seem to be necessary when
solve this formal thinking test.
4.2. Blindness, touch, and language

In light of all the work we have analyzed so far, we believe we can affirm
that there are no significant quantitative or qualitative differences between blind people and
"in the acquisition of formal thought. The congenitally blind are
capable of using this form of reasoning at approximately the same ages
that the seers, in a proportion similar to these and using similar strategies.
Thus, we can conclude that visual experience and sensorimotor actions
derivatives of this cannot be considered necessary to develop the
abstract thinking.

FIGURE 4.4. Items used in the scale test

Therefore, we can now state that, as was intuited in the corresponding section
at the school stage, the delay of the blind in concrete operations of a character
figurative and spatial is definitively surpassed in adolescence with access to a
form of verbal or hypothetical-deductive thinking. This comes to corroborate the
Hatwell's hypothesis that we referred to on previous pages: there seem to exist
alternative pathways in the development of blind individuals, according to which
The progress in the verbal sector promotes that of the concrete sector. As has been said.
several times throughout this chapter the interaction, communication, and language
they play a very important role in all stages of development for the blind. Thus,
Everything seems to indicate that the problems arising from having to collect by touch the
figurative and spatial information is resolved upon reaching adolescence by
means of higher order operations that allow the use of a code of
fundamentally linguistic thought. However, it is important to note that
although this type of thinking may remedy many of the figurative problems
derived from the lack of vision, does not replace or substitute this sensory system. With this
We want to say that although from adolescence the possibility of using a
The form of thought derived from language allows the blind to overcome the
most of the problems we encountered in previous stages, this does not mean
that they regain their vision. Blind adolescents and adults must continue to use
fundamentally touch as an alternative to vision for gathering information about
the external world, which implies a different experience of the world than that of the seeing.
In relation to this, we believe we can affirm that the very phenomenon of blindness
allows us to explain certain results discussed on previous pages, especially the
from Stephens and Grube. As already mentioned, most of the operational tasks
The formats used by these authors had a strong visual component, which made them
especially unsuitable for the blind. We have already said that the
spontaneous understanding of the concept of volume goes through visual observation of the
displacement of liquid caused by different volumes. Nevertheless, it is about
a perfectly understandable concept in the absence of vision if - as in the phase of
learning from the experiment we discussed - the blind person is provided with the experience
adequate. The same does not happen with the spatial task that involves the passage of a
two-dimensional representation to another three-dimensional. While a blind person can achieve
to understand through hypotheses what a two-dimensional representation means
for a seer, this does not imply that touch can precisely capture the change in
the spatial relationships involved in moving from two to three dimensions.
Touch also allows us to explain some characteristics in the thinking of the
blind people found in our own research. As can be seen in the
Table 4.5, the results of the blind in the verbal combination tests were -
contrary to what was to be expected - worse than those of the seers, although in general,
the differences do not reach statistical significance. The reader should remember that
These problems were presented to the subjects collectively and, therefore, in writing.
Although such subjects had the sufficient reading level to perform the task and
the time factor was not taken into account, we cannot deny that reading and writing
through the Braille system has disadvantages when compared to visual reading.
As exhaustively analyzed in chapter 6 of this same book, tactile reading
it is much slower and more laborious than the visual, which can undoubtedly affect the
results of the tests. Regarding the causal reasoning test related to the
cure of the disease, it is important to remember that blind adolescents and adults
they tended to close the task more prematurely than the seers. Although probably
new jobs are needed to confirm this trend, it is possible to think that
is also attributable, to some extent, to tactile exploration. Although the material of the
the test would be easily explorable by touch and would not present problems
figures, the
made of exploring the dishes with information about treatments and results of
slow and successive, can cause greater fatigue and, consequently, to try
to finish the task prematurely.
Despite the difficulties involved in using the haptic system, everything seems
to indicate that, coinciding with the onset of adolescence, the blind develop
reasoning skills very similar to those of sighted individuals, surpassing them
difficulties they encountered in solving certain tasks during the school period. Like
We have stated in previous publications, the evolutionary leap that characterizes development.
The production of the blind occurs between the ages of thirteen and fourteen (Ochaíta and Rosa, 1988; Pozo)
and col., 1985; Rosa and Ochaíta, 1988). It is approximately at this age when access
Formal or abstract thinking allows blind individuals to overcome many problems.
figurative derivatives of the lack of vision. However, as has been emphasized
manifesto in the research conducted with psychics, the development/learning does not
it stops at that age (see, for example, Carretero, 1985, or Carretero and García Madruga,
1984). Consequently, when complex reasoning tasks are used - such as the
of the healing of the disease or that of the balance, and are carefully analyzed the
strategies used by the subjects are observed, just as happens with the seers,
clear progress in the development of blind individuals at later ages. More
specifically, the results obtained by our work team (Ochaíta et al,
1988), allow us to conclude the existence of significant progress in reasoning
of the blind people aged 17 and 18.
To conclude, let's reconsider the gap between the figurative and verbal aspects.
that characterize the development and learning of the visually impaired. The data with which
we talk about the acquisition of formal thinking allows us to assert
that the blind can solve figurative and spatial problems of logic
concrete to the same ages as those involved in formal logic. Without a doubt, everything
seems to indicate that the lack of vision leads the blind to evolve differently than
the seers, although ultimately the intellectual capabilities of both may
to consider themselves similar. The explanation of the development of the blind raises serious
problems for theories that, like those of Piaget and the Geneva school, aim to
demonstrate the existence of universal stages in the development of all beings
humans and place little importance on the role of language in cognitive development.
As we will analyze in depth in the last chapter of this book, the
The characteristics of the development of the blind can be better explained through theories.
which, like the Vygotskian perspective, place great importance on language in the development of the
higher psychological processes.
Chapter 5
MOBILITY AND SPATIAL KNOWLEDGE IN THE ABSENCE OF VISION

JUAN ANTONIO HUERTAS; ESPERANZA OCHAÍTA and MARÍA ANGELES

ESPINOSA

The reading of the previous chapters of this book will undoubtedly have led the reader to
to think that one of the most important problems for blind and visually impaired people
visual is the knowledge of the space that surrounds them as well as movement and the
orientation in that space. Indeed, in the previous pages we have gone
indicating that when vision is lacking, it becomes much more difficult for human beings
collect, process, store and retrieve precisely that environmental information
which is of a figurative or spatial type. Thus, in chapter 3, we indicated that the
characteristics of the sensory modalities that the blind person must use to substitute for
the vision makes it more difficult and expensive to collect information about the
spatial characteristics of the environment. In the following chapter, dedicated to development
psychological, we put of
I manifest how in early childhood, it is precisely all the aspects
related to the knowledge of objects and the space that contains them
they posed greater problems for blind children. We also pointed out that, in the
subsequent development and up to adolescence, blind children show delays
important regarding the psychics in those aspects of their cognitive development more
related
with figurative and spatial problems. Precisely in this chapter we aim to
address all those aspects related to the ability of the blind to
to know and represent the space around them, as well as to move and orient themselves in
such space.
The importance that human beings attribute to vision for mobility and
spatial knowledge has led many authors to wonder if it is possible that the
blind people -especially those who have never seen- are able to come to know with the
the same effectiveness of a psychic the space that surrounds them. Philosophers such as
Molineux, Locke, Berkeley, or Diderot were greatly concerned with this topic.
Currently, almost at the borders of the 21st century, the different psychological magazines
they continue to publish numerous articles on various topics related to the
orientation, mobility, and spatial representation in blind individuals.
As we will see throughout this chapter, despite the antiquity of the subject and the great
importance it has for psychological theory and for educational practice of the
the visually impaired, even today we lack definitive conclusions on aspects such
important as the relationships between spatial behavior and representation, the different
variables that modulate the abilities of blind people to perceive the environment,
the most suitable methods to objectify spatial representations of the
blind people or the orientation and mobility techniques that are most effective for them
blind and visually impaired.
Furthermore, we currently lack studies that analyze, from a perspective
holistic or globalizing, the way the lack or severe deficiency of the system
visual influences the transactions that occur between the individual and the environment that
surrounds it. More specifically, we refer to research that takes into account the
the fact that, since blindness leads the individual to develop alternative pathways to
relating to space, it does not have the same meaning for a blind person as for a
seer. This does not mean, of course, that a blind person cannot reach
to know or to interpret a certain environment, that is not able to acquire
knowledge about him. What we mean to say is that blindness leads individuals
to relate to space in a qualitatively different way than that of sighted people.
Before developing the content of the chapter and, consequently, studying the
peculiarities of mobility and spatial knowledge in the blind, we believe
it is necessary to clarify what is normally understood by knowledge and
spatial representation in literature on the topic.
The authors who are positioned in the transactional and multidisciplinary perspective that encompasses the
the study of behavior and spatial knowledge often agrees that
when we talk about 'spatial knowledge' we refer to a series of
complex exchanges that involve cognitive and emotional transactions between
the subject and the environment that surrounds them (Gauvain and Rogoff, 1989), which pose a
cognitive and symbolic interaction between the subject and the physical environment in which
it is immersed. In the words of Moore and Golledge, environmental cognition is "the
knowledge, images, information, impressions, and beliefs that individuals and
groups have regarding the elemental, structural, functional, and symbolic aspects
of physical, real or imaginary, social, cultural, economic, and
politicians" (Moore and Golledge, 1976, p.3). Traditionally, publications about the
they usually distinguish between two types of environmental knowledge: the one that refers to
to the judgments about space on one hand, and the one that refers to representation on the other
another. As has been said, from a transactional perspective, this differentiation
between judgments and representations is quite artificial. Judgments and representations
are difficult to separate from the exchanges between the individual and his
environment. Nevertheless, it is advisable for educational purposes to take into account what the
classic authors in the field of environmental psychology define as judgments and as
representations.
When talking about judgments about space, it refers to reactions and
attitudes that different people have towards the elements of the environment. Thus, they
they include aspects such as the effects that environmental noise has on the
human behavior, the preference that an individual may have over
certain landscapes or urban designs, etc.. In the field of psychology of the
blindness, the works of Passini's group (1986 and 1988) on the preferences that
The visually impaired have closed spaces in front of open ones, which constitutes a good
example of what we have called 'judgments about space'.
When the term representation or cognitive map is used, it refers to the
processes involved in the collection, symbolization, memorization, and evocation of the
data that constitute a certain environment. Consequently, reference is made to the
cognitive processes that are triggered when a person, once they have
gathered information about a specific space, such as their own city, organizes and
store that information for later recall. Following this classic distinction,
This chapter is primarily concerned with the study of spatial representation.
It is advisable, however, that we first make some considerations about the
psychological meaning of the concept of spatial representation.
Authors such as Downs and Stea (1983) have used the terminology of "map"
cognitive" taken from Tolman's initial work (1948), which suggests, in some way,
way to make an analogy between cartographic maps and representations
spatial of individuals. For our part, although we recognize how graphic that
It can be said to talk about 'cognitive maps', we prefer to use the term
representation. Precisely because we do not want to assume that the
representations that individuals -especially those who lack vision- develop
about a certain environment must necessarily take the form of a map that
suppose an analogy between the represented space and the real one.
We also think that the study of representation cannot be reduced to a
discussion about the way we have stored information about our
environmental transactions. The ultimate goal of the study of environmental cognition does not
must exclusively try to elucidate whether our spatial memories are
stored in an analog form, in something like a collection of maps or images,
or rather they follow a format similar to a logical series of orders
computational.
Previously we defined the concept of spatial representation as a process and, if
this is the case, it only makes sense to study representation in its formation and development, in
its own activity, without trying to fossilize it. A psychic process, in our opinion, is
something always changing and that has its reality when it is in operation. Not
then it fits with this stance to seek a definitive product, the fixed representation
that a
The individual has a permanent photographic map of an environment. The concept
representation rather means a certain way of understanding and organizing the
knowledge about space, which will vary as any of
the multiple physical, emotional, symbolic, etc. aspects that make up said
environment.
In order to facilitate the study and analysis of spatial representation, we can
to talk, although somewhat artificially, about two different types of information contained
in these representations. The numerous authors who have studied this topic (the
The reader can consult the article by Carreiras, 1986), distinguishing between the information.
attributive and locational. We call attributive information to those aspects
contents in the representations that refer to the meaning they have
places for the individual as well as the value and the function attributed to them. On the other hand the
locational information contains the parameters related to location or
situation of those places. Specifically, it contains information both about the distances
that separate the different elements that constitute space, such as on the
directions or guidance that have such elements.
Each individual has their peculiar way of organizing their environmental representations.
Therefore, there are no standard patterns that determine how they should be.
representations of a specific space. Moreover, it is important to take into account that the
the representation that an individual has of a place changes as it acquires
more experience with that place. This means that the new knowledge that
continuously acquired through practice, compel the person to restructure their
own
representation or 'spatial scheme'. However, we cannot say that the
environmental representations are fragile and momentary, on the contrary,
precisely those representations or 'spatial schemes' are quite resistant to
forgetting, as an organizing guideline that is of a whole set of contents in a
determined space.
Finally, we call mobility the actual spatial behavior that a certain
the individual develops in a specific space. It is a complex behavior in which
Processes involved are not only perceptual and motor but also representational.
Thus, having a representation of a certain physical environment facilitates
enormously to the individual, especially when they are blind, mobility and orientation in
said environment. and this is primarily due to the fact that in that representation it
includes the memory of the location information that is most important for
movement and orientation in a large space: size, direction and the
distance of the significant elements that make up that space.
This chapter deals with examining the most important aspects of mobility and
spatial representation in blind and visually impaired people. It begins with a
review of the sensory systems that are involved in the collection of the
spatial information when vision is lacking or severely impaired. A
the following analyzes the capabilities of the visually impaired to move and orient themselves by
the environment, the various procedures or techniques used by experts to improve
that mobility, as well as the most commonly used 'assistance'. Later on,
they review the form and content of the spatial representations in the
visually impaired adults. The fourth section is dedicated to the study of development of
spatial knowledge in blind children and adolescents. This is followed by an analysis of
certain attention to the different factors that affect the capabilities of
spatial representation of the visually impaired. Section seven studies the different
procedures that can be used to objectify or 'externalize' the
spatial representations of blind and visually impaired individuals. And, finally, it is analyzed
the contributions of research on knowledge and spatial representation to
the teaching of geography to blind and visually impaired students.

1. Perceptual factors involved in movement and knowledge

spatial

When an individual moves through a certain place, they are gathering a multitude of
environmental information with the different sensory systems available.
Precisely these perceptual data, if they are sufficiently complete and specific,
they are the ones that allow that individual to move through space. Additionally, that
perceptive information, as we train ourselves to know those reference points of
environment that is necessary for us not to get lost, enables the elaboration of a
I remember a more or less accurate representation of that environment. This
representation or memory is what will make it possible for us to traverse that in the future.
Place or similar ones. It is, then, as important the role that information plays.
perception in mobility and spatial orientation, when some channel is missing
for the collection of such information -especially the visual-, both moving and
Remembering the space poses significant difficulties. We do not want to repeat it.
ideas and data that we already discussed extensively in chapter 3, we just think that
it may be helpful to begin this chapter by reminding the reader, if only briefly,
the possibilities that the different sensory modalities available to the being have
human to perceive spatial information. But before that, we believe it is necessary
refer to the concept of 'perceptual anticipation' which is of great importance in
the field of environmental perception.
When we talk about perceptual anticipation, we refer to a property that they have
some sensory modalities, which allow the individual to know in advance
(before having direct contact with the objects), the arrangement, size, and type
of objects that are found in a certain space. Thus, perceptual anticipation
makes it possible for a walker to foresee the obstacles that are found on a route and
that detects reference points at a certain distance, while also helping to
correct or guide the course. Vision is the perceptual modality that requires the most anticipation.
provides and which, consequently, allows the individual to engage in other activities
while walking, such as talking to a friend, reflecting on certain
events, listening to music, etc.. Of course, blind people do not have
a perceptive anticipation capacity as broad and complete as that of seers.
When vision is lacking, the individual has to resort to sensory modalities that
they gather information slowly and fragmentarily and pose greater challenges
difficulties in anticipating information. Moreover - as we will analyze throughout
this chapter - the lack of this sensory system makes it necessary for the blind individual
use his memory resources, representation more frequently than the seer
spatial, decision-making and other cognitive skills. All of this can,
at times, to occupy the functional capacity of your cognitive system, so the
The blind person must dedicate all their attentional resources to the task of walking.
The maximum capacity to perceptively anticipate the information that one may have
the distance this person travels while walking is 76 meters.
walks normally in one minute. In contrast, a blind person walking with assistance
from a cane, only manages to anticipate one meter, or one and a half meters, his information by
Every sweep I make with that cane. Thus, to approach the temporal average of
perceptive anticipation of a seer, the blind person should perform a sweep every 0.8
seconds, which, of course, is totally impossible. But also, even in the
hypothetical case that they were able to do the sweeps so quickly, they could not
to simultaneously perceive the entire perceptual field - those almost eighty meters - but instead
they would do it in a fragmented way, having to relate mentally and in a
continue that series of sweeps.
Let's briefly outline the functional possibilities of each.
sensory system when interacting spatially with an environment. Throughout
History has come to consider vision as the spatial perceptual system.
excellence. Currently, we still uphold this statement as the vision -in
contrasting with other sensory systems - allows to perceive simultaneously a
broad sector of the environment. Moreover, for visual perception to exist, it is not necessary to have a
physical contact with the stimulus, so, as has already been said, the capacity of
the perceptual anticipation of vision is very great. A seer, in conditions
normal people can perceive an object, such as a tree, that is far away
meters away, allowing him plenty of time not to collide with it.
In order not to excessively prolong the presentation of the possibilities that vision has to
spatial perception, it will be enough to point out that this sensory system allows us
easily know the shape, distance, and position of the entire set of stimuli
encompassing our visual field. Consequently, visual perception goes
to allow the individual to organize the space quickly, globally, and stably.
It is affirmed about hearing, on the other hand, that it is a sense equipped for analysis of
temporal patterns, to understand the sequence and duration of a stimulus
environmental. Like vision, it does not require physical contact with the stimulus either, so
that provides sufficient perceptual anticipation, although less than that of the
vision. The possibilities of perceptual anticipation that the auditory system has are seen
limited in fact because there are few useful environmental stimuli for mobility
and the spatial knowledge that can be perceived acoustically. With this
sensory modality makes it possible to identify a whole set of sound elements,
although certain intentional learning is needed for that. However, listening
it only allows obtaining information about the shape and size of the stimuli
environmental. In addition, the ability of humans to estimate distances and
directions with this sensory modality is limited and depends, to a great extent, on the
localization of the sound source. Thus, the research conducted in 1989 by Guth,
Hill and Rieser have shown that the blind locate more easily the
direction from which a sound comes, when the sound source is located in front of
subject that when it is behind. Finally, it is important to highlight the limited capacity that
it has audition for perception or selective discrimination, since for the ear
It is not easy for a human to listen to some sounds while excluding others that occur in the
same amplitude and acoustic intensity. In addition, the auditory modality is more vulnerable
that the visual to the interference of irrelevant stimuli, for example, a good guide
acoustics, like the sound of water from a fountain, can easily be masked
through moderately dense traffic.
Although the tactile, proprioceptive, and kinesthetic senses have receptors and pathways.
Different nervous systems can be said to operate together in perception.
spatial. The haptic sensory modality depends, as has been extensively seen in the
chapter 3, about receptors that are excited by mechanical stimulation of the skin and
for the kinesthetic or movement repercussions that occur when entering this in
contact with objects. For its part, proprioception generally depends on the
internal transduction of kinesthetic and balance signals. These modalities
sensory provide information about shapes, sizes, surfaces, position
relative to objects, as well as the movement of these. Perhaps the most information
important that these senses provide to the visually impaired when moving, be it the
relating to the texture, composition, and outline of the surfaces they walk on. But,
In order for perception to exist with these sensory modalities, it must necessarily be
physical contact between the stimulus and the sensory receptor, which implies that the
available perceptual field, perceptual anticipation, is considerably
reduced. Furthermore, when objects are large, perception and recognition of
the same must be carried out in a fragmented manner. In short, with tact and the
proprioception is necessary to perform serial and successive perceptions of the elements
environmental, which can only subsequently be integrated and organized in a way
joint. However, not everything is limitations in the perceptual abilities of these
sensory systems. Both the effort and the slowness with which the subject is obliged
to take in the information, makes them useful for making certain selective perceptions of the
reality, in which they are often more precise than vision. Many details of objects that
they go unnoticed with the vision, they achieve
with touch to stand out and, in some way, to remain in memory in a way
more permanent. Let's put, for example, how we have come to know the textures of
the objects. Despite this, most of the authors interested in this topic, among
those who should be highlighted are Hermerlin and Qconnor (1982), who maintain the hypothesis that
haptic perception only allows individuals to partially organize space,
originating representations of a subjective or egocentric nature.
Sometimes, perhaps more often than we think, we use our sense of smell to
distinguish and know certain elements of space. Thus, we find or recognize a
establishment, like a bakery, by the smell it gives off. In this way,
when we associate a particular smell with an environmental element, the memory seems to be
quite enduring. Despite this, the scarce number of stimuli that can be
to perceive olfactorily, the limited scope of that perception, as well as the little
precision obtained in the localization of objects and in the estimation of the
distances make the importance of smell in spatial perception very
reduced.

2. Movement and orientation in the environment

2.1. Mobility in the absence of vision

Having good mobility, being able to move around an environment effectively
autonomous and secure, it is something very important for anyone. It is claimed that a
The walker moves properly when they are able to maintain orientation in each
moment of the march, as well as knowing what elements shape the environment by
where it moves and where those elements are. Furthermore, it must be able to extrapolate
the sequence and the direction that those elements take while moving. From this it
deduce that mobility requires the functioning of very different types of processes
perceptual, motor, associative, mnestic, and representational, which manifest in
a set of behaviors of great complexity and difficult study. Thus, the implementation of
the march of the set of processes that mobility implies is particularly
complicated for blind people, as they have to compensate with other sensory systems
the important functions that vision performs, which as we have just seen is the sense
the quintessential tele-receptor.
When a person moves through an environment and -as in the case of the blind- the
perceptual information received is not sufficient, it must resort to certain
knowledge that is stored in their memory, to their schemas or
spatial representations. Furthermore, for a sighted person, and much more for a
blind, moving through a space implies processes of planning and decision-making,
processes that logically involve the use of inductive reasoning strategies and
deductive. Ultimately, there are several cognitive processes that come into play
functioning in ambulation and these become complicated when it comes to walking in
a complex space.
In this regard, Hill and Ponder (1976) propose that there are five cognitive processes.
most relevant involved in mobility and orientation. The first process that is
It is the perception, the collection of data from the environment by the different systems.
sensory. Next, an analysis of the perceptual data is carried out, which
they are organized into categories according to their consistency, familiarity, intensity, etc... The third
the process consists of selecting relevant data from memory for the
current requirements of the displacement task. Next, the fourth process
it involves the development of a plan to determine the sequence of the actions that are there
what to do in the space to be traveled. Finally, the final process involves execution and
the evaluation of the decisions that have been made. The duration of these processes, so
how the greater or lesser ease with which they are carried out depends both on the skills
of the individual as well as the characteristics of the journey that must be taken.
Authors such as Foulke (1983 and 1984) have delved into the third of the
previously mentioned processes, the mnemonic, in order to try to explain how a subject
accesses the knowledge he already has about a certain space. Thus, Foulke
uses the term 'cognitive anticipation' to refer to that process, making a
analogy with that of perceptual anticipation. He then calls it 'cognitive anticipation' to
process that allows the walker to cognitively anticipate perception of
certain stimuli from the environment, using the memory it has of that environment and
elaborating, in some cases, certain inferences of similarity with familiar spaces and
similar. Of course, the processes of cognitive and perceptual anticipation are
intimately related: the more feasible it is for the subject to use information
perceptual will resort less to cognitive, since obtaining this is more costly. For
that's what sighted people do when they have to navigate spaces that are not very large
not very complex, they hardly have to resort to cognitive inferences. However, the
problems of perceptual anticipation resulting from lack of vision cause
blind people have to regularly engage in cognitive anticipation processes.
For this cognitive update to be effective during a displacement, the
a traveler must know or sense at every moment the position they occupy in the
space, and also have some information about certain elements or "landmarks" that may be
serve as a reference to guide their march. As has already been said, the memory that the
the individual possesses from others in similar ways allows them, often, to extrapolate
information when traveling on a new road. This means that, thanks to
regularities are produced in the structure and content of different spaces, thanks to
that certain spatial stereotypes exist, generalizations can be made,
inferences and predictions from the spatial representations that a subject remembers
to a certain unknown or complex space in which one has to move in a
determined moment.
For Foulke (a.c.), cognitive anticipation also serves other important functions.
for mobility and orientation. Thus, it allows the individual to correct and update the
representations or knowledge that one acquires from a certain environment,
since the comparison of the current data with the remembered ones leads him to detect
errors or relationships that do not correspond to the scheme of a route or a space
determined. We will revisit this important topic of cognitive anticipation in the
section 3.5, when studying "the spatial scheme".
Precisely because of the problems that exist for moving in space when there is a lack of the
vision, most blind people have learned, at certain moments in their lives,
various techniques or mobility strategies, despite which many of them do not
they ensure that their movement through the environment is completely adequate, that is,
to be as independent, secure, comfortable, and socially appropriate as that of the
clairvoyants. Often, the problems faced by the blind stem from the route that
they have to do does not provide them with sufficient perceptual information and consequently
they cannot perform the appropriate coding of that information. Other times, the
deficiencies of blind people can simply arise because they lack
experience in mobility -perhaps because they do not walk alone enough - and therefore,
also of the schemes and suitable strategies that allow them to supplement
cognitively the data that cannot be received from vision (cognitive anticipation). Without
doubt, on some occasions, these problems may also be due to the absence of
specific training suitable in orientation and mobility techniques.
according to Foulke (1985), success in a movement depends on the amount,
relevance, adjustment, and specificity of the spatial information acquired and remembered.
As has been said, blind people have difficulties acquiring and encoding.
sufficient, relevant, adjusted, and specific spatial information.
The degree of suitability of a displacement is mainly determined by three
factors: the energy expenditure that it means, the physical conditions of the walker and the
effectiveness of mobility. As we will see in section 3.3, the problems of
mobility that necessarily occurs when vision is lacking or severely impaired
damaged, they have led numerous authors to study various practical aspects
related to the mobility of the blind and visually impaired.
There exists in the literature a certain number of descriptive studies that have attempted
indicate what type of spaces are preferred by blind and visually impaired people
visuals. Interested readers can refer, for example, to the works of the group of
Passini's research (1986, 1988). In general terms, these studies have highlighted
of
I manifest that the majority of adult blind people can move around in a way
autonomous and even recreate themselves while walking through an environment where there are
sufficient informative keys, both auditory and kinesthetic, that are lasting.
through time. However, in wide spaces, in which the points of
acoustic references are difficult to perceive, the autonomous movements of the
blind people are more difficult. With this we mean that the difficulty that a
Visually impaired individuals have to navigate in a space of this type, it is not so much due to the
amplitude, extension or architectural structure that has otherwise, rather, to the scarce
stable auditory, tactile, and kinesthetic information that such space provides.
Logically, this difficulty is less for the visually impaired than for the blind.
but only when they know how to properly use their visual scraps. According to
the data from Passini, Dupre and Langois (1986), 50% of visually impaired individuals visit
and often use public sites, despite the fact that the rest is often visual.
what they possess seems rather to hinder than to help in the movement since, by
For example, it can confuse the shadows of objects with real objects, etc.
However, the percentage of totally blind individuals who used those public places
The autonomous form was only 10%. From this it is deduced that it is absolutely
It is essential that individuals with severe visual impairments receive training courses.
suitable ones that allow them to effectively use the scraps visuals for their
displacements. As we will analyze in section 2.3, when specifying what
training classes must be received by people with severe visual impairments, it is
it is equally essential to determine the type and amount of residual vision that
belong. The work recently done by Long, Rieser, and Hill (1990) seems
indicate that the amplitude of the visual field and sensitivity to contrasts are aspects
more related to mobility than others such as, for example, visual acuity.
In any case, the impact of urban planning aspects cannot be underestimated.
situational and even climatic factors have for the orientation and mobility of the
blind people. The statements made in the previous paragraph referred to,
basically, to the buildings and enclosed spaces for public use. That's why we think that
they are not in contradiction with the fact, also demonstrated, that in spaces
open, are precisely those that are most crowded and have a larger number of
"mojones" those that allow the blind to move and orient themselves better. Precisely because
these provide them with a greater number of directional and distance keys than the
wide, peaceful, and little-trafficked environments. Certain climatic aspects are also
important as they affect the possibilities that the visually impaired person has to
collect information from the environment. Thus, for example, snow and rain decrease the
possibilities to discern the different reference points, while the wind
it makes it difficult for blind people to discriminate between auditory cues. As for the
architectural and urban variables it should be noted that there are certain barriers that
they confuse the visually impaired and thus hinder their mobility. It is about,
example of stairs without railings, subway entrances, construction works and scaffolding in
the streets, the doors half-open, etc.
Lastly, we cannot forget that blind people, when moving around, also
to have to use a greater amount of information and memories about the environment than
the seers also have to make more complex decisions. As you can imagine
the reader, many of those decisions (such as crossing a street with high
traffic density) pose risks, even physical ones. These risks and the
negative experiences that many blind people have undoubtedly had in their
urban displacements explain the anxiety and stress that they can cause.
the act of moving through the streets of a city. Thus, we can affirm with Foulke
(1984), for blind people, mobility is a complex activity,
intended, planned, and directed towards a goal that is absolutely
necessary to carry out with a high cost of cognitive resources. As a consequence, the
blind people do not usually walk the streets of the city -like the sighted do- with
only recreational fines.

Let us now briefly review the social and personality aspects that are
related to the mobility of blind people. Probably, the sighted
we find the task of moving and orienting ourselves in space so simple that we are not
aware of the scope and importance it has for all aspects of life
everyday, having adequate orientation and mobility. Specifically, for the
people with severe visual impairments, the ability to move freely
autonomous and secure affects the characteristics of her personality and is, without a doubt,
intimately related to the possibility of having social contacts.
Thus, for example, Hill and Ponder noted in 1976 that having mobility
independent is directly related to the development of feelings of
self-esteem and self-confidence of the visually impaired. On the contrary, the
individuals who have trouble moving independently remain
harmed in their psychosocial relationships, they have difficulties in their relationships
personal and worse image before others (Welsh and Blash, 1980). Of course, these
authors have limited themselves to confirming the existence of correlations between certain traits of
personality and the ability to move appropriately, without being able to specify
the direction of that causality. It can only be stated that for blind people the
The ability to move independently is closely related to the adjustment.
personal, it is not the mobility capabilities that produce that type of adjustment.
It is quite evident, moreover, that mobility facilitates social interaction among the
blind people. Those who are not able to move independently and
autonomous have few opportunities for social gatherings. Many of the
daily life activities can only be carried out if the individual has some
possibility to move efficiently. Activities such as the following serve as an example
how to go shopping, attend places dedicated to leisure and entertainment, get around
daily to work, etc...
Lastly, let us remember, even if very briefly, some other aspects in which
positively influences mobility. Of course, every move implies a
physical exercise that involves the activation of certain motor skills. The
the need for a minimum amount of exercise is sufficiently demonstrated in our days and
it is as essential for blind people as it is for sighted people. On the other hand
part, we all know that we live in a dynamic and changing society, in which the
the ability to move autonomously allows the blind individual to save
human and economic resources. In summary, we can say that for an individual
blind person can integrate socially and professionally, it is necessary that they possess certain
abilities to move through the environment autonomously.

2.2. Components of spatial orientation

Although orientation and mobility are two closely related aspects, and although
the reader has come across the term 'orientation' in the previous section, we have believed
It is necessary to dedicate some pages to specify what we understand by orientation.
spatial. Without a doubt, for a person to be able to walk without getting lost in an environment
complex, like a city, it is not enough just to know how to move around, it must be
also capable of orienting itself, of knowing its position at every moment of
displacement. In the field of blindness psychology, a good amount has been done
number of investigations on the subject. Thus, authors such as Rieser, Guth, and Hill
(1982) Y Hill (1986)
they consider that the orientation process involves three main components: a) the
knowledge of the positions of the reference points, b) the update
perceptive and c) the use of certain conceptual systems related to management of the
space. The following three components are analyzed in some detail.
First of all, every traveler must know the layout of the route they must take.
follow at least the marks or milestones that allow you to know if you are still on the path
suitable. In addition, you must keep in mind the relative positions taken by the
different objects and places while walking. In relation to this, the data
experiments show that the accuracy in orientation is inversely
proportional to the number of curves or changes of direction that exist in a route
(Linderberg and Garling, 1981) and the length of the path to be traveled (Thompson, 1963).
The following section will analyze in some detail the techniques that are
they are used to teach blind people to navigate a specific space.
b) In order to orient themselves, secondly, the individual must be able to update in
every moment of the march, their own position in relation to the elements
significant aspects of the environment, of maintaining the relationship between their body and the so-called
"myones." In the case of sighted people, this process of perceptual updating
does not necessarily imply the activation of complex cognitive processes.
Normally, a seer can automatically update the relative position
that it is taking regarding the environment, just by perceptively checking the position
what the environmental elements have at every moment regarding their own body.
This ability to realize how objects rotate with respect to a walker
an environment is also determined by attributive information, that is, by the
meaning that the different environmental stimuli have for that walker
(Carreiras, 1986). Thus, he will pay more attention to the stimuli that have for him a
more pronounced significance and will almost forget the position of those others to whom
Don't give it any importance.
Study how the process of perceptual updating occurs in the absence of
vision is of great importance. Rieser, Guth, and Hill conducted research in 1982.
with the main objective of understanding the existing relationships between visual experience
of individuals and their ability to carry out perceptual updates of the
elements of the environment, in a displacement. The subjects (congenital blind, late and
psychics) after having learned the arrangement of the elements in a room
through a series of training sessions, they had to move through it,
pointing out the position of those elements from different points located along the
journey. The blind from birth made a greater number of mistakes than the
two other groups of subjects when estimating the direction of the elements. In a
continuation of the work done in 1986, Rieser, Guth, and Hill attributed the lack of
ability of the blind from birth to carry out perceptual updates, to the
difficulty that these subjects face in updating their own situation regarding the
environmental elements. People who have never seen, when having to do for
to orient oneself, cognitive type elaborations - and not only perceptual updates such as
the seers need more time and more cognitive resources to know the
directional relationships that are established between the elements of the environment in each
moment of the journey, which increases the likelihood of making mistakes.
More recently, Hollins and Kelley (1988) conducted an experimental work with the
ultimate goal of investigating the generalizability of the data from Rieser and collaborators.
Chapter 5
MOBILITY AND SPATIAL KNOWLEDGE IN THE ABSENCE OF VISION
they were in charge of rehabilitating late blind people, teaching them to collect and use
information about the environment through senses other than vision. As
more and more programs were developed, they have been completed and diversified
and, moreover, they have adapted to work with children, including aspects related to
the development of spatial knowledge. Programs have also been designed for
people with visual remnants, putting all their interest into taking advantage of the
functional vision and the aids that can be used by visually impaired individuals.
In recent years, much more specific programs are being developed, such as
they are those who intend to meet the mobility needs of children of ages
very early, of blind people who have associated deficiencies or of the
blind elderly population.
Next, we will describe in more detail some programs of
Instruction in orientation and mobility more prototypical. They will be grouped into two
categories, based on the nature of the environment in which it takes place
such instruction: those that are developed in an artificially created environment and the
that take place in a real environment.
Klee and Klee developed, in 1985, a training program in an environment
artificial. The objective of this program was to improve the basic skills of the blind
for the displacement, including two important auditory skills in them: the
discrimination and sound localization. The program also aimed to enhance
degree of concentration, memorization, retention, and environmental knowledge of the
subjects. In the first training sessions, no special aids were used
for the
mobility, but the authors recommend the use of the cane in a second phase of
program to consolidate the instructed skills.
Each part of the program consisted of 20 sessions lasting between 60 and 90.
minutes. The work was carried out in a closed room with a hard floor and without
carpets (since they absorb the echo produced by certain activities). Before
perform the exercises corresponding to the first part of the program, the students
they learned, individually, the basic techniques for protecting the upper part and
lower part of the body. They were also trained to learn how to walk in line
straight, without any kind of help, while maintaining a correct posture.
The first part of the program consisted of seven different exercises arranged
following an order of increasing difficulty. In exercise I, two rows were placed of
chairs, one facing another, at an approximate distance of about 2-3 meters. In one row there
the students were seated, and on the other side stood the instructor facing them.
I asked the students to locate the chair behind which the ... was placed.
instructor.
No one should respond until explicitly asked, which, for the
authors, would increase the attention and interest of the students. When the instructor
designated a student, he had to get up and go to the chair behind which
the instructor was placed and, subsequently, return to the site from which he had departed.
This task aimed for the student to maintain orientation, in addition to remembering.
approximately its starting point. The exercise can be repeated several times,
increasing the distance between the rows of chairs, until reaching
approximately 5-6 meters. If any student had difficulties locating the
correct sitting position of the chair, the instructor had to provide certain verbal aids,
to ensure that the student did not experience a total feeling of failure.
Exercises II and III were basically the same, but in this case, the chairs were placed.
forming irregular angles (exercise II) or large tables or other objects were placed
between the two rows of chairs (exercise III). In this way, it was increasing the
difficulty of the exercises. since the path that the students had to follow was
It deviated more and more from the straight line.
In exercise IV, the instructor interrupted the student on their way to the chair.
destination, distracting him with a conversation of no importance. Exercises V, VI, and VII,
They were trying to improve the student's skills to discriminate sounds. In a
Initially, the subjects had to discriminate between the sounds produced by different
objects, but gradually the task became more difficult because the sounds were produced
each time with more similar objects (exercise V). In exercises VI and VII in addition to
to recognize the object that was producing the sound, the blind person had to locate its source
(exercise VI), go to pick it up and deliver it to the instructor in exercise VII.
Once these exercises were completed, in the second part of the program, the participants were instructed to
students in the use of the cane in its two versions (short and long). When they had
having acquired sufficient effectiveness in the use of both canes, the series was repeated
exercises taught in the first part of the program, but in this second part the
The localization of objects was done using the cane.
In our opinion, this type of program, of which we have just mentioned only a few.
example, it may have generalization problems in natural environments. So
supposedly, the complexity that moving around entails for a blind person is not comparable
a room in which a series of obstacles have been placed (the arrangement of which is
it has been previously shown), with the daily task of commuting from home to
work, to the study center, etc. Natural spaces have dimensions and
characteristics, both physical and structural, much more irregular and complex than
the artificial spaces. Therefore, the strategies for collecting and using information in
Some spaces must necessarily be different. For example, when a
a blind or visually impaired person moves through a natural environment, using as
keys for gathering information a complex and very large data conglomerate
variables such as the textures, the slope of the ground, the noise produced by the cane when
to collide with certain types of objects (in the case of moving with the help of the same),
the noise of the environment, the echoes, etc. Keys that, without a doubt, do not appear the same
manner when instruction occurs in artificially created environments.
On the other hand, we do not have precise data regarding the persistence of the
skills acquired through these training programs developed in
such concrete environments, when the learning period ends. Said in another way
We do not know to what extent only temporary skills are acquired that can...
disappear when they stop being practiced, or if on the contrary, they are permanent.
For all this, we believe that programs to enhance the skills involved in
orientation and mobility in artificial environments should be examined
carefully in light of its validity to allow subjects to move through a
real and complex environment, autonomously and securely. Now, we do not want to
you are
criticize the impression given to the reader that orientation and mobility programs that
those trained in artificial environments have no advantage at all. On the contrary, they are
important for instructing the visually impaired in basic skills for orientation and
mobility such as knowing how to orient oneself towards sound sources, discriminating between
different sounds, maintain a correct posture, know how to walk in a straight line, detect
obstacles with or without a cane, etc... However, we believe that when these skills
basics have been learned in a safe and controlled context such as an environment
artificial, they should be put into operation and complemented with developed programs
in natural environments.
Most blind and visually impaired people have received, in certain
stages of his life, instructional programs in orientation and mobility that
They develop in natural environments. It is these programs that allow for the...
blind people moving around a big city, using public transport and,
consequence, to integrate into working and social life. Despite this, we have not
found in the review of the literature on the subject, publications that detail the
conditions under which these programs must be developed. This is likely due to
the difficulty involved in adapting a specific program to the different characteristics
(structural, perceptual, complexity, size, etc.) that necessarily have the
natural environments. Similarly, it can be difficult and even inappropriate to talk about
general programs when they must be implemented with populations as
heterogeneous as that of the visually impaired.
In any case, it is clear that the orientation and mobility specialists in charge
from the instruction of the visually impaired, they use some general guidelines to
promote the learning of routes in natural and complex environments. Such guidelines are
based on the enhancement of cognitive processes that Hill and Ponder (1976),
are considered more important for the orientation and mobility of the blind. In
general terms, when specialists have to design the instruction of a
they do the following for a blind or visually impaired person:
First of all, the technician must select those important elements on the route.
that can be perceived through non-visual sensory systems, for what
can serve as milestones or keys. The selection of the elements of the route that
They will be used as keys, it must be done carefully, always choosing those
that can provide more information to the subject and that remain in the environment
more stable (such as the noise produced by cars when
they march in one direction, the sound of a fountain, the smell of a bakery, etc.)
2. Once the keys through which the subject should be guided are chosen, they must be
organized in a structured sequence of actions that allow for their detection and
interpretation. Such a sequence must allow the visually impaired individual to integrate into their memory the
organization of route keys and retrieve that information when needed.
Thirdly, the individual must carry out their journey along the route accordingly.
with the received instruction. Subsequently, both he and the instructor must evaluate the task
carried out. For this, the usefulness of the keys and the
suitability of the acquired spatial organization. The adjustment must also be evaluated.
of the decisions made by the subject.
This type of instructional program for route learning is the most widely used.
for the education of visually impaired individuals. As we have already mentioned, the greatest
part of the people with serious vision problems have received some of these
programs throughout their life. For this, there are guidance instructors and
mobility in the organizations of the blind in most countries.
So that blind people can lead an active life without relying on other people to
their movements need to be instructed in the learning of certain routes. Thus,
they receive teachings to be able to move along those paths that are theirs
essential in their everyday activities, such as the way of moving around
home to work or to the educational center, from work to the place where the special center is located
for the blind, etc.. But it must be taken into account that these concrete learnings can
to generalize: the blind individual - depending on their own characteristics
personal, the amount and quality of the instruction received and the space available
You can use and adapt the knowledge learned to navigate through others.
places. In this sense, they learn to determine what the spatial keys are that
they can be more helpful on a new journey, knowing what questions are most useful to them
appropriate to do in this type of movements, to use the cane correctly,
etc...
There are two fundamental reasons why guidance programs and
mobility that develops in large and complex natural environments often instructs
to the blind from adolescence. On one hand, as the reader will be able to verify
in section 5 of this same chapter, the spatial knowledge skills that
such programs are not usually acquired and mastered properly before
this period of life. On the other hand, it is precisely from adolescence that the
boys need to move independently. However, the instruction
in all aspects related to motor development and mobility of the
blind people, it must start in early childhood in order to prevent problems in
this area that do not necessarily have to be associated with blindness. The data
obtained by authors such as Margot and Palazesi (1986), Hill, Spencer, and Baybbut
(1985), highlight that certain skills acquired in the early
years of life - more specifically, localization of sounds and self-knowledge
Body can serve as a predictive criterion for orientation and mobility in life.
adult. In this sense, it is important to briefly outline the program of
intervention designed by Joffee in 1988 for blind and visually impaired infants.
Based on the analysis of motor development conducted by Fraiberg and Adelson (1974), the
the program is aimed at maximizing motor development and mobility
blind children. It is designed to be carried out at the home of the
child with the total involvement of the parents who, finally and once trained, are
the people responsible for the development of the intervention. Once they have created good
Expectations about the development possibilities of your baby are trained.
so that they interact with him to the fullest in the different situations of domestic life,
using songs and games during bath time, meals, etc., as well as exercises
simple activities to stimulate the child's motor development and knowledge of themselves
body. Likewise, parents receive instructions so that the child can go
progressively getting to know the space of their own home. This is achieved by creating
attractive environments for blind babies, identifying with appropriate stimuli the
different rooms of the house, as well as guiding the child through them, always following
the same route, accompanied by simple verbalizations.
To conclude this section, we find it appropriate to point out the general conditions that
must comply with a good orientation and mobility program. Firstly, before
start the training, the teacher must take into account whether the student has or not
visual remnants and, if any, to what extent they are usable for the
training. That is to say, it is absolutely necessary, prior to any
intervention, a
good assessment of the useful visual rest of the person to be trained. In addition, the application
The program's concrete implementation must begin with the prior assessment of capabilities.
mobility and spatial knowledge of the people to be instructed. In
third place, it must have a detailed analysis of the tasks that are going to
to teach itself, including the timely sequencing of them. Finally, it must
include some procedure to evaluate the results obtained which,
normally, it depends on the characteristics of the program. It is therefore difficult to work,
without prior adaptation, with standard performance evaluation tests in a
program
Most programs conducted in natural environments usually
use the evaluation made by the student or the teacher of the success achieved, for which,
they usually take into account if the subject has been able to follow the route without difficulty and
to reach their destination. However, there are other procedures that allow
greater precision and rigor, although these are normally only used when it is carried to
I completed an experimental evaluation of the program. One of them consists of the
observation of the subject's behavior during the journey, for whose analysis they can
use different criteria such as the number of deviations and losses, number and type of
support requested, frequency of trips, time spent on the journey, etc.. It is
It is important to note that both procedures - observational measures and evaluation
of the professor - they seem to correlate high and positively, as noted by Geruchat and
From L'Aune in 1989.
From our point of view, it would also be very convenient for the instructors of
orientation and mobility evaluate the spatial representations obtained by the
blind and visually impaired subjects once a certain route has been learned:
Precisely, this type of evaluation is of great interest to these subjects for two reasons.
fundamental reasons. On one hand, as we have already mentioned on previous pages, the
people who lack vision, due to the limited perceptual anticipation that they
they provide the remaining sensory systems, depending more heavily on their
cognitive representations or anticipations. Additionally, the use of techniques for
Objectification of spatial representation can help the visually impaired to better structure.
the environment that has been learned. In this sense, it should be attempted that, to the extent that
possible, the visually impaired person can not only represent the learned route in a way
rigid and sequential, but also achieve a representation of type
configurational or global that
allows greater flexibility in your movements. In section 7 of this chapter
The methods that can be used for blind people are detailed.
may externalize or communicate their spatial representations.
Undoubtedly, the effort made by the related organizations is very remarkable.
with the blind to perfect orientation and mobility programs. Without
embargo, one of the most important criticisms that can be made of the programs
current orientation and mobility services are not designed based on a framework
general theory about the relationships between the subject and their environment. From our point
From a viewpoint, it would be necessary that both the design and the subsequent evaluation of such
programs would agree with a transactional model that would reveal
the complex relationships that occur between the subject and the environment and that will be analyzed
the meanings that this generates in visually impaired individuals. Consequently,
the programs we are referring to should also take into account the
most important empirical findings that have arisen in the research
about environmental psychology and, more specifically, about knowledge and representation
spatial. Thus, there would be greater theoretical and empirical support on which to base the
practical decisions that must be made when instructing blind people and
visually impaired. But in the same way that we miss an integration of
the theoretical models within the professional framework, we must criticize the lack of knowledge
that many of the researchers have about how students are normally taught
blind individuals in orientation and mobility. The scientific activity distanced from reality
about which it investigates and theorizes makes as little sense as the practice that does not have in it
tell the theory.
An example of integration between theory and practice is the program of
mobility instruction prepared by Bina in 1986. Starting from the most data
relevant findings obtained from research in the field of knowledge and the
spatial representation, this author believes that children should be instructed in
first years of his/her
schooling, in four basic skills necessary to navigate a space:
understanding of spatial concepts, estimation of distances, interpretation of
cartographic representations, and adjustment of mobility along the route. The instruction
in the different skills is arranged according to the degree of difficulty that
are presented and are carried out through games that take place in environments
natural settings with both blind and sighted children participating. Teaching through
the use of games increases children's motivation to engage in
movements, also promoting cooperative work and social integration of
the visually impaired.
Finally, when designing orientation and mobility programs, it is important
take into account that there are individual factors such as stress, anxiety, the
self-esteem, self-confidence, insecurity, fear, etc., which will be
determinants when a blind or visually impaired subject learns or does not learn to
to move and to
orient oneself within a certain environment. Some experimental works (O'Donnell,
1988; White, Carroll and Martin, 1990), have highlighted that stress is a factor
important when determining the degree and effectiveness with which an individual acquires
skills for mobility. There are some strategies that can be useful for
try to reduce the anxiety caused in some blind and visually impaired people
visuals, such as fostering appropriate empathy between the instructor and the
student, establish a sufficiently long adjustment period for the
the subject
lose your fears, plan the training carefully, provide the
appropriate feedback about progress, ensuring that the subject achieves success
In their first attempts, etc... The teacher must take into account that the problems to which
we refer to aspects that affect the learning process and, as far as possible,
to have
adapt the program to the characteristics of each of your students, so that
they can gradually overcome such problems and acquire the skills that are
they are being taught.

2.4. Assistance for orientation and mobility

As the reader already knows, one of the most serious problems associated with blindness is the
scant perceptual anticipation provided by the alternative sensory systems to
the vision. Therefore, blind and visually impaired people have great difficulties.
to perceive the objects that are in its path before they make contact
with their own body. It is precisely these problems and difficulties that have
brought together people and institutions related to the visually impaired to design different
types of devices that can help them in the difficult task of moving and
orienting oneself in space. One of the oldest aids - and as we will see in
continuation also more effective - is the cane.
The use of the cane as a tool to assist the visually impaired is introduced such
as we know it today in 1940. Its use allows them to detect obstacles within
a radius of approximately one meter or one and a half meters resulting in this,
useful to avoid collisions with other walkers. The very design of this aid allows
that it is used quickly at any sign of obstacle and, consequently
it enables a certain independence in autonomous movements.
Traditionally, it was believed that the blind person should have some prior skills first.
to use the cane, skills that I should acquire while being guided by a seer and/or
through the follow-up of certain guidance techniques. Currently, the opinion
from orientation and mobility specialists is that such skills can
learning to use the cane at the same time, so it tends to be taught from
very early ages. In this line, authors such as Pogrund and Rosen proposed,
In 1989, its introduction with preschool children. A person who uses it skillfully
a cane can obtain a lot of useful information for moving around
independent. One of the most important pieces of information is related to
sound emitted by the tip of the cane - especially if it is metal - when moving
on the ground, when detecting obstacles that are found on the sides of the route
by which the subject moves.
Since the introduction of the cane as a mobility aid for the
blind people, many modifications have been made to increase their utility. Thus, by
for example, in 1950 Richard Hoover, from his experience working in a hospital of
war, designed a longer and more sensitive cane to contact with obstacles. He created
also a scanning system that allowed for greater safety for the visually impaired in their
displacements. Various modifications have also been made to the shape of the tip
to improve the detection of textures, curves, etc... However, the latest works
that have been carried out on the design of the end of the cane highlight
that there are no significant differences in the detection of curves or in the time it takes
used in the sweeping, when the tip of the cane is cylindrical, round, or curvilinear (The
Grow, Kjeldstad and Lewandowski, 1988.
More recently, the cane has been technologically innovated with the creation of the
called 'laser cane' or 'laser stick'. It is a cane of a length similar to
traditional, but it has the peculiarity of having a small part on the handle
vibrotactile transducer that provides the person using it with information about the
appearance and arrangement of the objects that are located at a distance of four
and six meters. Therefore, in addition to the advantages of the traditional cane, the 'laser' adds the benefit of
enable a much greater sweep and perceptual anticipation. Unfortunately,
the laser baton has a fundamental problem: it is an expensive instrument and
delicate that cannot be used in the same way as the traditional cane. As
The reader knows that the cane is also a protection system for the blind that prevents them from
to stumble upon obstacles and, consequently, it prevents falls and that, for this reason,
suffers all kinds of blows and deformations. Precisely, the traditional cane has a
affordable price and is easy to repair, so it can be used for these purposes.
On the contrary, the laser cane is very expensive and difficult to repair, which is why
It turns out to be a very little used help for the blind.
In the last two decades (Farmer, 1980; Weinstock, 1982; Coleman and Weinstock,
1984), a series of electronic devices have been appearing on the market that
they try to provide the blind -generally through acoustic aids- the information
space that cannot be obtained with sight. In general terms, it can be said that,
with this type of devices, it is intended to expand the natural possibilities that it has
auditory system in humans with artificial resources that allow the blind
to estimate distances, directions, and positions with greater accuracy. Consequently,
one of the most important functions that these aids attempt to fulfill is to provide
the blind a greater perceptual anticipation, in order to allow them to detect
objects and obstacles that are at a certain distance. Thus, the ultrasonic aids
provide the individual through auditory means, direct information that allows him to distinguish
and to identify concrete elements and shapes in space. Of all the aids
electronics available -- such as the 'path sounder', the 'mowat sensor', the 'step
sensor, etc.,- perhaps the "Sonicguide" is the most useful and complete device. This device
It is a dual-channel ultrasonic emitter that generates a continuous emission of ultrasound.
in such a way that, every time it encounters an obstacle, it sends an echo that returns towards
the walker. This echo becomes an audible stereo sound, which provides
different tones depending on distance, direction, texture, size, and location
spatial of the object that has been found, of
such a way that the tone that reaches the walker depends on all these variables. It
place in a fixed position on the subject's head and, therefore, the echo that it receives
it depends on the head movements I make. The signal it sends arrives in a way
separated to both ears and it is precisely the integration of both acoustic signals that
that allows the location of the object in space. Despite technological advances
that undoubtedly represent these devices, there are authors such as Foulke (1984, 1985), who
they show certain reservations towards them. The most general criticism that can be made of these
"help" is that they are not based on a theory of spatial knowledge that
serve as a framework. For example, before designing these devices, one does not
has determined what type of spatial information is critical and necessary for
to move well within a space, nor in which specific part of the environment it is located
that information.
As just pointed out, the designs of the 'ultrasonic aids' have not been studied.
previously, what are the sensory systems involved in mobility and the
displacement and, consequently, neither how one of them should be replaced
when it is deficit. The most commonly used method for transmitting the
spatial information with these devices consists of translating certain data from the environment to
auditory stimuli. This sensory modality has been chosen simply for reasons
techniques, without having previously studied the adaptability of hearing for
gather that information.
Thus, for example, the information that one of the devices can provide
previously mentioned, the 'sonicguide' is so extensive and complex that it would be very
difficult for any distinguished person to distinguish and interpret it without prior training
quite exhaustive. If an individual uses this device while walking, they receive
simultaneously three different classes of information about the objects it finds in
its path: distance, shape, and texture. Consequently, the complexity of the
the information that is received and must be interpreted is so much that it does not allow him to attend
simultaneously to auditory, tactile, kinesthetic, and proprioceptive stimuli - that
provides the environment naturally. It has been proven that blind people
they prefer to orient their movement according to the natural stimuli of the environment, reason
for which the use of the "sonicguide" is currently practically dismissed.
how it helps with the mobility of blind people. Regarding the localization of
The environmental stimuli that ultrasonic aids collect should be noted that, almost
all of them can only gather the information that is in front of the subject, and
never from the sides nor from below, from the ground where the individual walks.
However, as has already been said, perhaps one of the pieces of information that is most
useful for a visually impaired person and provides more security when moving comes from
the textures, incline, and position of the surface they walk on. There is none
ultrasonic assistance capable of providing the user, while walking, information -
about the surface that it will immediately cover. On the contrary, the cane
traditional, which has been previously mentioned, fundamentally collects that type of
information allows the blind person to explore the surface they are about to step on. It is
say, these modern devices, at least for now, have not been able to replace in
its functions to the old cane.
It is still worth highlighting some other problems that help explain the
the reluctance that the majority of people have towards the use of these devices
blind. On one hand, their excessive cost, but also, this type of devices are usually
relatively large, visible and eye-catching, which makes the individual who them
it presents a strange image to others that some people may
even consider ridiculous.
Despite the criticisms that have been made so far of the 'aid
technological" designed. so far to increase the orientation resources and
mobility that blind people have, we cannot provide the reader with a
extremely pessimistic outlook. We believe that, in the immediate future, the
the development of this type of devices is favored by the use of
advances in microinformatics to ensure that the data collected by them can
translate into information that can be easily interpreted and used by the
blind. For example, instead of translating environmental information into frequencies and
intensities of sounds hardly significant for the individual, would be very
it is convenient to use voice synthesizers that provide that data in a way
verbal.
To conclude, we can say, briefly, that the new technology should strive to
design aids with the following characteristics: a) that are easy to use; b) that
they do not require an excessively long and costly training period; c) that not
distract the subject so that they can perceive the natural acoustic signals of the environment.
Ultimately, that they really improve and noticeably increase the amount and
quality of the movements of blind people. .

3. The content of spatial representation in the blind

3.1. Organization of spatial representation

For environmental psychology, there are two ways in which, in general, people can...
organize or structure the locational information contained in its representations
spatial, in that complicated process of organization and recovery of a
spatial memory: through routes and through configurations. We talk about
route organization, when the representation contains information regarding the
sequential spatial relationships established between a point of arrival. one of
departure and the intermediate elements. It is the way, for example, in which we
we remember the routes we usually take every day. On the other hand, we refer to
a configurational organization when the representations contain information
of a dynamic nature that involves the relationships that each of the elements of
space maintains with the rest. It is the process we undertake when we want
relate different points in a space, for example, in a city, that usually do not
to be part of a route taken daily. Without a doubt, the organization of a
space through "routes constitutes a less complex level than the configurational
needs to execute fewer cognitive operations. The fact that an individual represents themselves in a
One way or another, a certain space depends on the complex interaction between different
characteristics of the space (size, complexity, etc.) and of the individual (age,
intelligence, personality, need, motivation, etc.), as well as transactions
that the subject usually maintains with the environment.
When we study spatial representation in blind people, this distinction
The structure of routes and configurations is very important. Many of the
works done on the subject have revealed that blind people
they have great difficulties in organizing their representations properly
configurational and
that, consequently, these tend to, almost always, be structured following a model of
routes. This relatively primitive way of organizing space would be determined,
to a large extent, due to the sensory limitations of the blind. As we know, the fact
knowing space through sensory systems that substitute vision implies
that the information must be collected in a sequential, successive, and fragmentary manner. For
this, important authors such as Fletcher (1981), Foulke (1982) or Slator (1982)
they consider that when vision is lacking, it is not possible to organize the content of the
coordinated and global spatial representations. If such a hypothesis were true,
this would mean that blind people would have their opportunities limited for
explore unknown spaces, to establish new routes and to make inferences
spatial.
However, the results obtained from our own research on the
development and the learning of spatial knowledge in blind people, we
they allow for more optimistic positions to be maintained. From them, we can believe we can assert
that some
adolescents and adult blind individuals, when they have enough experience with a
certain space, they can organize their representations in a manner
Configurational, they can coordinate all the points of a
space. This happens both when it comes to the representation of a known environment and
relatively
simple like the outer enclosure of a school (as seen in figure 5.1.)
as for another as broad and complex as the city of Madrid (figure 5.2.), always
that the appropriate procedures are used so that the blind can objectify and
communicate those representations (Huertas and Ochaíta, 1988; Huertas, 1989; Espinosa,
Huertas and Ochaíta, 1991). Another clear example that blind adolescents, even those
who have never had visual experience, are capable of organizing a space in such a way
Configurational is the one that follows. Once a new route is learned in a space
relatively complex formed by seven elements, always arranged in the same
sequence, :these teenagers were able to use new routes relating
those spatial elements in a route order different from the one they had learned, it
which, from our point of view, implies a configurational organization. This
it means that at least in circumstances similar to this one (with a number of elements
not very high, with appropriate outsourcing procedures, with absence of
dangerous or stressful factors for the blind, etc.) the visually impaired, by virtue of their
own interests, can abstractly and coordinately relate the relationships
spatial relationships that can be established among a set of environmental elements and inferred
the possible paths and roads that connect them, (Huertas 1989).
On the other hand, as stated in the introduction of this chapter, the representations
spatial elements contain information about the distances that exist between the elements
of the environment as well as on the direction or orientation of those elements. That is why
Some authors have studied the locational aspects of spatial representation.
in the blind analyzing their abilities to estimate distances and directions. A
we present to the reader the most important results obtained in these
jobs. They also study it -although in this case analytically- the
organization of the spatial representations of blind people.
FIGURE 5.1. Graphic representation of the actual arrangement of the elements of the
model of the school group, alongside the representation made by a 14-year-old girl.

FIGURE 5.2. Representation of the city of Madrid, after analyzing the

real distance estimates, through a scaling procedure
multidimensional

The method that is commonly used to know the capacity that subjects have
to estimate distances, it consists of asking them to evaluate or judge the length or
distance that separates objects from each other in a given environment. The already classic
researches that Hermelin and O'Connor published in 1975 and 1982 put forward
It is stated that blind people had more difficulties in estimating distances.
that in the localization of objects in space and that were much less precise and
effective in those estimates as the seers. Nevertheless, for the authors this does not
it meant that the blind were unable to estimate distances, as they could do so
(although with less precision) based, above all, on kinesthetic information,
proprioceptive and temporal.
When we talk about estimating distances, we can refer to two different types of
distances or paths: functional and Euclidean. The functional estimates
correspond to the distances determined by the actual length of the route taken
a subject to connect two points in a space that can include turns or detours
determined by the obstacles or objects encountered along the way. The
Euclidean estimates represent the straight-line estimation of the length of the
route according to the principles of metric geometry. Normally, in a space
In reality, functional distances do not usually match Euclidean distances. The
research conducted with sighted individuals has revealed
I state that there are usually no serious problems in estimating metric distances.
even in young children. The work of Kosslyn, Pick, and Fariello (1974) demonstrated that
preschool children could estimate both types of distances and that, even,
they preferred to make their judgments considering straight lines.
The different experiments that have been conducted with blind people (Lockman,
Rieser and Pick, 1981; Rieser, Lockman and Pick, 1980; Ungar, Blades and Spencer, 1991,
they have shown that they are capable of making functional estimates of distances
existing among the elements of a space, with a degree of fit similar to that of the
seers. On the contrary, the accuracy of the blind people's estimates was
considerably lower when they had to judge Euclidean distances. These
results align with the hypotheses proposed by Hennelin and O'Connor: it is the
visual experience that allows a subject to make distance estimations
Euclidean with precision. This does not mean that the blind, not even those who do not
they have had any visual experience, are completely unable to conceive the
geometric distances that separate the elements of a space, but when they are not
having visual experience, it becomes more difficult to estimate distances using measures
geometric that through other forms of measurement, of a more functional nature or
temporal.
The number of experimental works that have been published on the
the ability of the blind to estimate directions. Generally, these works seem
indicate that blind people have greater difficulty making judgments of
directions that provide distances. So that a subject can make a judgment about the
directions in which some objects are located must start from a framework of
stable reference. As we will mention in more detail in section 5, the framework
the main reference that the visually impaired use is their own body,
regardless of the spatial situation in which they find themselves and their relationships
with the objects that surround them. The seers, on the other hand, often use certain references
less egocentric, taking positions as a reference, undoubtedly more stable than
they have nearby objects. Therefore, some slight changes in body position,
they mean, for a blind person, very significant changes in the estimations of
directions.
To conclude, we believe it is necessary to point out that, despite the limitations that seem to
to have blind people when estimating directions, new ones are needed
work on this topic. They should use more complex procedures and
Objectives for these people to be able to express or communicate their estimates
of addresses they perform. In section 7.2 of this same chapter you can find
the reader some of these procedures.

3.2. The elements of spatial representation

When Lynch studied in 1960, the elements that different individuals included in
the representations of her city defined the existence of five great categories
prototypical elements: paths, edges, milestones, neighborhoods, and nodes. The paths are the
routes that the subject normally follows to connect the characteristic points of
environment, such as streets, roads, railways, etc. The edges are the
boundaries between two phases and constitute linear breaks in the continuity of space:
beaches, railway crossings, walls, etc. The milestones are the physical objects most
significant to the city and serve the individual as reference points, like a
building, a mountain, a certain business, a monument, etc. The neighborhoods are
those sections of the city, of medium or large dimensions, that have a
series of common characteristics, whether urbanistic or of meaning. And finally, the
Nodes are the strategic points in the city where several main routes converge.
Although the existence of these five classes of elements has been proven
empirically in various works (for example, Aragonés and Arredondo, 1985),
some authors prefer to reduce them to three: reference point, which includes milestone and
node, line or route that includes paths and edges, and area that, in a certain way, is
I would identify with neighborhood. In this way, we have a category of place or situation, the
reference point; a second sequential or successive category, the route; and a third
properly configurational, the area. These three categories of elements are the ones that
we are going to use for the study of the representations of the blind.
As we have already said, the paths are the routes or roads that the individual follows to
walk and are marked by the reference points or milestones. In the section
previously we pointed out how many of the scholars of spatial representation in the
blind people consider that these subjects are only capable of storing representations of
space formed by sums of different routes. We will address this topic again in the
next section when studying the 'spatial scheme'.
For a milestone to facilitate orientation and mobility in a given environment it must
to have, logically, a stable location in space and time, as well as some
certain physical characteristics that allow the individual to perceive it at a moment
determined. Unfortunately, it is much more difficult for a blind person than for a
The seer finds reference points in the environment that meet those characteristics. The
most of the environmental elements that a blind person can perceive, such as
for example, the noises from the street are not completely stable and permanent. Without
embargo, paradoxically the blind depend more than the sighted on these points of
reference to be able to orient themselves in large spaces. Specifically, they need to have
more landmarks when walking through a space because the
sensory systems they have allow for a perceptive anticipation of the
much smaller than that provided by vision.
Precisely because blind people need to use several points of reference
when they walk, it is useful to make a distinction between what we have called milestones, or
big landmarks, and the informative keys they take from the environment. From
according to Hill and Ponder (1976), the blind person includes in their representations
diverse spatial keys or auditory, tactile, kinesthetic, or olfactory information
that could be useful for them when moving and orienting themselves in a specific environment.
These clues are, for example, the different textures of the ground, the ambient noises, the
slopes and unevenness, the smells, etc.. Unlike the milestone, the key does not have to be
to be stable, constant and very significant, but is characterized by being dynamic and,
small, for being able to be used in different spaces. Of course, not all the keys
they are useful for the blind when moving through a space, some -that may have
have been useful in a certain path - they can be useless and even
provide false and negative references.
Finally, regarding the presence of areas in spatial representations of the
for the visually impaired, we refer the reader to section 4.1, where their possibilities were discussed.
to organize the different environments in a configurational manner.

3.3. The spatial schema and its functions

When a traveler moves along a route they do not know to reach a

determined destination uses both the information it receives from the environment during the
march, like the general spatial knowledge that one previously possesses. It is very
likely that this knowledge has the structure of mental schemes, that they are
summaries and abstractions of information that, on numerous occasions, the individual
I have needed to move, to analyze, and to understand the information
spatial.
As highlighted in section 3 of this chapter, blind individuals
They move through the environment with less security than the seers because the information.
the perception they have is lesser and less adequate than that of these. That's why, as we have
pointed out on several occasions, when blind people have to move around
determined environment depends, more than the seers, on the schemes or
spatial representations they already possess. This means that the blind rely more
that the seers, to cognitive anticipation to plan and carry out a journey.
The concept of spatial scheme makes sense, from our point of view, in the
measure is something that is used, that needs to be formed, that must be built almost
permanently and that must be used to guide decision-making during a
displacement. That is why it is important to take into account both its formation process
as its phase of application. In this regard, Foulke (1982 and 1985) hypothesized that the
elements that will be part of a spatial scheme (boundary markers, paths, etc.)
depend on the spatial information analysis strategies that the subject uses and
this, ultimately, is determined by the perceptual systems involved. The
information that may be relevant for a clairvoyant on a path (the vision of a
a monument, for example) may be useless for a blind person and conversely, something that can
being so inconsequential for a seer as the camber of a curve can be for a
blind the element that signifies the next arrival at a destination. For people
blind, the selection of these significant elements is a task prior to the
determination of the most convenient strategy to perceive them and manage to store them.
We can realize, then, that the process of forming a scheme.
spatial functionality is something more complex, explicit or conscious for the blind than for
the seers.
Once the blind subject has sufficiently constructed that abstraction that
we call spatial scheme, it must be used whenever a decision needs to be made
when taking a tour of a space. As we know, blind people must take
decisions almost constantly when they walk. So that these subjects can
to effectively use those cognitive anticipations, one must know how to take from their
the general spatial scheme precisely those aspects that are useful to him
to orient oneself in a specific space. But since the spatial schema is something dynamic
and changing, each new journey made by a subject expands and modifies it.
scheme.
In this same sense, the spatial scheme also allows the individual who possesses it
detect the mistakes made while walking. Consequently, it also serves to
prevent and then avoid the difficulties or dangers that may arise while traveling
a specific route. The individual uses their spatial scheme for this function when they
realization that there is a discrepancy between what one perceives at a given moment and their
memory of what I should perceive. This is how the blind preferably avoid.
the multiple risks they face in their movements. As their perception is
limited, they tend to anticipate and be aware of the obstacles, impediments, and dangers that
They can find themselves on their way, resorting to memories about the situation in
what dangers are usually encountered.
From everything we have just said, it follows that the blind need to receive
some type of formal instruction that helps them, both to build and to apply from the
best possible way their spatial schemes. Precisely, one of the main
objectives to be pursued through orientation and mobility programs
What was analyzed in section 3.3 must be the construction of spatial schemes.
that are useful for moving through the largest number of spaces possible.

4. Development of spatial knowledge

4.1. Development of spatial knowledge in the preschool stage

This section attempts to summarize the literature regarding development.

spatial knowledge in blind children. We begin this summary with the
research conducted in the preschool stage. The spatial development of children
the visually impaired in early childhood has been thoroughly addressed in the chapter
dedicated to psychological development, for which we refer the interested reader to the
sections 2.1 and 2.2 of that chapter.
Unfortunately, there have not been many works dedicated to the study of
spatial development during this period of the blind child's life. Furthermore, the greatest
some of them are limited to making mere descriptions of that development without contributing
explanatory models of it. Thus, in some works the problem has been raised
of the limited interaction that the blind child has with the environment and how this can
causing difficulties in the acquisition of their own body image as well as in the
understanding of spatial notions such as direction, size, distance, etc.
It has also been noted that this same lack of interaction with the environment limits the
understanding that the child has of general concepts that have environmental references
for example the topography and structure of your house or the street you live on, like this
like the objects and elements that compose them (Hapemans, 1967; Hill, 1984 and
1986; Hill and Blash, 1980). Hill's research has also indicated that the
blind children, in the early years of life, show space-time confusions,
that manifest, for example, in the confusion of the concepts 'here' and 'now'.
The understanding of the previously mentioned spatial concepts and relationships
acquired in the daily transactions between the child and the surrounding environment.
Hello, the perceptual restrictions that blind children have imply, necessarily,
that these transactions are different from those of the seers, both from the point of view
qualitative as well as quantitative. In any case, it should be noted that - as
It has been repeatedly stated in chapter 3 - the people surrounding the blind child act
as mediators in the exchanges between this and the environment, facilitating and
stimulating the exploration of that environment and the objects that are found in it. From
according to Scholl (1986), many of the difficulties that blind children have
to understand the physical environment in which they live, it may not only be due to blindness
but also, and above all, to the scarce mediation that their parents exercise when it comes to
to provide them with the necessary support for optimal learning and development.

One of the few studies conducted on the early development of notions

spatial, it is the longitudinal study by Landau, Gleitman, and Spelke (1981 and 1985),
carried out from a generative theoretical framework. These authors began to work
with a completely blind girl when she was 32 months old. At this age, she
they showed the spatial arrangement of four objects situated in each of the
corners of a room in a rhomboid shape. They found that this girl was capable,
just like a seeing child of his age, to connect those objects through routes that do not
they had been taught. As a consequence of this, the authors concluded that if,
from an early age, a blind child was provided with information about
the distances and angles between the elements of a given space would be
able to use this information together to create alternative routes and derive
new angular relationships.
The same girl, at 43 months, was able to combine her supposed skills.
about Euclidean space, to orient oneself perfectly in a room, as long as
I had some data that would serve as a reference, even though I couldn't estimate.
appropriately the distances between the elements of that room. At 48 months,
I was still not able to use auditory information -the echoes- to
to orient oneself. Landau, Gleitman, and Spelke explain this last result, arguing
that the blind girl found it more useful to orient herself using knowledge and the
spatial representation that it already had, which the information obtained through the echoes.
Finally, the authors state that at four and a half years old, the girl was able to use
a tactile map to navigate and understand, more or less adequately, an environment not
familiar to her.

Based on the data obtained from the research, Landau, Gleitman, and Spelke arrive at
two general conclusions that deserve to be highlighted. The first, in which we are
I totally agree, it is of a methodological nature, and it refers to the need for
adapt the study methods of spatial knowledge to the characteristics of the
blind children. The second conclusion -undoubtedly much more debatable- is of a nature
theoretical. The authors maintain that the spatial knowledge of any person,
seer or blind, is characterized by being generative, abstract, and fundamentally
Euclidean. Thus, human spatial knowledge, like language, would be
generative character. This generativity would become evident when, for example,
A traveler can find completely new routes to move around.
spatial knowledge would also be independent of the sensory modality with which
it takes the information; an amodal knowledge, not specifically visual or tactile. And
Lastly, this knowledge would be aligned with the principles of Euclidean geometry.
For example, from a very young age, people, even blind ones, would encode the
space as straight lines that intersect in a specific plane, according to a
Euclidean geometric framework.
It is undoubtedly surprising that a blind girl between three and four years old arrives at
understand, so quickly, Euclidean spatial relations. How we will study
subsequently, most of the research conducted on this topic places
this type of spatial acquisitions at much later ages. On the other hand, not
the idea of generativity of spatial knowledge is no longer open to criticism. Thus, authors
such as Millar (1988), who maintain empiricist conceptions of acquisition
such knowledge, they not only have doubts about the conclusions of Landau's work and
but also in relation to the credibility of the experimental results that
they support them. In this sense, Millar, once the detailed analysis of the
the routes that the girl made, she observed that the new routes that she herself deduced - and
the authors base a good part of their conclusions on - were not so straight or
Euclidean as maintained by Landau, Gleitman, and Spelke. Furthermore, it seems that the girl
he had certain visual remnants that he used for his movements, which would explain
a good part of the results obtained. Finally, the conditions have been criticized.
experimental work, especially the learning conditions, since they
provided the girl with great attention and affection, which served her to obtain a
more selected and carefully curated information than that usually available to other blind children in
similar conditions. From our point of view, these latest Critiques are not
acceptable, since, as we have repeatedly pointed out in the pages of this book, the
natural learning conditions at such early ages necessarily imply
emotional support and collaboration from adults.
In summary, we know very little about the development of space capabilities of the
blind children in the age range between two and seven years old. The work of
Landau, Gleitman, and Spelke is, despite the questions it raises, the only one that we
has been able to provide any information on the subject. Consequently, it is absolutely
essential to the implementation of research that examines in a way
systematic evolution of spatial knowledge in this stage of the child's life
blind.

4.2. Works based on Piagetian theory

The Piagetian theory of the development of spatial knowledge (Piaget and Inhelder,
1947; Piaget, Inhelder and Szeminska, 1948) is undoubtedly one of the first
coherent and structured approaches to the ontogenesis of spatial representation,
approach that has had a great influence on most subsequent studies on
the topic.
The fundamental postulate of Piaget and collaborators on the genesis of knowledge
spatial supposed that this is determined by the general cognitive development of the
individual. In this way, they analyze the acquisition of basic spatial concepts.
in children, following their classic stages of development: sensorimotor period,
the concrete operations (preoperational and concrete proper) and the period of
the formal logical operations.
Throughout development, the subject constructs three types of spatial relationships:
topological, projective, and Euclidean. The topological space is the simplest and it
fundamental in the connection of some elements with others based on relationships of
proximity or separation, order, enclosure, and continuity. More complex are the
Euclidean and projective relations, the former based on metric relations and
in those determined by the Euclidean coordinate axis (they can be the points
cardinal or any other system based on orthogonal coordinates and angles). The
The projective system is based on the knowledge and use of the point of view, of the
perspective, depth and height.
Between birth and a year and a half or two years of life, in the sensorimotor stage, the
the child will coordinate the three types of basic spatial relationships mentioned above.
But it is very important to emphasize that this will be done at a purely practical level and not
representative or symbolic.
Starting from around the second year of life, the child will begin to reprocess
those acquisitions in the realm of representation, in such a way that the handling
correct and the understanding of topological relationships: projective and Euclidean is going to
follow a long path that will not end until adolescence. In this way, the child of
Preschool, in the preoperational subperiod, begins to represent connections.
spatial relationships between objects according to simple topological relationships, such as those of
proximity-separation. Subsequently, it will handle the relationships of closure and
continuity. But until around the age of seven, it will not start to take into account.
the projective space, which implies the understanding of the variation of relationships
left-right, up-down according to the observer's position. Neither
until this age, he/she will manage Euclidean relationships such as those with some precision
involved in the management of horizontal and vertical reference systems, or in the
understanding of proportions or distances.
Between the ages of seven and eleven, during the concrete operational period, the child will go
little by little being able to understand that there are other viewpoints to place a
object or a group of objects. Thus, it will begin to understand, for example, 'what objects
three-dimensional, such as buildings, which we normally know from the
soil can be represented in two dimensions, taken from above. In relation
with the Euclidean space, the child will increasingly be able to orient himself through
natural reference systems, as well as using proportions or distances (although
not yet in a metric or mathematically exact way.
By the age of 11, coinciding almost with the access to logical thinking.
formally, will the child have the ability to understand spatial relationships of
total shape, using conventional coordinate systems. It is now, by
for example, when the individual is going to fully understand distances, proportions and
conventions that are represented on a map and, thanks to the emerging thought
hypothetical-deductive, to understand the existence of certain places and relationships
spatial matters on which it has not had direct space experience.
Studies on the development of the visually impaired based on Piagetian theory,
(Bims, 1986, Ochaíta, 1982, 1984; Stephens and Grube, 1982) highlight the
existence of the following sequence of acquisition of spatial knowledge in the
blind children from birth. Around the age of 11, they are able to
understanding topological spatial relationships, which are also the simplest
for the seers, although the latter acquire them around the age of 7. The relationships
Euclidean metrics (horizontal-vertical reference systems, parallelisms, angles,
etc.) would be accessible for the blind from the age of 14, with a delay of five to
six years compared to the seers. As is easy to assume, in the absence of vision, it is not
possible to have a direct or perceptual knowledge of the projections of objects,
from the perspectives. However, as can be seen in the graph of figure
5.3., the previously cited investigations allow us to affirm that the blind, starting
From the age of 14 or 15, they can begin to understand problems of perspective on a small scale.
scale, like the one posed in the typical Piagetian task of the "three mountains", using
non-projective spatial relationships, but metric or Euclidean. The most conclusive
important that can be done from these works, is not to influence the aspect
negative aspect of the delay of blind children compared to sighted children, but in
highlight the positive aspect that, without a doubt, means that the visually impaired are capable of
to come to understand the spatial relationships involved in this type of tasks.

FIGURE 5.3. Development of perspective coordination according to age level.

4.3. Development of spatial representation or 'cognitive maps'

In this section, we aim to analyze the research whose objective has been
focused on studying how blind children and adolescents develop the ability to
represent themselves in the different environments in which they usually move, like their own
house, their neighborhood, or their city. As we will see below, despite the fact that the development
has proven to be a fundamental factor when determining the capacity of a
An individual has a certain space to represent themselves, very few works are available.
that have adopted an evolutionary approach to studying spatial knowledge in the.
blind people.
The most classic works on the development of spatial representation are the
carried out by Hart and Moore (Hart and Moore, 1973; Moore, 1974). From a framework
theoretical "interactive constructivist" and taking as a reference the research
piagetian, these authors propose the existence of three stages or successive phases in the
development of the representation of an environment. The development and, therefore, the sequence of
the stages are manifested in the change of the frames or systems of reference that the
children use when representing a specific space. We will describe next
the most important aspects of each of these stadiums:
Between the ages of four and seven, approximately, children build their maps.
through egocentric and undifferentiated reference systems, focused on the self
child. Thus, they only represent the places that are familiar to them, such as their home or
school, without taking into account the projective spatial relationships (left
right or in front-behind in relation to the observer's point of view), nor the
Euclidean (horizontal-vertical coordinates, proportions, and distances). The only
spatial relationships that the child takes into account are topological, of a more contextual nature.
primitive.
Later, from the age of seven, children organize their maps according to
partially coordinated reference systems in fixed groups. In this way
they structure their representations in groups (like the elements that are found
around their house, their school, etc.) that, internally, have relationships
Euclidean and projective quite exact, but that coordinate with each other in a more
imperfect, through spatial relationships of a primitive or topological nature. By
last, from
the 11 years (at the end of the period of concrete operations and at the beginning of
abstract thinking), the subject will be able to organize their maps into systems of
abstractly coordinated references, which implies projective organization and
Euclidean distance of the different groups represented on the map.
This evolutionary sequence has been experimentally demonstrated in numerous
Research conducted with sighted children. Specifically, in our country, there have been
carried out a series of interesting works in different environmental settings, which have
confirmed the sequence of the spatial representation development proposed by Hart
We refer the interested reader to the research of Aragonés (1988),
Espinosa (1990) and Martín (1985).
On the other hand, Moore found that this sequence of stages also occurred when
the individuals had to learn an unknown space. In a work done with
English adolescents (1973), found that when a person with a development
operational-formal cognitive had to learn a completely unknown environment and
complex, went through the three previously described stages until reaching, in a more or less
less fast, to be able to use a coordinated reference system.
The data we have on the development of spatial representation in children and
adolescents with severe visual difficulties are scarce and not very rigorous. Most
of the research conducted with the visually impaired seems to disregard the influence of
development in the spatial competencies of the subjects. It gives the impression that their
authors believe that children between the ages of five and fourteen only differ from the
adults who lack the amount of experience and instruction necessary to
to have adequate spatial knowledge. However, works such as those of Hart
and Moore (o.c.), with a broad empirical and theoretical base, allow us to assert that the
spatial knowledge is fundamentally determined by changes,
both quantitative and qualitative, that occur throughout ontogenesis.
Until the completion of our own work - which we will mention below - no
author, as far as we know, had studied the development of spatial representation in the
blind children using the theory of Hart and Moore as a reference frame. Without
embargo, some research has used terminology inherited from such theory,
only to explain their experimental results. Thus, for example, Dodds,
Howard and Carter conclude, based on the data obtained in their 1982 research,
that the majority of 11-year-old blind children studied represented a
determined environment with clearly egocentric drawings. Likewise, other works
conducted with blind adults or adolescents, have highlighted the difficulties that
these have to reach the final stage of the development of the representation
spatial, that is to conceptualize and represent a space in a coordinated manner,
although this is known (Casey, 1978; Warren, 1984) However, despite
the theoretical problems raised by these investigations and the negative conclusions about
those that arrive in relation to the spatial competence of blind people, must be
It is worth highlighting that, in practically all of them, some blind individuals were able to do
coordinated spatial representations that are, consequently, quite accurate.
It is important to note that many of the works we have just cited use
terms such as egocentrism, taken from the works of Piaget and his followers,
it is very common to encounter the egocentric-alocentric dichotomy established
by Flavell et al. in 1968. The use of these terms outside the theoretical framework in the
that makes sense has led many authors -especially Anglo-Saxons- to constrain
its meaning is reduced to almost two types of spatial coding strategies:
internal and external. It is considered that the former, more primitive, imply the use
primordial of the corporal keys of the individual to organize the space and, without
embargo, that external coding strategies are more perfect as they are based
in the use of referential elements external to the subject. From our point of
view, reduce the meaning of the terms egocentric-alocentric to mere strategies
of coding, is far from the true meaning that these terms had
within the theoretical framework from which they emerged.
Our own work team has recently carried out an extensive and
complex research, among whose objectives was to know the
characteristics of the development of spatial representation in blind individuals
(Huertas, 1989; Huertas and Ochaíta, 1988; Ochaíta and Huertas, 1988; Ochaíta, Huertas and
Espinosa, 1991). The sample consisted of blind children and adolescents of ages
aged between eight and eighteen years, without visual remains. These subjects had to
to learn, in four sessions, the arrangement of a series of elements that formed
some initially unknown routes (figure 5.4.). At the end of each session of
learning, the subject had to communicate to the experimenter the representation or the memory
that he had obtained from the route he had traveled, through two procedures
different: the construction of a scale model and the verbal estimation of the
existing distances between the elements of the route.

FIGURE 5.4. Sketch of the route to be learned in the small and large space.

Taking as a reference the stages of Hart and Moore (1973), our results
allow to understand, with some clarity, the development of spatial representation in the
blind people. As can be seen in figure 5.5, despite that development it
produced continuously -using the stages proposed by the aforementioned authors-, it is
the age of 13 or 14 years, which roughly corresponds to the beginning of adolescence, the
what seems decisive in the evolution of the spatial knowledge of the blind. In
In any case, our data shows that it is already well into adolescence,
approximately at the age of 18, when blind youth may have acquired a
broader development of the competencies to represent a known environment,
corresponding this moment with the full acquisition of a type of thinking
abstract or formal. This sequence of development of spatial representation agrees
with the data obtained from other work carried out by our research team
(Rosa et al., 1986; Ochaíta et al., 1988 a and b). As we pointed out in the chapter
dedicated to psychological development, it seems that the possibility of using a thought
formal -or propositional verbal-, allows the visually impaired, starting from adolescence,
"remedy" many of the problems that the lack of the visual channel produces in access
to figurative thinking. .
Consequently, despite the peculiarities that the transactions present between the
blind individual and their environment, we believe we can affirm that, starting from adolescence, the
blind people can be able to structure a known space in a way
abstract and coordinated, possibly equivalent to that of the seers in their aspects
functional (see figure 5.8). In this sense, our conclusions contrast with the
from other authors such as Foulke (1982) or Slator (1982), which - as mentioned in the
section 4.3. of this same chapter-, they consider that the blind have
difficulties, even insurmountable, to create global configurations of a space and
that, consequently, can only represent such space through the
coordination of known routes.

FIGURE 5.5. Evolution of spatial organization in the 1st and 2nd session.
Finally, we would like to point out that, according to our study, the development of the
spatial representation in blind children and adolescents goes through the same stages and
follows the same sequence as authors such as Aragonés (1988), Hart (1979), or Martín
(1985) they have described for the seers. Indeed, as can be seen in figure 5.5. thus
As in figures 5.6., 5.7. and 5.8., the age of acquisition of these stages is
delayed in blind children, especially in the early age levels.

FIGURE 5.6. V(10 years). Egocentric stage. Clusters = 2. Mere relationships

spatial by proximity

FIGURE 5.7. M (11 years). Fixed/egocentric stage. Clusters = 3.5.

Adequate topological organization.

FIGURE 5.8. N (14 years). Coordinated Stage. Conglomerates = 5. Organization

5. The different factors that determine spatial representation

The reader who has proceeded orderly in the reading of this chapter will have been able to
realization that the representation an individual --blind or sighted-- has of a
concrete environment is determined by the complex relationships that occur among
different factors or variables. The variability of spatial representations that
the characteristics of people originate from the complex transactions that take place between the
own subject and the space in which it moves. Consequently, what we call
spatial representation is the result of multidirectional relationships that are
they are produced between a certain subject with cognitive and affective characteristics,
motivational and social traits that are unique to him and a specific space with certain
peculiarities that define it, such as size, complexity, and historical significance
social
We are aware that, from a transactional approach to psychology
Environmental, the study of the relationships between the individual and the environment must be taken
globally. Consequently, the factors that at any given moment determine the
representation that a certain subject elaborates of a specific space should not
to separate and study in isolation, but taking into account the relationships
complexities that arise among all of them. However, most of the
research that has been conducted in the area of environmental cognition has studied
in a isolated and unidirectional way the impact they have on representations
spatial factors or variables related to both people and the
space to be represented. Thus, the dominant perspective in the study of cognition
environmental, both in the blind and in the sighted, has been termed by Áltman and
Rogoff (1987), "interactional." According to her, researchers have studied
separately the incidence of different variables considered independent and
related to both space (size and complexity) and the subject (age, personality,
etc..) in the knowledge or environmental representation that is considered as a variable
dependent.
In the following pages, we review the existing literature on the factors that
they determine the representation of blind people. As has already been said, almost not
there are researches that address this topic globally, but instead study the
incidence of each of those factors separately in spatial representations
of the blind. Therefore, we will independently analyze the incidence of the factors
studied in the spatial knowledge of the blind. In any case, the reader must
take into account that, for example, the visual experience that a certain individual
had been able to have before losing vision, does not have a unidirectional impact on the
spatial representation of a subject, but rather produces effects on many other factors,
like motivation, personality, spatial experience, etc., all related
they with the representations.

5.1. Learning and Development

The experience or familiarity that an individual has with a certain environment has
considered one of the most important factors when explaining the
differences between the representations that different individuals have of that space.
Anyone can intuit, without the need for research on the subject, that the
the representation one has of a very familiar and known space is much more
complete and organized than that of another barely visited. The data
Experimental results obtained from sighted and blind subjects reaffirm that assumption.
As we said in previous pages when studying the stages through which the
ontogenesis of spatial knowledge, Moore (1975) in a research conducted
with sighted adolescents, it highlighted that the learning process of a
new environment reproduces the sequence of these stages. In 1983, Hollyfield and Foulke
they obtained results similar to those of Moore in a research conducted
with blind adults. These subjects had to learn, in a series of sessions, a
a determined route through an urban environment. As the sessions progressed,
learning and
as the subjects were gaining more experience with the route, they were becoming capable of
use a greater number of elements to externalize the representations of that route,
as well as to establish more complex and precise relationships between such elements.
Facing an unknown space has very different implications for a
blind person compared to a seer. In the absence of vision, the fact of not knowing
sufficiently a place implies a considerable degree of anxiety and stress. When a
blind person travels through an unknown place not knowing what dangers they may encounter there
place and, what is even worse, does not know if it will be able to perceive them in any way
to avoid them. If we add to this the fact that the blind person has to take the
information about that environment slowly, successively, and sequentially seems logical
to think that, in the absence of vision, knowing and understanding will be slow and complicated
organize an unfamiliar space.
There are very few studies, even in seers, that address such an aspect.
important as the relationship between learning and the development of spatial knowledge, is
to say, to analyze the effect of learning at different stages of development.
In 1987, Warren conducted a microgenetic study with blind children.
preschoolers of which, unfortunately, we only know a verbal report. These
Children were to learn a route in different sessions. Three conditions were established.
different learning experiments, which consisted of using different types of
help. In the first case, the children used an ultrasonic device during the
route, in the
secondly, a series of auditory cues were placed at different points of the
route, in the third group the usual mobility instruction techniques were used.
The initial results of the work showed that the children, in the last two
experimental conditions and as a consequence of learning, they were able to
change the level of your spatial organization, moving from a primitive organization
egocentric to another coordinated in a more abstract way.
On our part (Huertas, 1989; Ochaíta; Huertas and Espinosa, 1991), in the
in research already cited several times, we have studied quite extensively the
relationships that exist between the ability to learn a route and the level of development
of the blind subjects. We worked with a total of 40 blind children and adolescents from
between 8 and 18 years old, divided into four age levels. As for the
learning incidence, our data showed that in all age groups
studied, the subjects changed the level of their spatial representations as
that increased the learning sessions. As can be seen in table 5.2.
the average profit that was produced between the first and fourth session was
corresponding to a sub-stage, according to the development sequence of the
reference systems proposed by Hart and Moore (1973). If we analyze the relationships
between learning and development, our data allows us to assert that, at least with
In our experimental conditions, learning does not reduce the differences between
the age levels. Once the learning sessions are completed, the
corresponding representations of individuals at different age levels, followed
having the same differences between themselves as those observed in the first sessions.
Consequently, our results allow us to conclude that - with the procedure of
learning that we use-, the influence of learning on representation has its
limitations. Age and perhaps more specifically, the degree of cognitive competence
associated with it, conditions the possibilities of knowledge and
representation of an environment in a blind person. For example, in conditions
Learning similarities, an 8-year-old child will not come to know and structure space.
of the
the same way as one of 13. Thus, from the data of our work it is deduced that the
microgenetic advance is limited by ontogenetic development. Therefore, our
data matches those obtained in the main learning experiments of
operational tasks (Inhelder, Sinclair and Bovet, 1974), and with those from the research of
Moore (1973), on the microgenesis of spatial representation.
We cannot, however, dismiss the influence of learning on representation.
spatial awareness of the visually impaired. Even with a poorly directed learning process and
based on the personal action of each individual, like the one used in our work and,
consequence, without the need for complicated instruction programs, blind children
they learned the route of the proposed path. Consequently, the
blind people can, just like sighted people, enhance their abilities to
to structure a certain environment in a fairly autonomous way or, in other words,
using the most natural interaction mechanisms with it.
To conclude, it is important to highlight that the data just presented about the
relationships between learning and development in blind people cannot
generalize to other learning conditions. Possibly with designs of
more complex instructions and/or with a greater number of learning sessions, the
the influence of this factor would have had a greater impact on the capabilities of
spatial representation of the visually impaired. Therefore, we believe it is necessary to carry out
new research that studies the impact of learning on capacities
knowledge and spatial representation of blind children and adolescents.

5.2. The visual experience

In contrast to the factors of development and learning that have just
analyze, much space has been devoted in experimental literature to studying the
the incidence that previous visual experience has on the ability of the blind to
move around and get to know the environment. Logically, having had experience with the
space through the spatial sensory system par excellence - vision - can
to condition the type or level of representation that a visually impaired person has of a certain
environment. However, we cannot say that the visual experience facilitates, in a way
clearly, the mobility and spatial knowledge of the visually impaired. The research
conducted on the matter offer contradictory data, which are not always favorable for
the late blind. Precisely from the review of those investigations we can
to conclude, in general terms, the following. Having had visual experience prior to
blindness facilitates spatial representation when it comes to a complex space,
whose representation is evaluated through also complex responses, of which
then the level of coordination or global configuration that the subject has is inferred
space. In this same sense, Fletcher (1981) and Hudson (1984) found no
differences between early and late blind individuals in the representation of structured spaces
not complex, like those that involve a sequential or route-type knowledge.
For our part (e.g. Huertas, 1989), we have not found any significant differences.
between early blind and late blind in the previously cited research,
as can be seen in table 5.1. This may be due to the space that the
subjects had to learn was not very large or very complex, as it consisted of a
path formed by seven elements. Precisely, any path is usually represented by a
sequential mode, which may justify the lack of visual experience, if
we take into account the general conclusion mentioned in the previous paragraph.
However, it is important to point out that there are experimental works in which there has been
highlighted the ability of early blind individuals to create representations
configurations of a complex space. McLinden conducted a review in 1988
of these jobs concluding that 25% of the subjects who had never had
visual experience, they were capable of generating such representations. It seems evident, due to
so much so that there are great individual differences in representational abilities
spatial abilities of the early blind. Therefore, it would be appropriate to conduct new studies on
research that delves into the study of the causes that positively impact
in the representational abilities that some early blind individuals have. This
would allow for the later design of intervention and instruction procedures for
increase the knowledge and spatial representation capabilities of a large number
of blind people.

Table I.- Average scores of route reconstruction, by means of a

model, in the first and last learning session of the journey. taking into account
the different age levels

It is important to keep in mind that the level of knowledge or representation that a

An individual's space is also determined by a set of factors.
related to its physical characteristics. Of all of them, the size and the
complexity is what has the greatest impact on the ability of sighted individuals
-and even more in that of the blind-, to know and represent space. As it is
obviously, size and complexity are often two closely linked factors in the
natural environments, although researchers have sometimes paid special
attention to one of the two factors.
The various authors who, like Foulke (1983), Rieser, Lockman, and Pick (1980), have
studied the incidence of space size on representative capacities
from the blind, they have obtained matching data. The blind achieve better
results when research is conducted in a small environment, such as a
laboratory or a room, which when it comes to large spaces, like a neighborhood or
a city. Warren (1987) considers that it is rather the complexity of a
determined
space and not its size, which makes it difficult for the blind to represent it. Thus,
for example, the representation of a space with fixed dimensions would result in a more
difficult as the number of elements and relationships increased
spatial ones that configured it.
The data obtained in our own research (Huertas, 1989) seem to corroborate
the Warren hypothesis. Of the 40 children and adolescents that made up the sample, the
They should learn to represent the corresponding route to a small space.
located in the outer area of the school, while the other half learned the route in
a larger space, a public square. Despite the differences in size of
The two routes, both were formed by the same number of 'markers' - seven - and the
the spatial relationships involved between them were of the same difficulty. Not
we found differences between the abilities of our subjects (early blind and
late) to learn and represent the space formed on each route.
But, as we said at the beginning of this section, it is completely artificial to study from
separate and unidirectional the incidence of the different factors on the
representative abilities of the blind. In relation to this, another one of the
research carried out by our team (Espinosa, 1990) has revealed
that the blind can have very adequate representations of a space so
broad and complex as that corresponding to the urban environment of Madrid. But this
it only happened when they had developed sufficient cognitive competence, and when
they were very familiar with the city.
Finally, I want to reiterate that the capacity an individual has to know and
representing a space is determined not only by the quantity but also by the
quality of the transactions that occur between that individual and the space. Undoubtedly,
the lack of vision gives rise to particular transactions between the blind individual and the
environment that surrounds it, generating peculiar forms of relationship with space. For
for example, when we say that a blind person knows and represents a complex environment
like the city of Madrid, multiple factors come into play that, until now, have not
considered jointly by the different researchers. In addition to
those who signed up for Espinosa's work, it would be necessary to take into account, for
example, the motivation that drives individuals to
moving around the city, the meaning that city has for them and the different
neighborhoods that make it up, the history that each individual has of spatial learning,
etc...

6. Methods and techniques for outsourcing spatial knowledge

According to Evans (1980), the most important methodological problem faced is

finding environmental psychology has been about finding the right methods to
to objectify or externalize the knowledge or representation that individuals have of
a certain environment. Of course, it is difficult to come up with a methodology
that is valid to determine what type of memory, representation, or structuring
A person has created a space. Logically, if we want to advance in the study of
Spatial representation must continue to be a priority goal for us.
the study of the methods or techniques that allow us to objectify the representations of
the different subjects.
Siegel stated in 1981 that any objectification of spatial knowledge implies
a 're-representation' of that knowledge. For an individual to remember or be
represent the spatial activity that has taken place in a given environment, it must
make a first transformation or mental operation. When that subject also
pretend that other people access their own representation and have to
to externalize it in some way, a second transformation occurs. Precisely,
the fact that they involve a double representation by the subject makes it difficult
considerably both the design and the analysis and interpretation of the different
procedures for outsourcing environmental knowledge. In a similar sense,
Gauvain and Rogoff in 1989 point out that when scholars of environmental cognition
they talk about 'outsourcing' or 'objectification', they are actually referring to the fact
to communicate spatial memory through the conventions it uses for this
determined culture.
The problem becomes even greater when we try to objectify representations.
spatial of the blind or, to put it in the words of Gauvain and Rogoff, that they communicate
such memories through conventional systems. As we will analyze below
it seems more appropriate for the blind to use linguistic conventions when
communicate their spatial representations. On the contrary, the conventions
of a cartographic type -especially the drawings- are less suitable for the
people with severe visual impairments. In any case, it seems essential for the
psychology of blindness to have good procedures that allow us to
to know the spatial representations of the blind. As we already know, lacking
of a sensory system as important for spatial knowledge as vision,
it implies that it is precisely the area of mobility and spatial knowledge one of
those that require more specialized instruction. As we mentioned in section 3 of this
same chapter, one of the requirements that a good program must meet
instruction in orientation and mobility is based on having good procedures for
evaluate the results obtained. In the same way, we also remind the reader that
It can be very useful for teachers of such programs to evaluate the effectiveness of the
programs using techniques that allow for the objective representation of representations
spatial of
the blind.

6.1. Global or cartographic procedures

With this type of procedure, the subject is asked to create a certain graphic sketch.
of the main elements contained in a more or less known area, as well as of
the spatial relationships that those elements maintain with each other. The representations
such objectives are subsequently evaluated by various judges according to certain
pre-established categories.
Undoubtedly, drawing has been one of the most used techniques for people to...
seeing people can communicate the knowledge they have of a certain
environment. Interestingly, some researchers have attempted to adapt certain techniques of
drawing to be used when studying spatial representation
of the blind. For example, Dodds, Howard, and Carter (1982), adapted a device
special drawing of geometric shapes for blind people, the 'Sewell Raised Une
"Kit", with the aim of allowing a group of 11-year-old blind children to represent a
familiar environment. As expected, the blind children from birth obtained
very poor results. These results cannot be attributed to problems
representational, since, in no case, can they be considered alien to the logic of lack
of graphic skills that people who lack visual experience have. A
these problems must include those arising from the limited knowledge that they have
children of geographical conventions and how unfamiliar the use is for them
of
drawings and cartographic maps. Of course, the use of this type of conventions
For the blind to communicate their spatial knowledge is quite inadequate.
Some authors have tried to address the problems that lack of vision entails in
the understanding of cartographic systems using tactile maps. Just like the
visuals, these tactile maps are used for the visually impaired to learn the
spatial relationships contained in a map and, subsequently, transfer them to space
real that represents. The results obtained through this procedure have been
contradictory. In the works of Carreiras and Codina (1990), as well as of Herman,
Herman and Chatpman (1983) found that blind individuals were able to deduce quite
precision the spatial configuration of an environment based on a map, that is, of
transfer the spatial relationships of the map to a real environment. In contrast, Fletcher
(1981), found no usefulness when he employed these learning procedures. The
discrepancy between some and other works may be due to the number of objects and relationships
spatial elements presented in each of the models or tactile maps: only four
elements in the initial investigations reported and more than nine in Fletcher's.
It seems to be inferred that if we want tactile maps to be useful in
utility for blind people, should not include the representation of a very number
elevated elements.
Without a doubt, the global type procedure that is most commonly used, both with people
blind as seers, it is the reconstruction of the spatial arrangement of the elements
of an environment through models or mock-ups. This is the preferred technique in studies
evolutionary for the simplicity and appeal it has for children, even when
they are very small. Casey (1978), Hollyfield and Foulke (1983) and Passini and Proulx (1988),
They have used models to objectify the spatial representations of the blind.
precocious, without this procedure posing them communication difficulties. Also
we have used this technique in several works (Huertas and Ochaíta, 1988;
Huertas and Ochaíta, 1992), thus being able to verify its usefulness in assisting children.
blind people to communicate their spatial representations. The models usually
contain much less conventional symbols than maps and also very
accessible to be explored through touch. For children, they are quite
comparable to toys as they attract their attention and are very motivating. Therefore,
Hello, we think this could be one of the most useful techniques for you.
professionals dedicated to teaching mobility and orientation in children
the blind can assess the progress of their students. The reader interested in knowing about
more detail on the research that uses models to study representations
of children, one can refer to the works of children's spatial cognition carried out by
Aragonés (1988) and Martín (1985) with psychics, as well as by Huertas (1989), with children
blind.

6.2. Analytical Procedures

There are other methods aimed at making blind subjects
communicate their spatial representations through analytical techniques.
With these techniques, it is not necessary for the subject to simultaneously remember the
relationships between all the elements that shape a space - as happens in the
globals, but only those that involve two or three of those elements. Therefore,
It is intended for the subject to successively and partially express the distances and/or the
directions in which the elements are situated according to their own
spatial representation.
The most commonly used technique is distance estimation. With it, the subject is asked
that judges the distance that separates the different elements of a certain environment. The
the subject can estimate distances in metric form, using any unit of
measured in units such as meters or kilometers. It can also be done through
ordinal procedures for comparing distances, such as the estimation of judgments
of closeness or proximity. There are already quite a few studies that have examined the
environmental cognition in the blind through estimation procedures
distances (Espinosa, 1990; Huertas, 1989; Lockman, Rieser, and Pick, 1981). In all
it has been proven that blind people have no difficulties
important for estimating the distances involved in a certain space, on
everything if they are not required to perform very rigorous metric calculations.
Distance judgments provide us only with information related to the
the way in which the individual represents the existing lengths between the elements that
they form a space, but not on the relative positions that such elements have
in that space. This means that if we only have data related to the
distances, we cannot position the elements of a space in a configuration at
less two-dimensional that corresponds to the hypothetical cognitive map of the subject.
However, there is a statistical procedure, multidimensional scaling.
(MDS), which allows obtaining a global configuration based on the estimates of
distances that subjects perform, a procedure that, in certain cases, can be
very useful.
MDS is a multivariate technique developed in the mid-1960s, which
shares the same mathematical models as factor analysis and discriminant analysis.
It tries to measure or find the relationship between stimuli or objects (not between subjects as such
they do the factor and discriminant analysis), when the basic concepts are missing or not
the underlying dimensions are known (Hernández and Carreiras, 1987). In the field of
spatial representation, authors such as Rieser, Lockman, and Pick (1981), use
MDS to determine how people represent relationships among all
elements that configure a space. For this, the MDS collects all the combinations
possible distance judgments, considering the nearby or similar scores of
each of the elements that constitute the space with respect to all the
others. The final product of the MDS is, as can be seen in figure 5.9., a
global spatial configuration that represents both the position and the distances between
the different elements that make up the studied environment. This configuration allows
the researcher determines the degree to which the representation of space that the subject
it is consistent with a metric. The procedure eliminates many of the
problems of global methods: for example, the subject does not have to adapt to the
scale in which the model is reproduced, does not need to be familiar with
the objects represented in it, nor does it have to possess a certain level of skills
graphs. But, above all, it has a fundamental advantage, which is that it is a technique
which is easier for the subject than any of the cartographic ones. And this is
explain why this has to estimate only the distances that exist between the
elements without taking into account, simultaneously, the direction or position that they
They occupy the space. It is the own multidimensional scaling procedure.
which subsequently provides us with the position of the elements and their distances in
a global configuration: .
Focusing more on our field of study, this procedure has a series of
added advantages that are important for the study of spatial representation of
blind people. It is a technique that only requires the subject to do
verbal judgments of distances, is not loaded with visual aspects and, consequently,
does not determine a priori an unfavorable bias against the blind. Furthermore, the task is
it is done sequentially, so that the blind individual does not need to
keep present, at all times, all existing relationships between the
elements of space. It is enough for it to retain and estimate the relationships each time.
linear between two, or at most three, of those elements. It should be noted that in
absence of a sensory modality that -like the visual- allows for perceptions of
global character, the permanent retention of the configuration of a space can
surpass the cognitive competencies of the subject.
Distance estimates have been used, almost always, as techniques for
to understand the spatial representations of adults. However, it also
they have been employed in work with children. In this last case, always use
non-metric units for making distance judgments, such as for example
they are the estimates of proximity and separation. In any case, and despite the fact that
authors as relevant as Kosslyn, Pick, and Fariello (1981) have published
research conducted with this technique in preschool children, our own
experience in its use with child populations leads us to advise against it in
ages
, very early. Especially because it is a procedure that requires - mainly
when metric units are not used - the making of a large number of judgments of
distances by the subject, since only in this way is it possible that, sequentially, the
the subject combines and relates all the elements of the environment. This leads to the fact that
the data collection is long and tedious, quickly tiring younger children
from 9 to 10 years old. In any case, the results of our own work (Huertas and
Ochaíta, 1988; Huertas, 1989; Ochaíta and Huertas, 1992), allow us to conclude that, starting from
At this age, blind children are perfectly capable of communicating their
spatial representations through verbal estimation procedures of
distances.
Despite its usefulness, the treatment of distance estimates using MDS,
it currently has certain problems or limitations. Among them, it is necessary to highlight the
difficulty that for the subjects means, especially due to their scarce psychological reality, the
make distance estimations using Euclidean measurements - which are the most
suitable for further treatment with MDS-. On the other hand, it should be considered that the
the accumulation of statistical errors is greater when the subject has performed a number
little judgments of distances, which means that the more it is simplified
the data collection, the entire procedure is likely to be less accurate. In addition,
Unfortunately, the use of these techniques has not yet become popular, perhaps
because certain statistical knowledge as well as computer skills are required
relatively powerful. However, the fact that the MDS is one of the
statistical procedures that can most easily bring us closer to the hypothetical
spatial representation of an individual based on their distance estimates,
convert the combined use of distance judgments and MDS into one of the
most promising outsourcing procedures for spatial representation in the
scope of the psychology of blindness.

FIGURE 5.9. Representation of the city of Madrid, by an adult blind person, after
analyze their distance estimates through a scaling procedure
multidimensional.

Let's now turn to analyze the second of the analytical procedures, estimates.
of addresses. The techniques that experimenters most commonly use to
evaluate the positions in which the subject places the objects that configure a space, are
the "triangulation" and the "projective convergence". The most ancient in its
the use by environmental psychologists is triangulation, which consists of
in which the individual assesses the position that an object has in the environment, either by means of
a kind of telescope, well with a marker of angles. The subject must perform the
estimation of the position of a certain object from three different places, from
those who cannot see the object whose position is to be estimated, in such a way that, finally,
what is obtained is the way in which it locates the object at the convergence of the three
directions that it has marked. The technique of projective convergence completes the
previous procedure adding a distance judgment for each estimation
directional performed.
In the reviewed publications on the psychology of blindness, we have not found
research that studies the capabilities of the blind to estimate the
directions, using complex techniques such as triangulation or convergence
projective. Generally, researchers limit themselves to asking the blind to
indicate with a marker, from a certain position on a route, the place where
the preceding or following element that delimits that route (Herman, Chatman
y Roth, 1983; Hudson, 1984; Rieser, Guth and Hill, 1982; Rieser et al. 1985). The
results from these authors seem to indicate that, as previously mentioned in section 4.2, the
Blind people have more difficulties than sighted people in making estimates of.
directions, even though the orientation biases of some and others are the same
type. In any case, the worst performance by the blind may be due to that
the skills involved in orientation are more related to experience
visual that the necessary ones for the estimation of distances. From our point of view
the results that have just been reviewed cannot be considered definitive due to the
simplicity of the technique used. It is possible that, using procedures of
mental triangulation and projective convergence, richer data was obtained and
objectives. In this sense, we believe that such research is necessary to
to deepen the abilities of the visually impaired to estimate directions.

6.3. Verbal descriptions

One of the oldest procedures used to understand representations

spatial descriptions of the subjects have been verbal descriptions. They consist of asking the
subject who describes, either freely or through a questionnaire, the knowledge or
representation you have of a space. The research carried out since
"interactional" or experimental positions rejected the use of this
methodology for considering it descriptive and lacking rigor from the point of view
methodological. However, currently, numerous researchers are returning
to use the verbal descriptions of the subjects as a way to objectify their
spatial representations. Thus, for example, the authors who address psychology
environmental from a transactional perspective (for example, Gauvain and Rogoff, 1989),
they offer us new and promising perspectives to analyze the descriptions with which
the different subjects verbalize their spatial representations.
Therefore, in recent years, a good number of publications have emerged that
they study the spatial representations of sighted children through
verbal descriptions (Gauvain and Rogoff, 1989; Waller, 1985; Waller and Harris, 1988).
Such descriptions are further rigorously analyzed according to the
knowledge stemming from both research on language development
as from the evolution of spatial knowledge. Some of these authors also
they use verbal instruction methods to train children in knowledge of
a specific environment. In general, the results seem to conclude that the techniques
verbal -both for instruction and for the objectification of spatial knowledge
acquired - can be used with children, even at a young age. Of course, both
the terms used by children, such as the structure of the descriptions, are in
function of age. The data seem to indicate that children are capable of using
first temporal descriptions of a space and only later others of a character
spatial. Likewise, the understanding and production of temporal terms and
spatial ones also follow an evolutionary sequence. In the case of the temporal ones, the
children seem to use words such as 'and' or 'then' first, to establish the
links between the elements that make up a route. Only later are they able to
sort those elements following a quantitative order. Regarding the terms
spatial, simple topological relationships (near-far) are understood and used
first, much later the projectives begin to be used correctly as
left-right, and only starting from adolescence cartographic concepts
abstract as north-south.
Since the experimentalist perspective has also dominated the field of study
the environmental knowledge in blind people over the last few years is limited
the researchers who have used verbal descriptions as a method to
externalize the spatial representations of the blind. Some, like Hollyfield and
Foulke (1983) uses the subjects' verbalizations solely as data.
complementary to those provided by other techniques. Others, like Rosencranz and
Suslick
(1976), they resorted to sequential and unidirectional verbal descriptions so that
blind adults learned the placement of a series of furniture in the
space formed by a room. They also assessed the knowledge acquired by
the blind through such procedures using verbal techniques, in this case, a
questionnaire prepared by the researchers that contained eight questions about the
acquired spatial representation. The questions were of the type 'What is it that is at
the right side of the sofa?", "what is the shortest way to get from the table of
telephone to the sofa?... The results obtained showed that both the training
Verbal as the post-questionnaire were good procedures for the blind.
Two of the four trained early blind individuals were able to obtain a
two-dimensional spatial representation of the room from the description
unidirectional that they had received, as well as to communicate it through their responses.
More recently, in 1987, Easton and Bentzen also used verbal procedures.
to try to find out if the spatial representations of the blind had a
iconic or propositional format. For their part, Carreiras and Codina (1991) used, with
good results, verbal techniques to teach blind people about a
environment represented in a model. These data allow us to assume that the use of
of verbal procedures both for instruction and for evaluation of
Spatial knowledge of the blind can be very appropriate. As it was established
manifesto in the chapter dedicated to psychological development, language -and codes
representational with it associated - represent a powerful tool in the
knowledge of the world by
part of the blind. In this sense, Vanetti and Allen, in a study conducted in 1988 with
sighted adults concluded that the accuracy in the verbal description of a space
it was related to the general verbal skills of the subjects. Therefore,
although new work is needed on the capabilities of individuals
blind people to verbally communicate their spatial knowledge, we advise the
researchers the rigorous use of such techniques with both children and adults.

6.4. Relationships between the different methods

Having come this far, we find it necessary to refer to a methodological aspect.

important. It is about analyzing the internal reliability that the different ones have.
procedures for the objectification of spatial representation, as well as the validity of the
same. Talking about reliability in tests that assess spatial representation
it is very complicated, because spatial representations are not stable:
any spatial experience that an individual has can vary the
representation they have of a specific environment. Furthermore, as the reader knows, in a
mental representation can never dissociate the components
locational or geometric (more stable over time), of the attributive or
emotional (much more changeable). Therefore, it is very difficult that, for example, the
representation we have of our
your own city remains constant and unchanging for a long time. For all of this
There are very few studies that have examined internal consistency of
procedures for the objectification of spatial knowledge. On the contrary, it has
dedicated more space in the literature on environmental cognition to the study of validity
convergent that some of these procedures have. Since this is a field
very specific, we will only deal here with validity studies in relation to the
representation in blind subjects; we refer the interested reader to the excellent
reviews of the research with psychics, published by Evans (1980) and Aragonés
(1985).
Few convergent validation studies have been done between the various
procedures for objectifying the spatial representation of blind people. The
The most relevant in this area are those of Rieser, Hill, and Bradfield (1985) and Bradfield.
(1988). In both studies, the data obtained were compared with each other.
different methods of estimating distances and directions. The correlations
obtained ranged between
the values from 0.50 to 0.60 and, as is logical, the highest were obtained when comparing a
same method evaluated with two different measures (e.g. two different systems of
measure for distance estimations or two estimation procedures
addresses).
One of the main objectives we aimed to achieve in our own
research work on the spatial representation capabilities of the
blind people (Huertas, 1989; Huertas and Ochaíta, 1992; Ochaíta, Huertas and Espinosa,
1991), was to compare the different procedures for objectification or communication of the
spatial representation. When comparing the different measurements corresponding to the technique
analytics used - distance estimates analyzed with MDS - with those taken
about the global procedure - reconstruction using a model - we obtained some
very high correlations that ranged from 0.79 to 0.97. This means that both
procedures measure practically the same thing and, consequently, that they can
to be used interchangeably so that the blind can communicate their representations
spatial. When comparing these results with those obtained by Bradfield, Rieser et al.,
It is evident that these authors have obtained notably lower correlations.
These differences between the correlations obtained by us and those of the authors
Americans may be due, in part, to the different methods of objectification of the
spatial representation that were used in one work and another. In the investigations of
Bradfield or Rieser et al. correlated procedures that evaluated each other.
different components of spatial representation, that is, distance estimates
and address estimates. In ours - although it is true that they were compared
procedures as different as distance trials and reconstruction of
space through models - it is also true that the subsequent analyses applied to the
both procedures were very similar. In fact, the multidimensional analysis
convert (as previously explained) the distance estimates
carried out by an individual in a global configuration of a cartographic nature. Once
once that configuration was obtained, we were able to perform the same analyses on it that we
they did in the model: evaluation of reference systems and analysis of
conglomerates. Precisely this can, from our point of view, explain
also the high correlations obtained. The reader interested in delving deeper into these
methodological themes can refer to the works of Huertas (1989) and Huertas and
Ochaíta (1992).

6.5. Spatial behavior

As has been said several times throughout this chapter, spatial behavior, the
mobility that an individual develops in a specific environment is at least partly
determined by the spatial representation that the individual has of that environment.
However, despite the existence of clear relationships between mobility and
representation, even today we do not have consistent data that explains in what
such relationships are consistent. Despite this, most of the authors who in the
The current state of affairs is dedicated to the study of spatial representation, often taking for granted -
more or less explicitly - the existence of relationships between spatial behavior and
representation (Golledge, 1987). Thus, such authors assume that, by observing the
spatial behavior that a subject performs in a certain environment - to which it
it is called a 'behavioral map' - it can be inferred the representation that said subject has
from that environment.
The procedure that is usually used to study spatial behavior consists of
analyze, through more or less structured observations, all behaviors
(both motor and verbal) that a subject performs when moving through a
space. According to Martínez Arias (1987), this type of procedure has a
great ecological validity, but - it is also heavily influenced by strange variables, by
biases
personal and the specific sampling conditions. Despite this, we think
that a good systematic observation system, which has been designed for a
concrete research and, consequently, takes into account the aspects that the
the researcher wants to measure preferably, as well as the biases that could arise
producing is very useful for studying spatial knowledge.
Most of the work that has studied spatial knowledge of the
blind people have provided some data about their actual spatial behavior, precisely
because of the relationships that exist between mobility and representation in the absence of vision
they are stronger. As was made clear in section 3 of this chapter, this
it can be inferred from the fact that when a blind person moves through an environment, the suitability
his spatial behavior is more determined by the spatial schemas he already possesses
-cognitive anticipation- that is due to reduced and fragmented perceptual anticipation that
they provide their sensory systems. Likewise, as we also know, the
observation of spatial behavior is used to evaluate the results obtained with
the different instructional techniques in orientation and mobility used with the blind and
visual impairments.
We will resort, once again, to our own research, to briefly describe the
Read some of the procedures with which mobility or behavior can be measured.
spatial of blind people (Huertas and Ochaíta, 1988; Huertas, 1989; Huertas and
Ochaíta, 1992). One of them consisted of coding and quantifying, through a
systematic observation procedure, the adjusted and maladjusted behaviors that
the subjects performed while moving along a certain route. Four were established
categories of 'mismatch' -stumble, go too far, get lost and deviate- and a single
of normal march. Another procedure consisted of quantifying through a
previously established categorization, the number and type of aid that they need
blind people when they moved through an environment that was not completely
unknown. A third measure referred to as "success in displacement" had
consider both the aid we have just cited and the capacity of individuals to
find a
new route. A final procedure simply consisted of measuring the real time that
was used in the route. The interested reader can find data and explanations
more precise about these procedures in Huertas' work (1989). In any
In this case, the first three aids (adjustment, support, and success) proved adequate for evaluation.
the spatial behavior of the blind. On the contrary, the measure of time was not.
since no relationship was found between learning a route and the time that
it took a long time to cover it. When -as happened in our work- it is not said to the subject that
must travel the route as quickly as possible, the time it takes to do so is
subject to a series of circumstantial, personal, and physical factors that have nothing to do with
see with the knowledge of that route.
Finally, it should be noted that in the frequently cited research, we also studied the
existing correlations between the different measures of spatial behavior and
representation in blind children and adolescents. We found high correlations when
compare with the measures of spatial behavior (excluding the time spent on
the route), with the scores obtained both in the models and in the
distance estimates. The correlations ranged from 0.60 to 0.81. Our data
seem to corroborate Foulke's thesis (1982 and 1985), according to which, in the absence of the
perceptive anticipation that vision provides, blind people have to rely on
its representations, its spatial scheme (cognitive anticipation), in order to
to move through a space with some ease. Consequently, we think, although not
we have data on this, that in sighted people the correlations between the
mobility and representation measures should not be as high as they are in
the blind women.

7. Some implications for the teaching of geography

We do not want to end this chapter without providing the interested reader with some information.
about the implications of the results obtained in the research on the
spatial knowledge they have when teaching geography to blind schoolchildren and
visually impaired. Undoubtedly, it is important for geography teachers.
those in charge of teaching the blind should know things such as the peculiarities
of the development and learning of spatial knowledge in the blind, the
most appropriate procedures to externalize their spatial representations, or
How the ability to handle tactile maps develops. Geographers such as
Catling (1978), Graves (1980 and 1982), Capel, Luis, and Urteaga (1984) and Broadman
(1984), they highlight in their publications the importance it has for the teaching of their
discipline the knowledge of the data provided by developmental psychology of
spatial knowledge.
Graves, in his 1982 book, advises school geography teachers.
psychics who ask themselves a series of questions when starting the instruction of their discipline.
From our point of view, those issues --whose answer is closely
related to the psychology of spatial knowledge - are even more advisable
when the teacher has to teach geography to blind children and adolescents. In
concrete, according to the cited author, there are four questions that one must ask oneself
Professor: 1) Who are the subjects that have to learn the discipline?
What abilities do those students have?
What objective indicators will show the progress?
progress? Next, we summarize the implications that these
issues that may arise for the education of blind and visually impaired students.
When we consider who the students are who will carry out the learning,
we try to analyze the interest and the opportunity that the content to be acquired
they have for them. Without a doubt, this is a decisive question for teachers of the
the visually impaired since they not only have to adapt the materials to the perceptual abilities of
the blind. Also and above all, they must take into account that the lack of vision restricts
the ability to understand space and the cognitive and affective transactions that
They occur among the blind and the environment is very different from that of the others.
psychics. The same happens with the motivations that blind people may have for
learn geography.
The second question suggests that the teacher take into account prior knowledge.
what the students have in the different areas related to the discipline. Thus, it must
to know what the baseline is in which the student is in relation to the
contents of the subject. But it also needs to know the level it has in
general spatial knowledge, as well as their possibilities for collecting and for
objectivize the knowledge acquired in a certain space. For this last point, one can
be useful the information contained in section 5 of this same chapter about the
development of spatial knowledge in blind children and adolescents. However,
it must be taken into account that development cannot be regarded as something unchangeable,
but rather should be understood in a broad, flexible sense and susceptible to being
fostered to the maximum. Precisely the objectives of the educational process must go
aimed at enhancing the capabilities that the student possesses through learning
mentored by the teacher. Therefore, the fact that the level of development of a student
determining in a broad sense their possibilities of understanding space does not imply
that the educator should adopt a passive attitude and teach the student only that which
that already understands. Therefore, the instruction of the blind in geography must be directed
towards their 'zone of proximal development' (Vygotsky, 1934), which means that the
The teacher must direct their teachings precisely towards the immediate levels.
higher than the current development area of the student.
Let us now answer the last two questions: what are the
progress indicators and how their evaluation can be carried out. In our opinion, it is
fundamental that the program is designed in such a way that the concepts and notions
geographical areas are as well-defined as possible and are arranged in
structured and sequenced form. This will make it easy to assess the progressive knowledge
what the student acquires in relation to what they had before the instruction.
It is important for blind schoolchildren to approach the understanding of geography
descriptive in the most direct way possible. In this sense, the instruction must
start with the places closest to the child, those from which they can have
direct experience, such as the class, the school, the neighborhood, and the town or city.
Precisely from these known places, the work can begin.
introduction to cartographic conventions (using models, tactile maps,
verbal descriptions, etc.), as well as in the spatial concepts that the child should
to learn.
Finally, it should be noted that the evaluation must be related to the contents of the
program but also with the characteristics of blindness. Insist again that the
the lack of the visual system creates different ways of relating to space and,
so much, to understand that space. Consequently, it cannot be assumed that the student
blind I came to understand the different concepts involved in the physical geography of the
same way as the sighted student. It is important to keep in mind that many of these
concepts have no direct reference in the absence of vision, and therefore, the
a blind person has to perform a much greater cognitive task than a sighted person to achieve
understand them.

7.1. Tactile maps

One of the biggest problems faced by the geography teacher when trying
to instruct their students, is the difficulty that children and young adolescents have
to conceptualize and read maps. Such difficulties could be summarized in the three
next. First of all, schoolchildren often have trouble understanding that
the map is a representation of reality and therefore, there exists a
correspondence
between the elements of the map and those of the real environment, although in most cases
this may not be an exact correspondence. Secondly, children also have
difficulties in selecting the most relevant information within a
map, since, in most cases, it is not necessary to use all of the
information it contains. Finally, it should be noted that a large part of the
difficulties that children face in using and understanding a map are due to the
inability to self-locate within it, which leads, in most of the
cases, where the map is not oriented correctly (Board, 1978; Blades, 1990).
According to Blaut and Stea (1971), sighted children can start using the...
cartographic information contained in maps since the beginning of the school age,
as long as the map represents geographical areas very familiar to the student and that
it does not involve conventional symbols. Only at the beginning of adolescence, starting from
At the age of 11 or 12, sighted students will begin to understand symbols.
conventional maps as well as the meaning of their scale, so they will be
possible to use the information contained in abstract maps and those referring to places
distant and unknown (Bartz, 1970; Heamos, 1973).
It seems obvious that the difficulties inherent in understanding maps increase in
blind and visually impaired children. As we have mentioned throughout the
pages of this chapter, the experience that a visually impaired person has of the environment is
smaller than that of a seer. Moreover, the act of representing space requires for
the blind man greater intentionality and cognitive effort. On the other hand, understanding
of the spatial relationships represented cartographically in a space
Bidimensional is very difficult to understand through touch. For all of this - and
also because they are used by many blind people as aids for their mobility-
She has dedicated considerable research effort to the study of tactile maps.
The first experience in the design of tactile maps is attributed to Samuel Gridley.
Perkins School for the Blind. Its work culminates in 1837 with the publication of a tactile atlas.
from the United States. In 1937, Clara Pratt publishes her book 'Practical Geography', where
Some effective strategies for teaching geography to children are described.
blind. Specifically, she advocated for a method according to which children
they had to create their own maps using different materials. Subsequently, they.
they have designed a certain number of instruments to teach geography to people
blind and visually impaired. In general, we can say that such instruments have
intended to provide you through touch - and sometimes also through hearing the
spatial information that seers obtain through vision. In relation to
this, it should be taken into account that the mere translation of the visual information contained
on a map, in a tactile format, does not guarantee that the blind person will get the same from it
knowledge that a clairvoyant. As has been widely pointed out in chapter 3 of
in this same book, the perceptual characteristics of the haptic system are very different
to the visuals.
There are a series of requirements that must be taken into account when creating a map.
tactile that is useful and effective for the visually impaired. On one hand, the arrangement of the
The information contained in the map must be suitable for the characteristics of the system.
haptic. Additionally, other more pedagogical requirements must be taken into account -
how the way of placing and exploring the map facilitates learning of the
information contained in maps and, consequently, its use in life
daily. Next we will analyze the incidence that aspects such as the
scale, the amount of information, and the format in the understanding of tactile maps.
The symbols used in tactile maps are of three types: points, which
indicate specific locations or milestones; the lines that designate borders or lines
of demarcation; and the texture symbols, which delimit areas. Furthermore, it is necessary to consider
four factors that influence the discrimination of symbols and, in
consequence, in the readability of the map: the size, the relief, the shape and the orientation.
Regarding size, tactile symbols must be quite larger than the
visual, since touch is a sensory modality that discriminates information
spatial with less precision than vision. The differences in relief are used to
differentiate
between areas and lines. Regarding the shape of the symbols, it should be the most
analogous possible since subjects recognize symbols much more easily than those that
they resemble in some way the elements they represent.
It is also important to keep in mind that the information contained in a map
tactile should be broad and complementary but not redundant. In this sense, the
Isikov's publication (1966) indicated that the information contained in a map was
more accessible for the blind when using symbols with different shapes and
textures. But this is only as long as the number of symbols is not excessive since, in that
case, complicated the understanding of the map. However, other authors have found
that when using quite a few different textures and with low contrast between them, the
understanding of the map is worse. In this sense, Berla and Murr (1976) found that the
the fact of adding different textures to the map symbols made it difficult to their
localization
it increased the time needed for its recognition. These data, which
they can apparently be contradictory, they seem to indicate that when the
the information contained in a tactile map is too extensive, it can generate
difficulties in their reading.

In this regard, James provided a series of recommendations in 1972 to avoid the

problems generated by excessive information contained in a map. For example,
it recommended the use of numbers or letters to replace inscriptions
contained in the map. Such inscriptions, along with the number or letter chosen for
they should appear outside the map.
When the information contained in a map is taken by hand, its
interpretation is different depending on the exploration sequence that is followed. For
Hello, it is important to instruct blind students in exploring the keys of
orientation of the maps. However, the data obtained by Nolan and Morris (1960),
seem to indicate that most students do not use systematic strategies.
to explore a tactile map. According to Beda and Murr (1976 b), it is advisable that
a preliminary mapping trace is carried out to find its orientation. In addition
they claim that better information is obtained from a map when it is explored
vertically using both hands. These authors (Berla, 1973; Berla and Murr, 1974)
they studied the effects of training on map exploration strategies,
concluding that few training sessions were needed to achieve
very positive results. Berla, Butterfield, and Murr (1976) found that the
map reading skills correlated positively with the use of
systematic exploration strategies. They conclude that approximately one hour and
training media provides a gain of between 20% and 40% in both
the speed as in the accuracy of reading the map.
Once the factors that facilitate the understanding of tactile maps are analyzed for
the blind and visually impaired students, we now proceed to study what is the
interpretation they make of the information contained in those maps. Such
interpretation, as analyzed below, depends on both the knowledge that
the students have about the geographical concepts that the map contains, such as of a
series of didactic prerequisites.
Regarding geographic concepts, Berla and Butterfield (1975),
they investigated the use that visually impaired children made of tactile maps
United States and Canada. These authors found that the hardest task for the
children, it was about associating the characteristics of maps with reality. Therefore, they carried out a
initial training program in map study. Such a program would begin
leaving
from the maps of the classroom, the school, the neighborhood, etc., so that the children could
compare the information contained in the map with its real counterpart. The results
they demonstrated the effectiveness of this training program in understanding the
meaning of maps. Therefore, it seems necessary that the complexity of the map and of
physical space that represents, gradually increasing to facilitate its
interpretation by the students.
When we talk about didactic prerequisites, we refer to the content that is
it must be included in the maps. The experiences obtained directly in the school (whose
results match those of the studies that have just been cited), put on
I manifest that children should start using maps that represent environments
known, in order to subsequently transfer the skills thus acquired to the study
and the interpretation of maps corresponding to unknown spaces. In any
case, when blind students have to receive instruction in areas
unfamiliar geographical areas, it is necessary to accompany the information contained in the
map with another that the teacher provided them verbally. It is also advisable
What. To avoid the problems posed by understanding the scale of the map when
represents an unknown environment, the teacher provides some examples that are
refer to family environments for the student, using the same scale. On the other hand,
Partly, the teacher must also teach the students the ideal starting point for
start reading the map, as well as the sequence that must be followed to integrate the
information that contains in the best possible way. In the case of blind schoolchildren and
for visually impaired individuals, it is advisable to restrict the content of the geography curriculum,
and convey to them only the information that is most relevant to them and
essential. In any case, the chosen curricular contents must
contain information regarding physical and political aspects, as well as data that
they refer to the climate, the population, etc...
Once the importance of using tactile maps for has been pointed out
teaching geography to blind and visually impaired schoolchildren, we believe is necessary
pointing out a key issue whenever they are referenced, it is about
the problem of its production. Most of the tactile maps that are used for
The instruction of blind schoolchildren has been developed by their own teachers.
in a particular way. Thus, there are not many standardized materials that are used in
the school for the teaching of geography. However, there are some atlases and globes
terrestrial, which have been carried out in a standardized way to be used by
blind and visually impaired students. Below we present to the reader the aspects
more critical of these materials, as well as certain proposals for their improvement.
First of all, it must be highlighted that materials are scarce.
-tactile maps and atlases- available on the market for use by the
blind students. Moreover, such materials are not always duly
updated. On the other hand, most existing atlases use a scale
too small and an excessively schematic and poorly analogical symbolism, for
what often prevents their users from obtaining a clear picture of the
reality they represent. Finally, it would be necessary to adapt tactile atlases and globes, to
that could be used by students with usable visual remains,
adding colors and written information.
It is also important to take into account the problem posed by the use of
terrestrial globes for the education of the blind and visually impaired, since they
it raises the dilemma of the relationship between the absolute size of the balloon (diameter), and the
amount of usable information it contains. Thus, there are small balloons
size built to be easily handled with the hand and, therefore,
susceptible to being manipulated by small groups of students within the class.
Such balloons can present a small amount of information if it is intended to be good.
structured. It is also possible to increase the diameter of the balloon to introduce more
information and a greater number of details, but this increase in size does
extremely difficult to handle, and poses methodological and didactic problems.
In an attempt to alleviate the problems presented by balloons and tactile atlases, measures have been taken.
presented some alternatives over the last few years. For example, designs have been made
new terrestrial balloons that, following the principles of additive information and
through vacuum thermoforming techniques, they contain several layers that can be removed
overlapping. These layers adhere to each other through a magnetic strip,
which allows them to be moved easily. These balloons are usually accompanied by
a volume written in braille that includes the pertinent explanations. It seems
that blind schoolchildren are able to handle these balloons quite well
suitable. Geography books have also been designed, which include tactile maps, and
that follow the same principle of sequentiality of additive information, since a
the same map may appear sectioned across several pages. We can therefore conclude
that in recent years, considerable effort has been dedicated to the design and
production of teaching materials that facilitate the teaching of geography to the
blind and visually impaired students. In general terms, it is intended that the
maps have a manageable format and, at the same time, include the information
necessary for the student, for which they often gather oral or written information
supplementary. Maps are also being developed to which colors can be added and
labels so that they can be used by students who have some disability
visual.
To conclude this section, I will briefly inform the reader about the development.
of the materials used for tactile maps, as well as the techniques of
production of the same. While the first maps were made with a
material -manila paper- slightly resistant to water and that deteriorated easily, in the
currently there are materials and techniques that are much more appropriate and often
sophisticated. For example, a method used in the preparation of maps consists of
to use
a relief map that represents the outline of the map; over its different areas are
apply a special paint that subsequently, through a reactive process, goes
acquiring different colors according to the temperature. There are also other
less sophisticated procedures, but also quite a bit more economical, such as
thermo-vacuuming at different levels of relief, the use of metal sheets with
different textures and levels of elevation, and even some techniques by which we
they obtain three-dimensional maps. Ultimately, the most important thing -and it seems that the
research efforts are heading in that direction - it is to find production techniques that
coordinate costs appropriately with the quality of the maps.
Chapter 6
READING IN VISUALLY IMPAIRED INDIVIDUALS

ALBERTO ROSA. JUAN ANTONIO HUERTAS y CECILIA SIMÓN

1. Access to cultural information. Reading processes and other substitutes

Writing is a cultural artifact whose everydayness should not obscure its

transcendental influence on the organization of our lives and, consequently,
about our modes of thinking. If the appearance of oral speech as a development
the communication transformed the psychological functions of our ancestors
making possible, among other things, the emergence of mental skills of a type
metacognitive; the invention of graphical ways of recording information has brought
I achieve socially significant changes, in addition to forcing people to
they use this communication tool to carry out certain operations
highly specific psychological tasks of assigning meanings to a
set of graphical representations.
But the psychological consequences of the widespread use of the cultural artifact that is the
writing is not limited solely to the occurrence of those psychological operations
specific related to the tasks included in the reading process, but rather, when changing
the social modes of regulating behavior and transmitting information,
it may have also influenced in a more or less indirect way on the
the way in which other psychological functions are carried out. Let's consider, for example,
the type of mental operations performed by individuals "in a non-literary society in which
The cultural legacy is transmitted orally (for example, through epic poems.
memorized generation after generation); in this case probably the
memory operations would include the use of strategies different from those used in
our culture. Undoubtedly, the implementation of modes of communication and
of learning based on reading and writing presents to the psychic apparatus the implementation in
march of particular action strategies that exceed the mere process of
understanding of the text. Let us think that our cultural memory is gathered
primarily in books and must be sought, incorporated, and enriched through
skills related to literacy.
As a consequence of all this, a person who wants to live integrated in our
society necessarily needs to carry out activities that require reading and writing
and therefore, must master the precise psychological skills to be able to carry out
this task. In fact, the ability to read and write has been considered for quite some years now
as an unavoidable necessity in our culture. The current educational systems
They propose as the primary objective to achieve these skills which, in turn, act as
key for subsequent academic progress. Ultimately, the mastery of literacy.
it facilitates access to cultural memory and integration into the social body.
Much has been written about the cognitive effects that literacy produces. Scribner
and Cole (1981) have examined this issue in detail through a study in which
the performance of subjects who mastered different types of systems was compared
reading-writing used for different activities within the same scope
cultural. Their results lead them to assert that each system of written notation
involves the use of highly specific psychological operations, and that the transfer
Whether these acquired skills can be applied to other types of tasks largely depends not only on
of the degree of similarity of these tasks with some of those included in the act of reading,
but also with the social use made of each type of reading, which provides a
specific training in carrying out certain tasks. The mastery of the
literacy does not imply by itself an important restructuring in the
operating mode of the cognitive apparatus, but rather, the addition of a new
repertoire of skills. However, it is the area of activities that enables the
mastery of literacy does produce significant changes in the
psychological functioning. The type of tasks that are carried out in school, which
they imply insistence on the use of clearly specified rules for the
generalization of skills or the use of a progressively growing language
decontextualized and abstract, and favored by the use of written language,
would be responsible for the differences in cognitive functioning that the
transcultural research has observed among literate subjects and
illiterates (Rogoff, 1981; Scribner and Cole, 1981).
Therefore, although literacy in itself does not seem to produce changes
transcendental in the development of the subject, does indeed enable the fulfillment of
activities whose consequences will be of great importance. In any case
It is also important to consider that those school activities and the incorporation of the
cultural memory recorded in writing does not have to depend exclusively on the
direct reading of the subject. The reading aloud by other people, or the
auditions of magnetic tapes can play an important role when it comes to
broaden a person's knowledge base.
From what has just been exposed, it follows, in our opinion, that literacy is
a communication tool for carrying out activities with meaning
social. In order for these activities to be carried out, it is necessary that they are previously
they have acquired a set of specific literacy skills linked to the type
of notation that is used. There are different types of writing (for example,
ideographic, syllabic or alphabetic) and each of them forces to perform certain
psychological operations of a different nature. This is not the place to explore these
differences, however it is indeed relevant to mention them since in the case of
For the visually impaired, access to written information presents some difficulties.
differential characteristics. Normally, notation systems of writing have
were built for use by subjects not affected by any deficiencies and
they rest on visual perception, and in the case of alphabetic writing, they relate
sounds with graphic characters. When vision is affected, the physical configuration of the
written characters and the way of perceiving them must necessarily be different from the
common for psychics. This makes the reading process they perform...
subjects have some peculiarities compared to those of the seers of their own culture.
This chapter is dedicated to examining the form that the reading process takes in the
case of individuals with visual impairments. To do this, we will start by describing
the reading and writing systems used by individuals with severe visual impairments,
focusing especially on the braille system. Afterwards, we will examine with some
detail the psychological operations included in tactile reading activity in this
system. And, finally, we will refer to the teaching of reading skills in the
blind.

2. Reading systems for the blind

2.1. Brief historical overview

The act of reading by people with visual difficulties presents a
obvious problem in its initial phases, that of collecting graphic information
business. In cases where the visual disorder is not very significant, this problem
It can be done through various procedures (lenses or using larger font size
to the normal fundamentally), but when the residual vision is very poor or nonexistent
we must resort to writing notation systems that do not require vision.- The way
tactile has been the most obvious candidate to access written information, but this has
needed the development of particular adaptations of the notation systems.
Let's take a brief tour of the history of these adaptations.
The first news we have about a reading system for the blind was the attempt
from Spanish Francisco Lucas who in 1580 constructed texts using letters
of the Roman alphabet engraved on wooden tablets. An interesting idea, but that without
The embargo soon fell into oblivion, it was the one developed in mid-
18th century by Vionville, a blind musician. Instead of opting for the use of characters in
relief on a flat surface designed an alphabet based on different knots
sizes made on a string (Smith, 1929).
In the 19th century, different innovations appear that will eventually lead to the
systems we know today and that are surely closely related to the vast
development of public education and attention to individuals with deficiencies that
followed the French Revolution. Valentin Haüy (1745-1822) is a character who
he plays a very important role in this story, he was the creator of the first school
special for the blind in Paris and, moreover, the first to systematically teach the
reading and writing using cardboard cards on which the letters are
they presented in
relief and that allowed, once arranged on a frame, to write words and phrases.
Although this system even made it possible to build books, it does not appear to have been in use.
easy, because when Louis Braille entered this school in 1819 there were only
14 books of this type that were used very little (Barnett, 1980).
England was also the cradle of developments in this field. The first attempt was that of
Alston in 1827, with characteristics very similar to those of Haüy. In 1837 it appeared in
Bristol the Lucas system based on combinations of stripes, curves, and circles that
they remember Pitman's shorthand. Neither of these two systems managed to achieve a
really important dissemination. The case was different for the system developed by
William Moon (1818-1894) in 1845. This system used grouped lines in a way
that the letters thus constructed are like a stylized version of the capital letters
from the Roman alphabet, something that represented an advantage for its use by
people who had lost their sight after already knowing how to read. A characteristic
interesting about this notation system is the use it made of the
return movements of the reading finger, as the lines are written from left to right
were interspersed with those written from right to left, with the characters in this
second case presented in mirror with respect to the first. The Moon system shifted in
Great Britain to the two mentioned above and has survived to this day (Barnet,
1980), and there are still those who argue that the approach on which it is based
it has advantages over Braille
(Thurlow, 1988).
J.W. Klein's contribution has the merit of marking the transition of the
relief line systems to point systems, although it was limited to replacing the
profile of the uppercase letters by a line of dots. Despite this change
It apparently turned out to be effective for teaching.
The immediate antecedent of the Braille system has its origins in something very far from the
concerns about education. An officer of the French army, Charles Barbier (1767-
1861), designed an alphabet based on point configurations to be read at night
in the battlefield without the need to reveal one's position by lighting a fire;
this system was called 'night writing'. Its design was based on the idea that the
angular letters were easy to recognize by touch, so I stylized them based on
reduce them to the points that marked the vertices, as many letters resulted
confusingly completed them with configurations of points situated arbitrarily within
a matrix formed by twelve points. Later, he adapted his alphabet for its use.
for the blind under the name of 'sonography', being then introduced
experimentally at the school founded by Haüy, being this the way that Louis
Braille came to know him.
Louis Braille (1809-1852) was a student at the school for the blind in Paris who later
would become a teacher at that same center. Concerned about the difficulty of the different
reading systems, and also due to the almost impossibility of the blind to write
Based on them, it was decided to work on the basis of the Barbier system. Initially,
moment reduced the cell from twelve to eight points to, starting in 1824, reach the
configuration of six points that we know today, and in which he managed to represent all the
letters, numbers, and musical symbols. In 1829, he published a first version and another, more
elaborated, in 1839. However, its reception was limited. Its own school did not
adopted until 1859 and its use did not cross French borders until much later.
Subsequently, other point systems were developed independently.
In the 1860s, William B. Wait designed an alphabet known as 'New York'
Point System" whose arrangement of the points was very different from that of Braille, since in
place to work based on a matrix of points with a normalized dimension,
he followed the philosophy of making configurations as simple as possible for the letters more
used and adding the points that were necessary until occupying two rows
horizontal. This predominantly horizontal spatial arrangement was revealed as
less effective than the vertical of Braille. A decade later Joel W. Smith, a
blind maestro from Boston, created an adaptation of Braille known as Braille
American. These systems remained in use until the original Braille system
It was adopted in the United States in 1916. In 1936, the English and Americans unified.
its braille notation.
Currently, there is a Spanish version of Braille standardized for everyone.
Spanish-speaking countries. Moreover, based on the Braille cell, they are represented not
only the letters of the Roman alphabet, but no punctuation marks, numbers, signs
mathematics, musical notation or letters from other alphabets. In addition, there are systems
abbreviations of writing that represent common configurations with a single sign
letters within a language ("stenography" in Spanish, or "braille type 2" in English).
The current technological development has enabled the creation of devices that allow for the
blind people access to printed text. The "optacon" is a device equipped with a pen.
optical that located above a letter, and after passing through a transducer, sends a signal to a
grid of dots over which the braille representation of that letter appears in relief,
what allows it to be perceived tactilely. In this way, and through the
sliding the optical pen over a line, a blind person can read printed text
normal. However, reading manuscripts is practically impossible because of this
procedure.
Surprisingly, the development of materials for the utilization of waste
visual representations of people with severe vision impairments are later in time than the
development of the alphabets for the blind that we just referred to. This can
having to do with the widely held belief until the 1960s that
it was advisable to preserve the remaining vision by saving its use instead of trying to
increase its efficiency, something we already referred to in a previous chapter. Two have
the most commonly used procedures. The first historically was the preparation of
books and teaching materials with enlarged print or graphics
of which standardized use was already reported in 1913 (Coro and Ryser, 1989).
Later,
And in the 1960s, optical aids known as were beginning to be used in schools.
long before, such as magnifying glasses or telescopes, whether with fixed supports,
manuals or mounted on glasses. Recently, even circuit systems are used.
television closed-circuit that allows to increase the size of presentations.
There is another recent system for accessing written information that, although it is hardly...
it can be considered within a reading chapter, we cannot fail to mention here,
we are referring to what is known in Spain as the 'spoken book'. It is about a
technological expansion of the old system of one person reading to another. The substitute
the present reader is a magnetic tape whose speed can be manipulated without
that the tone of the voice is affected. The use of this device allows overcoming one of the
major drawbacks of braille, the slow reading speed.
There are some studies that have empirically explored the possibilities that this
system offers. Tuttle (1974) compared the level of understanding reached by 104
American blind people between 14 and 21 years old in front of texts presented in three modalities:
tactile braille, normal speed hearing, and increased speed hearing. Their
Results indicate that at the same level of understanding, braille reading takes twice as long.
in time than normal speed listening, and three times more than listening to
increased speed, although there is a large dispersion in the results. In any
In this case, it should be noted that for an average subject from their sample, a good speed of
compressed speed audition was 275 words per minute. A very fast speed
considerable for a blind person and contrasts with the reading speed data in braille
which will be presented later. In relation to this, it should be noted that Foulke
(1964) found that the capacity to understand compressed speech in the blind
was higher than that of the seers, while Hartlage (1963) found no differences
appreciable differences between blind and sighted individuals in auditory comprehension at normal speed. These
Foulke attributed the results to the greater training of the blind in this type of task.
These data that we just discussed provide some basis for those who suggest the
exploration of non-tactile alternatives for access to literature by
the blind.

2.2. The Braille system

2.2.1. Description of the characters

This literacy system is by far the most widespread among the blind and to which
Let's dedicate an important part of this chapter. Let's start by describing it.
The braille alphabet is made up of combinations of raised dots arranged in a
vertical matrix 3x2. The number of possible combinations is 63, which exceeds the
number of letters in the alphabet. This allows for dedicated configurations to
to denote punctuation marks, prefixes that indicate that the following signs are
uppercase numbers or letters, and even combinations of frequent letters in a
determined language, as we mentioned earlier when referring to shorthand or
in braille type 2. Figure 6.1 includes the list of braille signs in Spanish.
The normalized size of each braille dot ranges from 0.381 to 0.508 mm.
distant from each other 2.28 mm when they belong to the same cell. The distance
The horizontal spacing between cells is 6.35 rom, and the vertical spacing between lines is 10.16 rom. These
sizes and distances seem to be very close to optimal from the point of view
psychophysical, as various studies have confirmed for quite some time now
(Uniform Type Committee, 1913; Latimer, 1920; Meyers and Ethington, 1956; Calving and
Clark, 1958).
This size, which is appropriate for the sensory characteristics of the yolk
finger, however it is quite larger than that of printed type, which makes
that approximately 1/7 of the text of a regular page fits on each page of braille text
normal business. If we add the fact that the size and thickness of the sheets is
much superior to that of standard paper for ink writing, we find that
A book written in braille has a weight and volume much greater than its equivalent.
in ink. There are two types of surfaces on which braille texts usually appear:
a kind of thin cardboard that can be manually or machine perforated, or a
a type of plastic called 'thermophone' in which the points protrude due to application of
heat and that is widely used for reprographic systems equivalent to photocopying or
the multicopy in ink texts. A particular characteristic of Braille is that the quality
the text eventually deteriorates with use, as the pressure of the fingers while reading ends up
decreasing the relief of the points.

FIGURE 6.1. Braille Alphabet

2.2.2. How to write in braille

Writing can be done in two ways, manually or using a keyboard.

whether mechanical, electronic, or computer-based. Any of these forms of
writing shares a characteristic that distinguishes it from that done with ink: the
impossibility of carrying out a perceptual tracking of the written text. Let's stop
briefly in a description of each of these forms of writing.
Handwriting is carried out using the 'guideline'. This consists of a
a kind of frame in which the cardboard sheet is inserted in order to fix it; on
This frame has a strip placed on it with one or more rows of Braille cells.
writing is then done from right to left by pressing with a stylus on the
points corresponding to the letters that one wishes to write. Note that the writing is
then do it in mirror with each character rotated 180 degrees and
in reverse order relative to its reading position. A quick glance at the braille alphabet
it allows observing the possibility of confusions between letters when performing one or the other
operation.
All non-manual writing systems use the same type of keyboard with seven
records, one for each point of the cell, and another that acts as a spacer. The
typewriters (often referred to as 'Perkins' by the brand of
more widespread manufacturing) have a carriage similar to that of a typewriter
normal on which the card is inserted for writing. To be able to read the text,
that in this case appears from left to right, the subject must move the hand to the
the back part of the car. The precise force needed to operate a mechanical keyboard is a
problem for younger children; this problem disappears with the use of
electronic keyboards that require much less effort. Electronic keyboards
these types are also used as computer peripherals, although they also
It is common for some programs to allow certain keys on the keyboard
"qwerty" standard performs the functions of a braille keyboard.
In any case, it must be taken into account that the blind person cannot perceive when writing.
immediate form the text it produces, for this it must stop the process of
writing and sliding the hands over the text to be able to read, which sometimes implies
even disassemble a relatively complex device in its handling such as is the
agenda.

2.2.3. Touch and Braille reading.

It is advisable for us to stop and analyze the relationships that may exist within the system.
of Braille literacy and the sensory system on which it is based: touch. But
first, let's clarify, in a very succinct way for now, the manner in which
Physically, a blind person explores a text in braille. This is done by sliding.
gently from left to right the index finger over the lines of text. The use of
one of the two hands and the movements they make are related to the
reading proficiency level, and they will be the subject of a detailed exposition later on.
As indicated in chapter 3, no work has been found on
psychophysical aspects of touch a significant decrease in sensory thresholds
in blind people in relation to sighted people. There is also no evidence whatsoever.
that relates the degree of tactile sensitivity and the ability in Braille reading. To sight
From these results, it does not seem that blind people have any advantage.
sensory
compared to those who have visual residuals when learning this literacy system
tactile. In any case, someone might think that the blind would eventually reach with
time is a skill superior to that of seers in gathering information with the
touch, which could generalize facilitating to some extent the speed and the
effectiveness in reading braille. However, this also does not seem to be the case, at least
from the data provided by the literature. For example, when there has been an attempt
find the relationship between the speed of reading braille and skill
stereognosis (the ability to recognize the shape of objects by touch) has been
found correlations close to zero. On the other hand, the research group of
Newman and his collaborators (1984) have been carrying out a whole series of works
that, among other aspects, were trying to compare the ability to estimate the points that
they constitute the different braille letters. To do this, they compared the performance of subjects
seers and blind people, both with little knowledge of Braille, in a task of
discrimination of point configurations that could be explored in a limited time
(milliseconds per letter).
In all cases, the results were similar, as blind and sighted people
they produced a similar percentage of errors when recognizing braille configurations
used as stimuli. Curiously, the percentage of correct answers in these judgments for
the two groups was surprisingly low, only 50%. Also the two groups
they showed
the same types of mistakes, and likewise, as skill increased with the
braille reduced the number of errors made, both for the blind and for the
seers. In short, it seems that the processes that are initiated in the collection
and recognition of written information in Braille are similar in people
blind and those that are not, the differences we may find between some and
others will be fundamentally determined more by experience and skill in the
use of one's own reading and writing system due to supposed perceptual differences.
One question that could be raised is what is the usual capacity of the fingers.
not used for reading (i.e., all except the index) to carry out the reading of
Braille characters. Some work was dedicated to answering this question.
mid-1960s. Foulke (1982) reports a set of experiments in the
that the subjects had to read Braille characters. with different fingers, measuring the time
employee in doing it and the mistakes made. The results indicated that for both
hands, reading ability decreases rapidly in progression from the index finger
the little finger; in any case, even the little finger still possesses a capacity of
tactile recognition that can be useful in reading braille. It is likely that these
differences in recognition capacity are mainly due to a combination
of different causes among which the following may be included: a lower density in
tactile innervations on the stimulated skin surface of each finger, and on the
representation of these surfaces in the cortex; differences in perceptual learning
of some fingers, some previously very trained -in performing tasks in front of others
that are hardly used; and finally to the obvious physical problems so that some
the fingers can be positioned comfortably and effectively to perform the task of
reading

2.2.4. Some advantages and limitations of the braille system

There is no doubt that today the Braille system is the main means of access to the
information printed by the blind. The efforts that have been made
for several decades to unify its notation for each language, its definitive
incorporation into teaching, the institutional support available, and the innovations
technologies that have emerged in the support procedures of this system, it
they become the universal vehicle for the reading of the blind. This character of
the universality and primacy of Braille is truly its main advantage. Thus,
the other procedures for access to communication such as optation, recordings
magnetophones, the spoken book, etc., become mere procedures
complementary to the Braille system.
As a consequence of this relevance of Braille, all technological advances that are
they are developing, especially from the computer field, they are incorporating
valid adaptations for this reading and writing system. Perhaps one of the reasons for
the Braille method hardly finds competitors among the remaining systems.
for the breadth of functions it serves as a printed procedure similar to the
remaining in visionaries. The writings in Braille practically satisfy the same
needs that printed ink writings are relatively manageable and
durable, allow for immediate access for reading without the need for a device
Some enable processes of search, review, and revision, etc. Functions that do not
fully satisfy, for example, the communication procedures through listening
stereo.
All we just said does not prevent us from forgetting the
disadvantages that this reading and writing system still suffers from. Some of
they are related to the sensory system responsible for gathering information
of Braille: touch. Throughout this book we have been able to understand the limitations of
touch, for example, the necessary sequentiality and slowness in the collection of the
information in reading (necessarily letter by letter), the reduced perceptual field
that encompasses the small tip of the finger, or even the fact that braille texts
"wear out" with use, since the points lose relief when they have suffered.
repeatedly the pressure of the fingers. On the other hand, and due to causes that more
we will examine, the reading speed that is generally achieved is very slow
if we compare it to what psychics can achieve in visual reading.
Other difficulties that are commonly attributed to this reading system entail
reference to aspects of the material support of the system. The dimensions of the cells
determines the fact that letters and words have a very size and length
superior to those printed in ink, which makes the texts written in braille be
bulky, heavy, and difficult to handle.
On the other hand, the possible number of combinations of points within the cell
braille is very limited, so it is necessary to frequently resort to a
same arrangement to designate a letter and a number; to the uppercase and to the
lowercase, etc. Nor, in this same sense, does braille provide the same
facilities that writing in ink provides for recording graphs and figures on a sheet
of text. In addition to these intrinsic limitations, braille, due to the specificity of its
code has the added difficulty of being a different notation system, which
hinders the important direct printed communication with the entire enormous world of the
written information for psychics. It is true that lately certain advances in the
computing (printers, bimodal computers -braille and ink-, etc.) are starting
to enable the necessary intercommunication of written products for the blind with the
world of information from psychics.
Ultimately, the set of these drawbacks does not diminish the importance of this method.
, which, for example, the "American Council for the Blind" still
considered critically important for the development, progress, and participation of the blind in
the educational, work, and cultural world in which it must be immersed (Stephens,
1989). Now, it should be considered that these inconveniences make it the
practice in a reading system that is more uncomfortable, slow, and laborious than that of sighted individuals
and that, therefore, still needs some development for its use to be a reality
more frequent than it is today.

2.2.5. What is the effective use of the Braille system by the blind?

A question that is relevant in relation to what we have just discussed is

what is the real degree of mastery of literacy and effective use that
Braille is truly used within the blind community. We are going to try to
to answer these questions as much as possible referring to data from
two surveys, one Spanish and the other American. When it comes to interpreting these
results we must draw attention to the fact that surveys collect the
estimates that individuals make about themselves, which often do not coincide
with their use or with the actual mastery of these skills. To try to overlook this
problem later we will refer to empirical data collected from tests
performance. First, let's take a look at the information we have about some of the
work done in Spain.
Within the data provided by Alvira (1988) about the members of the O.N.C.E.
It is interesting to point out that 22% of the subjects that made up their sample are
capable of reading printed texts in ink, of which 14% required the use of
some optical help. There is no evidence in this study regarding the type of texts or of
optical aids used. Tables 6.1 and 6.2 collect data on knowledge and
use of Braille in Spain.

TABLE 6.1. Knowledge and use of Braille in Spain stratified by age and
sex
Source: Alvira 1988, p. 95

TABLE 6.2. Knowledge of the Braille system in Spain by age (%).

Source: Alvira 1988, p. 96

In a later study conducted by Martínez Garrido (1990), a ...

questionnaire to gather information about knowledge and use of the braille system
by the visually impaired and blind members of the O.N.C.E. Just as in the
Alvira's work (1988), a high percentage (36%) of those who responded to the
survey, they had visual residual and read, with optical aids, normal characters in ink.
In relation to the knowledge that the respondents claimed to have about braille, a
14.2% of men and 20.4% of women are unaware of it, with only 13%
those who claim to know him well.
Regarding the use of braille, 15.6% of men and 22% of women
It states that it is used on some occasions, and only 14.5% use it regularly.
Regarding the work carried out in North America, we will highlight that of Mack (1984).
This study is based on a telephone survey of 30 American blind adults
they had received their school instruction in braille, and of which only two
they were doing paid work. About 97% of these individuals used braille to
write phone numbers or short notes, 3% used it to write letters
personal, compared to 53% who used a normal typewriter with ink or a
17% that resorted to tape recordings. As for reading with
fines
cultural or leisure activities, it was found that 50% resorted to recordings, while
13% never engaged in this type of reading. As for reading for reasons of
work or necessity, 20% claimed to use braille, 6% used optacon, a
17% used magnetic tapes, the same amount resorted to psychics to read for them.
out loud and 40% did not read this type of information at all. In short, the actual use
the subjects of this study did with braille is extremely limited. Although
these data must be interpreted with care given the restricted nature of the sample and the
procedure used.
From the results obtained in both the Spanish and American studies, it
it can be deduced that in the visually impaired and blind population there is a very low percentage of
people who use Braille and it seems that there is a lack of interest in this system of
reading. Evidently, if we consider that reading is one of the methods most
suitable for the cultural education of individuals, the results we have just presented lead us to
lead us to consider this fact as a serious problem in integration and
training of the visually impaired and blind. But what are the causes of this
indifference towards the knowledge and use of braille?
Rex (1989) has attempted to elucidate the factors that may determine the low usage that
Blind people use the Braille system. According to this author, an important factor is
the fact that within the population of people considered to be blind, there
they also find those that present other associated handicaps, which sometimes
they hinder or make it difficult to use braille effectively. Moreover, currently,
people with visual impairments tend to use other materials, both for writing
(keyboards) like for reading (auditory media). On the other hand, it is important to keep in mind,
according to the author, the limitations and difficulties that the braille system itself entails
(readability, errors, volume of texts, etc.) can lead to the emergence of
negative attitudes towards learning and/or using Braille as a reading system. This
combined with the scarcity of Braille materials, especially for university students, makes
that these people prefer the use of other means. To all of this, we would add
we, it is joined by the use of a notation system different from that of the population
general acts as a certain factor of marginalization, as its actual use is restricted in
most cases, to communication among the blind, but not between them and the
psychics. Perhaps the use of new technologies will change this state of affairs.

2.2.6. Some attempts to improve the Braille system

As we have mentioned before, one of the fundamental drawbacks that suffers

the braille system is the slowness of its reading, mainly caused by the need
to read with the tip of the finger a character or a cell each time. With the aim of
increase reading speed and reduce text size, from very early on
In the history of Braille, adaptations of the system appeared that included in a
same cell the information corresponding to one or more syllables, instead of just one
letter by letter. As we know, this is the foundation of American grade 2 braille or
from Spanish shorthand, where certain configurations of dots represent
endings, prefixes, conjunctions or even very common words in a
determined language.
Other ways that have been used to alleviate the slowness of this system have been directed towards
look for other alternatives that do not alter the essential character of Braille, that is,
maintain the model of a cell with a certain number of columns and rows of
points of relief. Since the sequentiality of reading is intrinsic to the system,
the simplest way to expand the communicative possibilities of each cell is
increasing the possibilities of generating point configurations in them.
Foulke (1970) and Foulke and collaborators (1968, 1973) have conducted different
experiments for this purpose, where the number of rows and columns was varied of
the braille cells, successively from 3 to 6 rows or columns, measuring the time of
reading latency. The results showed that for cells formed with more than
4 rows and columns the response latency was too long. Instead, with
cells with 4 rows and columns the latency was lower. It could be deduced from these works
that the size and complexity of the Braille cell can be extended up to a maximum
of 4 rows and columns without varying
the possibilities of recognition, which would undoubtedly mean a geometric increase
in the communicative possibilities of each character. However, today the only
innovation that has emerged in this regard refers to the increase in certain peripherals
from the number of rows of the Braille cell on the computer; the size of the cells in
Many of the so-called 'Braille lines' are usually 4 rows by 2 columns, but without
embargo, the actual use that is being made of this increase is very scarce for now
possibilities.
However, although it is undeniable that the increase in the number of points increases
the number of characters that could be constructed, avoiding the possibility of a certain type
It is no less true that some of the reiterations could worsen.
problems that Braille is already suffering from. As we will have the opportunity to examine with
detail later, empirical research has shown that the lyrics
with
many points, or with spatially complicated configurations, are especially
difficult to recognize, leading to frequent reading errors. These findings
Empirical studies cast a shadow of doubt on the possibility of improving the Braille system.
by this means. In any case, we postpone the examination of this issue to a discussion.
which we will carry out later in this same chapter.
3. The reading processes in the braille system

3.1. Reading activity and psychological processes

The tactile reading of the braille system involves, just like reading for people
seers, the realization of a complex set of cognitive operations. This
this section is dedicated to exposing, without intending to make a thorough review of it
topic, what are the processes that take place in reading in an alphabetical system.
Our intention is to take a brief tour of the processes that occur in the
visual reading to then move on to our main objective which is to study in
detail the peculiarities that arise in the tactile reading of braille (for a
more detailed information about the reading processes in sighted individuals see Crowder, 1985,
Mitchell, 1983, Rayner and Pollatsek, 1989 and De Vega, Carreiras, Gutiérrez-Calvo and
Alonso-Quecut and, 1990, Balota, Flores D'Arcais and Rayner, 1990.
At this moment, you, our reader, are undergoing a complex process with
multiple components, some of which are automated and carried out
quickly and mechanically, while others require conscious elaboration.
Furthermore, the reader will remember that to achieve their current level of reading skill, they had
that previously acquiring a series of skills, thanks to a learning process that
It was more or less long. Precisely, we will focus on these two aspects.
interrelated: reading as an activity that requires the implementation of a
set
complex of cognitive processes, and reading as a set of skills resulting from
a long training process.
In relation to the first aspect, I encourage the reader to analyze what they do when they want
reading a printed text. First of all, it is easy to deduce that a certain process takes place.
visual perceptive on which other mental processes can influence and/or follow, which
conventionally referred to as superiors and which ultimately lead to the
understanding of the message contained in said text.
Let's stop to analyze the behavior, presumably more peripheral, that is carried out in
when we are reading a text, that is, the movement of our eyes while
go through the sentences of a text. If we observe the eye movements that it makes
a person in their reading, we will be able to verify that they move from left to
right with quick shakes, these movements have been called 'movements
saccadic oculars." These movements occur between successive periods in which
the eyes focus on a point. These periods when our eyes stop during
A period of time over a segment of the text is called 'fixations'. The
Information from the text is mostly acquired during stable fixations that in
a good reader lasts normally a quarter of a second, which, without considering the
regressive movements, nor the time spent on the movement itself, would give us a
average of 4 visual fixations per second. As readers
they develop their reading skills, the number of fixations they make varies, in a way
those who are starting to read make three fixations per second while those who
good readers, as we saw earlier, they make four. In addition, both the time and the
the number of words captured per fixation varies as these skills increase
readers. Specifically, children who start reading capture in one fixation 0.55
words, while skilled readers capture 1.33 words in each fixation (see
Taylor, Franckenphol and Pettee, 1960.
On the other hand, as Just and Carpenter (1980) pointed out, readers make greater
pauses in their eye movements at the most significant points of the text (by
example, in uncommon or new words, in the words they mention for
first time a new content, at the end of the sentences or paragraphs to eliminate
inconsistencies, or to construct meaning, or in order to check inferences, or
to integrate ideas or data from different sources, etc.). In addition, the movement of the
eyes during reading is also influenced by factors related to aspects
physical features of the text such as the spaces between words, the number of syllables, and the length of
the sentence. In this way, the higher processes, such as the knowledge of
language or prior knowledge on the subject of the text interact with processes
more basic ones related to the physical properties of the text, in such a way that they exercise
a control over the movement and pauses of the eyes.
But eye movements are just the beginning, after them comes the interpretation of
the written. If we had to make a very general differentiation of the processes that
they occur in our reading, we could classify them into processes of access to the lexicon and
comprehension processes. In any case, it is not possible to make a precise distinction
among others, since to understand something written it is necessary for it to be produced
previously a process of perceptual and lexical access to the written text. In any case,
to facilitate the description of the entire general reading process, we will differentiate
these two large blocks of processes: first we will talk about access processes
lexicon and then we will see the processes of comprehension.
Accessing the lexicon is the psychological process that allows for the identification and/or access to
meaning of the words stored in our memory. For this, it is necessary that
a decoding of the written signs occurs, that is, it is necessary for the reader
recognize each of the letters that make up a word. Now, it is advisable to do
a clear distinction between what is mere decoding, and what is access to
lexicon. A reader can decode both real words and words that do not exist or
that are unknown to them, however, access to the lexicon, in strict terms, occurs
only when a word that is previously recognized is found in our
memory store with a specific meaning. To access a word
stored in our memory from the perception of the printed signs the
the reader can generally use two ways (we do not include in this discussion the path
by which some pre-readers can identify the configuration of a word), a
direct route and another indirect (Morton, 1980; Morton and Patterson, 1980; Coltheart, 1978;
Seidenberg, 1985; Perfetti, 1985). The use of one or the other will depend on aspects
like the level of reading proficiency, the context (for example, knowledge about the
themes covered in the text, the type of task the subject must perform, etc.), and the
characteristics of words (familiarity, readability, regularity).
If when we are driving a car we come across a red traffic light,
immediately we know that we must stop, we do not need to go through a process of
conscious analysis of the meaning of the signal. Something similar happens to us when we
we find a word written as STOP, we recognize the word as a
global entity, in the same way that we recognize a number or the meaning of
red traffic light. These ways of identifying known words are called 'access
directly to the lexicon" or "through orthography." This route does not require that a
intermediate phonological translation between the perception of the word and its identification.
On the other hand, if we come across the word 'fiduciary', to read it probably
we must create a phonological representation of the word from its representation
orthographic, and use it to access the lexicon. In this case, we must begin to
analyze the word into segments to which we attribute a phonological value and not a
meaning as in the previous case. The phonological segments will be assembled
to obtain a "pronounced" version of the written word. This form of
representation gives rise to the identification of the word. This procedure of accessing
Lexicon is called 'phonological or indirect' because there is an intermediate stage.
(phonological representation) between the perception of written signs and the obtaining of
meaning of the word. With practice in reading, these processes come to
to be automated, that is, they are performed quickly and without voluntary control.
As a result of access to the lexicon, the reader finds the meaning in their memory.
from the word (semantic encoding). When talking about access processes to
lexicon is necessary to point out the influence of other processes considered to be of a more
superior. In particular, it is important to consider that the context provides the reader
indications about the possible words that appear in that text. The reader, on the other hand
part, even when not aware of it, uses their implicit grammatical knowledge
in the reading of texts. So that if you read the article 'the', it is immediately activated
expectation that the next word will not be 'truck', but a feminine noun.
This influence of the context can manifest itself in different ways, in the situations
more diverse and/or based on the physical conditions of the material being read. In
Perfecti and Roth (1981) conducted an experiment in which the quality was reduced.
from the reading material. To do this, they degraded the readability of the words with a
gradation from more to less blurry. In their study, the subjects had to read and pronounce
each word in two different situations, either in isolation or in the context of
a correctly structured story. The results showed that in all types
of degradation employees, readers correctly recognized a greater proportion
of words when they appeared within the context of a story that when they appeared
like isolated words. Another study that can exemplify the effects of context in
the reading is the one carried out by Kolers (1970). This author presented to a group of readers
texts in which words with different errors appeared (for example, words with
inverted letters). He observed that the subjects tended to replace the words that
they contained errors due to words that generally belonged to the same class
grammatical than the original word. That is to say, the readers used the information
Contextual to identify the words with errors.
It is easy to see how the situations that these and other authors have studied
experimental forms occur with some frequency in our reading. If the reader
reflect on the process you have gone through when faced with a difficult text
legible (a photocopy with blurry letters, a deteriorated, wrinkled, or wet paper,
etc.), you will find that you have had to resort to more elaborate or comprehensive processes.
to extract the meaning of defective words. Let's see this with an example
simple and very common. Let's suppose that in a text we come across a sentence
Maria drank a glass of water
"cold." To decipher what word is missing, we can make use of two types of
sources of information: one is provided by our own knowledge, that is to say,
we know that the only thing María can drink is a liquid substance, but not
we know what type of liquid it could be. To find this out we would need
resort to an analysis of the discernible traits of the word (it is a word with few
letters, with curved traits at the beginning and end and one vertical in second place), this
information will allow us to eliminate multiple candidate words such as
example, milk, lemonade, soda..., so that when we finish our analysis we can
to indicate with the greatest certainty (as our reader will have quickly found out) that
the blurry word is 'water'.
This is a mere example of the interactions that occur in our reading. The
The first type of information we mentioned in the previous example refers to
high-level processes, more associated with what is understood as text comprehension
elaboration of inferences, extraction of propositions, integration of propositions
in schemes, the use of goals in reading), and that needs the complement of a
second type of source of information to decipher the message, that which refers to
low-level processes, more related to decoding aspects
(letter recognition, syllabic construction, word encoding).
Next, we will delve deeper into the second major reading process mentioned,
comprehension, which is what leads us to the ultimate goal of reading, which is to access
fully to the information contained in a text. We cannot fully identify
the understanding of a written message with that of an oral message, since in the message
There are a series of indications such as gestures or intonation that are absent in the
written message, and which can clarify or nuance the emitted message. In any case
there is still a significant relationship between both forms of communication, since
that, ultimately, both the understanding of a written message and the understanding of
an oral message is two ways of understanding speech.
The process of understanding a written text can be summarized, very broadly,
in the following way. We have seen that one of the results of the access process to
lexicon is giving meaning to the words inserted in a text; this along with the
Semantic and syntactic knowledge allows the reader to construct propositions.
(basic units of meaning) whose assembly and integration lead to the
construction of a coherent model of the text.
From our point of view, and following a dialogical approach (cf. Rornmetveit, 1974;
Volosinov, 1986; Wertsch, 1991), this final construction of a model of the content
The text does not emerge merely as an addition of the meaning of each of the words.
Any text is the result of a communicative action, where we can find
something like a kind of polyphony, a set of voices that interact with each other,
from different dialogues that the author has established with other authors, with other ideas,
knowledge and intentions, which have led him to construct the text of a certain
way. Obviously, when the reader approaches that text, another action occurs.
communicative where other dialogues are established with the purpose of
elaboration by the reader of another model of meanings and senses. In each case
there is an assimilation of the text to one's own world of knowledge, motivations and
intentions of the receiver. Thus, from the entire process of reading the text,
they generate new meanings, which will always be somewhat different for each reader.
It is necessary, therefore, to keep in mind that 'to understand' requires something more than knowing.
to read (in the sense of decoding words) and to know one's own language.
Evidently, decoding is necessary, but it is only a means to
understand what we read. In addition, we must take into account that the meaning does not
it resides in the words, phrases, or paragraphs, or in the entirety of the text, but it is the
result of an action by the subject, in such a way that the reader actively integrates the
information presented to you with your prior knowledge, in relation to your
purposes and motivations and within the context in which it occurs. The
comprehension is a constructive process based on the objective data that is presented
in a text and all the prior cultural information that the individual has
(stored knowledge, expectations, contextual clues, etc.). That is to say, if we
we ran into an acquaintance on the street and when we asked him how he was, he
Well, because I went to the doctor and got cured.
ambiguous, our general knowledge about the world allows us to understand
quickly that our interlocutor had a health problem, so he went to a
the doctor prescribed the necessary medicines for their healing. Additionally, we
we assume that the previous phrase is told to us with a specific intention and within the
context of our conversation, which can provide us with more clues about what
has wanted to tell us. On the other hand, thanks to the knowledge of our culture, we know
What are the functions of a doctor, and what is the procedure followed?
normally in our society when someone suffers from an illness. Like
we see, despite the fact that our interlocutor has not explicitly provided us
all the information we have pointed out, we have been able to understand perfectly and
quickly your message.
Consequently, it can be concluded that reading is conceived as a complex process.
and dynamic, through which the reader actively constructs a representation of
meaning that appears in a text, that is, it understands what is read, for this it is necessary
that relates the objective information contained in that text with
their prior knowledge; that is to say, there is an interaction between the text itself, the
reader schemata (the organization we have of our knowledge and that us
allows us to integrate and complete the information we receive), and the linguistic context and
extralinguistic. Therefore, reading is a cognitive activity that can be described
as a series of processes in interaction.
At the beginning of this section, we pointed out that when talking about reading, we can do so
from two different perspectives: the first one consisted of mentioning
reading process, something we have just described, so we will proceed to present a
second way to study this process, reading as a set of skills
what they must learn, in order to do this we will examine how the processes evolve
readers or, in other words, how a novice reader progressively stops being one
to become an expert reader.
Reading is, as we are seeing, a complex process and therefore requires
a laborious learning. The difficulty of learning to read in a writing system
alphabetical as it is in Spanish, is manifested in its slow learning in the field
school, and in the different types of reading problems such as traditionally
called "dyslexias". The difficulty of alphabetic coding is joined by the need to
certain conceptual skills, motivational factors, and habits on the part of the individual, great
part of which will be acquired thanks to the mediation of the teaching agents.
We can say that reading is a skill, that is, a complex action and
intentional that implies a set of processes, sensory and motor mechanisms, the
which through learning, experience, and internalization of content
etc., have come to organize and coordinate in order to achieve certain objectives
predetermined (understanding of a text) with maximum efficiency.
For a novice reader to achieve a proper understanding of reading, it is necessary that
maintain a consistent purpose and receive continuous feedback on
the result of his action. It is important for the individual to find that reading
it fulfills an important function for their life, not only as a tool for acquisition
of knowledge, but also as a means of communication or transmission of
information. However, reading skills have a cultural artifact nature
and require laborious learning, socially mediated - usually through
the parents, of the teachers and of the group of their class- that serves as a model and guide
of the necessary strategies to ensure that a person becomes a skilled reader.
If we observe a child who begins to read and compare them to our own
reading, we will notice multiple differences, for example, it is clear that he/she usually reads
slower (since the child needs to identify each letter), commits a greater number
of errors, with an incorrect intonation, etc. All of this leads the child to
to face a text has serious difficulties in telling us what it has read. It seems
that on one hand, a novice reader, due to their decoding problems, can
resorting to the strategy of basing your reading on something very similar to a process of
psycholinguistic divinations, that is, to engage in making assumptions about what
will appear in the text, without fully confronting them with the real information that appears
writing. On the other hand, a novice reader usually directs all their attentional resources to the
carrying out the most basic reading processes, so it cannot attend to the
meaning of what they read. In contrast, an expert reader does not dwell on the
identification of each letter, since it does this automatically, thus allowing
to dedicate greater attention to higher processes such as the construction of the
meaning of what was read.
We must consider other factors that evolve with experience, and that
they are also determining factors in reading, we refer to the knowledge that one has
reader about the topic he/she is reading and that plays an important role in the
understanding of a text. This knowledge can be specific to certain contents
(for example psychology and economics), in such a way that in response to an article about "the causes of
the devaluation of the currency," an economist manages to better understand and extract a
greater number of inferences that go beyond what is presented literally in it
article about what a psychology teacher achieves, whose training is in economics
more basic. Also, the classes of knowledge differ logically through the
development. The reading of a 12-year-old child and that of a 20-year-old adult is different, between
other things, due to each one's prior knowledge. Assuming that both have
adequate decoding skills for the same text, its understanding can
be different, since in the adult the volume of accumulated prior knowledge
through experience, learning, interaction with the sociocultural environment, etc., it is
greater than that of a child.
If we had to define what an expert reader is, we could say that a good
A reader is a good decoder and a good entender. The differences between good and
poor readers are based on their level of efficiency in both the most basic processes and
in the higher-level processes more associated with what we called understanding,
(these processes have also been called microprocesses by De Vega 1985 and
macroprocesses respectively) although the differential data indicates that in some
good and bad readers do not differ appreciably in the
macroprocesses, but yes in the microprocesses (Graesser et al, 1980; Adams, 1982;
Laberge and Samuels, 1974). As De Vega (1985) points out, "mediocre readers have
the same tendency to apply their syntactic knowledge in an anticipatory manner, but
on the other hand, they are less efficient in low-level skills, such as
recognition of letters, decoding of syllables and words" (p. 437). According to
this author, this is the reason why "bad readers often commit
substitution errors, which are semantically and grammatically plausible (e.g. "the
the carpenter took a "hammer", when in reality it says "the carpenter took the
mallet". The use of these top-down processes (macroelements) by
bad and good readers is attributable to the fact that they both share the same mechanisms
"constructive verbal comprehension, which are pre-reading skills" (p.437). Without
embargo, in other cases, a person considered a poor reader might be a
good "decoder" and being a bad "understander, in these cases, even if there are some
fluid decoding skills the difficulties would be in understanding the
text written (in the construction of a coherent representation of meaning). In
in these cases, the sources of differences between good and bad 'understanders' would lie in
the macroprocesses.
According to Perfetti (1985), a skilled reader is one who, in relation to their age group, shows
a comprehension and reading speed, at least, of medium level. The unskilled reader is
who is situated below the average level of their group, regarding compensation and
reading speed. For example, and in relation to reading speed, a
Clearly advance through the reading levels thanks to greater skill and
automation acquired in the use of microprocesses and macrprocesses. As
we were discussing the eye movements we make during reading,
we pointed out that younger readers capture 0.55 words in a fixation, while
what
adults capture 1.33 words in each fixation, which means (as can be seen
in the table presented below) that the first ones read on average at a
speed of about 80 words per minute, while the most skilled do it at a
speed of about 300 words per minute.

TABLE 6.3 - Evolution in reading skill with reading experience. Breadth

of fixations and reading speed.

Source: Taylor. Franckenpohl and Pettee (1960)

Everything we have said so far has aimed to be an overview.

complete what is understood to constitute the psychological processes that are put into
march in visual reading. Undoubtedly, tactile reading in braille will have many
common elements with visual reading, but, they must also necessarily have
differences. A good part of the rest of this chapter is intended to examine the
peculiarities that this type of reading presents.
The origin of the differences between braille reading and print reading lies, in good
part, in the sensory system on which the first collection of information rests
from the text. The fact that it necessarily has to be read with the tip of the
fingers in a always sequential manner presents a highly specific situation and
very different from that which occurs in visual reading, where each visual fixation collects
configurations formed by groups of various letters. The consequences are not limited
only to the size of the units of information that are collected first
instance, but they can go much further, affecting the speed at which
go through the text, in the way the stimulus patterns of the letters are perceived, or to
format in which information is stored. On the other hand, the peculiarities of the
tactile reading processes in braille do not exhaust themselves in the aspects that we just
comment. It is very likely that the later phases of processing will also be seen
affected by the way in which the initial processes are carried out. Let's think about,
example, in how a slower and more fragmented collection of sensory information
it can affect the memory processes involved in reading.
A thorough explanation of how the reading processes in this system are is necessary.
a detailed examination of the issues we have just listed, and even of some others
others. Our intention is not to point out the differences between visual reading and
tactile reading, but rather try, within the limits of possibility, to explain this last one by itself.
same, so that, once a greater understanding has been reached about
how the psychological system works in the face of this specific task, we can improve the
teaching the precise skills for using the braille system in reading
part of those who necessarily have to use it.
To this end, we will follow a scheme in our presentation that goes from the processes
from the most basic to the most complex just as we just did in the section
previous. However, we will not go into detail about the processes of
understanding in blind readers, as there are hardly any works at this time
on this aspect, perhaps in the belief that the problems of reading in the blind are
fundamentally focused on the basic processes of identification and coding of
the printed words.

3.2. Hand movement in tactile reading of Braille

The usual way of reading in the braille system is, as we all know, through the
touch. This section is dedicated to examining the way in which blind subjects
they use the tactile sensory system for the collection of the information included in the text.
We have already mentioned that the text is traversed in a smooth sweeping movement.
performed by the index finger of one or both hands: depending on the level of skill
reader that is possessed. It should be noted that there is no empirical evidence of the use of fingers.
different from the indexes. We find, then, that in the best of cases it is read
only with two fingers: the index fingers of each hand. Therefore, there is always one finger.
what goes ahead reading new material; the function that the second finger fulfills has
has been the subject of some controversy, which we will refer to later.
Most expert braille readers use both hands to read, which
results in a significant increase in reading speed. Mousty and Bertelson
(1985) in a study conducted with expert braille-reading blind adults
they found an average speed increase of 33% in bimanual reading in
relationship with one-handed reading. The maximum reading speed for two-handed reading is reached
when the reading skill of each hand is high and approximately equivalent
(around 75 words per minute; Mousty and Bertelson, op. cit.).
To examine the perceptual movements that occur in tactile reading of Braille
we will divide them into two sections. The first dedicated to the examination of the
finger movements, and another later focused on examining the patterns of
movement of the hands.

The movements of the reading finger

There are three types of movement that a finger makes in the process of tactile reading. A
horizontal movement, of "brushing", of the letters in the same direction as the line;
another sagittal, perpendicular to the previous one; and a third of pressure on the surface of
paper. Kusajima (1974) carried out an empirical study with subjects between the ages of 10 and 23 and
various levels of reading proficiency that allowed him to observe the relationship between this type of
movements and the level of reading proficiency. Their results enabled him/her
relate these two parameters through the classification below
we collect:
Clumsy readers: The fingers move across the material at a very slow speed and
uniform, stopping at each letter with movements of the three types. It seems that
it is mainly a task of successive form recognition
spatial that of a proper reading.
Average readers: They show an increase in reading speed as
the progress in the text. The number of finger fluctuations is lower than
case of the less trained readers (now it goes from 6 to 12 fluctuations per line
of 32 characters). Kusajima interprets these results as a consequence of that
task is no longer merely a perceptual process, but rather the reader's goal is to arrive
to the understanding of the text, for which it resorts to clues given by the text such as
contextual information, thus increasing reading speed.
Experienced readers: They read quickly and at a regular speed with few
fluctuations of the finger. Some up and down movements are observed at the beginning of the
words, while inside them the movement is fast and uniform.
Whenever reading is done with one hand, the finger goes beyond each
end of the line, making movements that can be considered as
unnecessary, but maybe they are dedicated to ensuring that there is nothing else there
text to read. However, the more lines are read, the fewer movements of this type
one can observe and it takes less time to move from one line to the next, so that in
normal texts end up adopting a rhythmic pattern of movements. In any
In case, it should be noted that at the moment a difficulty arises (characters
slightly marked, unfamiliar words, etc.) the process of finger sweeping is
stops, and this has to go back in a review process that it can do
patterns of movement typical of earlier stages of skill mastery appear
reader.
This last problem can, in part, be solved if instead of using a single finger one
perform a bimanual examination. But before moving on to the examination of how this occurs,
We will briefly refer to the controversy over which is the best hand to read.

3.2.2. The controversy over hemispheric dominance and reading proficiency of one or the other
hand

There has been a lot of speculation about the possible effect of specialization.
hemispheric in relation to the use of one hand or the other for reading characters
braille. The fact that braille characters represent a spatial configuration has
led some authors to defend the hypothesis that the left hand can
better recognize Braille characters than the right due to specialization
right cerebral hemisphere. For the moment, it should be said that the controversy continues in
the air, as the empirical data do not seem to be conclusive. Works such as those of
Graseman (1917), Bürkle (1917), Smith (1929), Hermelin and O'Connor (1971) or Harris
(1980), working with all blind subjects, present results in favor of that
supposed superiority of the left hand in precision and speed of recognition
of characters. In this same line, Rudel, Deckla, and Spalten (1974), Myers (1976) and
Harris (1980), working in this case with sighted subjects in discrimination tasks
touch of Braille characters whose meaning they did not know, they also found a
superiority of the left hand. However, other studies have not shown
differences in the use of both hands (Mommers, 1980; Bradshaw, Nettleton and Speher,
1982), although in this latter case the type of proposed task (goal search
semantic and phonological in lists of words and letters) is not equivalent to that of the
previous studies. Other studies have argued for greater efficiency in hand
right, as is the case with Holland and Fehr (1942) and Fertsch (1947), reaching
suggest that the contradictory results were due to poor control of the degree of
reading skills of the subjects studied.
Mousty and Bertelson (op. cit.) come to intervene in this controversy pointing out that the
superiority of the left hand is evident in tasks that emphasize the
spatial component of the cell configuration, as happens when working.
with visionaries who ignore the Braille alphabet or with poorly trained Braille readers. Without
embargo, at the moment when the character recognition processes are going
automating and the processing is done sooner, when tasks of a certain type are included
semantically, the dominance of the left hand would gradually disappear, and even
would observe a shift towards right-hand dominance. This interpretation
it would be consistent with the data from Hermelin and O'Connor (op. cit.), Fertsch (op. cit.) and Millar
(1984) that include this dimension in their respective designs.

3.2.3. Reading with the hands

It has already been noted that reading with two hands allows for increased speed.
reader and is, therefore, a sign of greater mastery of this skill.
Although this is not one of the favorite areas for psychological research, it
It is true that the study of the role of each hand in Braille reading is already old.
Heller, a student of Wundt in the Leipzig laboratory, already conducted a study on
this theme in the year 1904. This author argued that one hand performed a function
mainly analytical, while the other was fundamentally synthetic. The hand
the right would go ahead capturing the 'raw image' of the letter and the words, while
the left would then analyze the characteristics of each letter, making clear and
different impressions collected by the right finger.
This conceptualization of the function of the fingers made by Heller does not enjoy much
popularity today, although there is something he said that is true, because
there seems to be a certain division of labor between both hands. The left finger with
frequency serves an auxiliary function concerning the law, as in many cases
he is the first who makes reviews while the second continues progressing in the text,
thus maintaining the reading rate. On the other hand, it also helps through the
spatial location of some elements of the text (line beginnings, position of the
margins, etc.). In any case, these "auxiliary" functions do not exhaust the role that...
the left finger can execute, as we will see shortly, for very readers
trained is, in every sense, also a reading finger.
Various studies (Kusajima, 1974; Ochaíta et al., 1988) have agreed on the same
four types of hand movements based on the level of reading skill, that
we present below.
Type 1: It is the right finger that reads. The left finger remains at the beginning of the
next line marking where it starts and waiting for the change movement of
line of the previous one.
Type 2. Both fingers move one alongside the other, lightly touching and following a
course exactly parallel, both when reading and when changing lines.
Type 3. Both fingers move together and lightly touching from the beginning of
each line until almost the end where they separate. The right finger continues reading the
the rest of the line, while the left one jumps to the beginning of the next line where
both meet to continue the reading. Both movements are practically
simultaneously, without a noticeable decrease in reading speed. In
Sometimes the left finger has already started reading the new line before the
law is given to one.
Type 4: It is an evolution of the previous one. The left finger reads the left half of the
line, and the left reads the right half. Both meet in the center, moment at the
the left finger jumps to the next line. The coordination is practically perfect, always
there is a finger reading while another is changing the line.
Both type 3 and type 4, according to Kusajima, are typical of expert readers. It is with this
type of subjects with whom a team from the Experimental Psychology Laboratory of the
Free University of Brussels has carried out various works (Mousty, Bertelson and...
Hublet, 1981; Bertelson and Mousty, 1982; Mousty and Bertelson, 1985; Bertelson, Mousty
y D'Alimonte, 1985) some of whose conclusions are worth commenting on here,
precisely to clarify certain aspects of the transition from type 3 pattern to type 4.
These authors break down the hand movements in braille reading into the
people with certain skill in Braille in the following sequence: first of all, the
the left hand reads only the beginning of each line (left one-handed path
-TUI-), next the two hands together read the central segment (bimanual path
- TB-) And is finished by reading only with the right hand the end of the line (pathway
right-handed unimanual - TUD-). Practically in all right-handed subjects in this reading.
there is always a greater or lesser bimanual trajectory, which corresponds to the
what was said in the fourth pattern of hand movements of Kusajima. The amplitude of
this bi-monthly journey may vary among different readers, although there is usually a
very stable pattern of movements for each person. It is also interesting to point out
that, according to the authors of the Brussels group, reading speed is inversely
proportional to the length of the bimanual path. Subjects who read faster are
those who make a shorter bilateral journey; furthermore, these subjects are also the
faster in one-handed reading.
A curious phenomenon noted by these authors and that has also been observed by
Ochaíta and collaborators (o.c) is the very frequent presence among expert readers.
from the so-called 'simultaneous disjoint exploration'. This phenomenon refers to the
the left hand starts reading a new line while the right hand continues
reading the previous line. It should also be noted that in very fast readers this
simultaneous disjoint exploration barely reduces the reading speed of the
end of lines (something normal in braille reading), however there is a decrease
appreciable in the case of slower readers.
The presence of this pattern of text exploration raises some questions.
Interesting. Is it the case that the two hands read different parts of the text in a way
simultaneous? Or is it simply a division of functions between the two hands in
which both perform only complementary functions alternately for each other
the other?
These two alternatives have sparked widespread controversy among people who work
these topics. On one hand, there are those who argue that blind individuals, in
on occasions, they read two different segments of a text at the same time, one with their hand
left and the other with the right (Bürklen, 1932 and Kusajima, 1974). These segments
they are typically found at the end of one line and at the beginning of the next, which means that
it may happen that they are different letters of the same word, different words or the
the end of one sentence and the beginning of another. If this simultaneity in the reading is disjointed
it occurs, it is supposed that the subject at the same time has to integrate, to make sense
to the text, two pieces of information that can be different and that it receives independently of
one hand and on the other. Meanwhile, on the other hand, there are authors who consider, without
embargo, what is produced is simply a division of functions between the two
hands, in such a way that they perform complementary tasks (Foulke, 1982); for example,
while one finger reads a letter, the other finger explores the spaces between letters or between
words.
Millar (1987) conducted a research with the intention of precisely clarifying this.
controversy. To this end, he focused on the respective positions of the fingers during the
reading the central part of the lines (the bimanual trajectory of Bertelson et al.) as
in the line transition movements. The results, according to this author, do not support
the hypothesis that when a reader scans a line of text
together (the fingers of both hands together), each hand processes information from
different letters simultaneously. According to this author, what happens is that the fingers
readers fulfill different although complementary functions, so that when
one finger is reading a letter, the other is positioned in a space between letters or between
words. Even the phenomenon called 'simultaneous disjoint exploration', described
by some authors such as Bertelson et al. (1985), could not be considered as
different from the other one we just referred to when using registration methods of
most effective hand movements of employees by these last authors.
From these conclusions, a debate led by Susana has emerged.
Millar (1989) on one hand, and Bertelson and Mousty (1989) on the other. According to these
Finally, the results obtained by Millar (1987) are critiquable for two reasons.
methodological, one for the coding of the position of the fingers that is done in the
work, and another for the type of data analysis. Bertelson and Mousty (1989) make a
meta-analysis based on data obtained by Millar (1987), and conclude that
the new data obtained do not support the British author's position that the
readers systematically alternate the exploration of the letters with both reading fingers,
and that the absence of the movement pattern 'simultaneous disjoint reading' is due to
only to the type of population used in their study.

3.3. Perception and encoding in the tactile use of the braille system

Previously we pointed out that in the normal process of reading a text, there are
constant interactions between the basic processes of identification and recognition
of the words with the other higher-level processes such as the processes of
making inferences, building a text model, etc. In the presentation
Next, we will describe each process separately, in order to make it easier for
understanding the processes followed in the reading of blind people.
On one hand, we will look at the most basic processes and then we will analyze the
more complex processes that involve interaction between different sources of
information.

3.3.1. Perception and recognition of letters

One of the first issues to clarify when approaching reading processes

braille is the way in which characters are recognized and stored in memory
tactilely perceived. It has been maintained with some frequency that the
tactile perception of braille, in individuals who have reached a certain degree of skill,
it has a global nature. That is to say, it is recognized and remembered not so much as a mere
sequence of points, but rather the global configuration that constitutes those points.
This would be, as we have said, the case of good readers, while the readers
Few skilled individuals would perceive each braille cell merely as a set of dots.
For example, for them the letter 'c' would be formed only by points 1 and 4, while
For a good connoisseur of Braille, the letter 'c' has the shape of a horizontal line.
the top of the cell. This viewpoint has resulted in that
the possibility of other alternative reading systems for the blind is defended,
based on line systems and not point systems, facilitate a more easily
global image of a letter, which would result in greater ease and accuracy in the
reading for the blind. In fact, the old alphabetical system of Moon has never stopped being used
completely. It came to be considered valid, especially for those people who have lost
the view after learning the Roman alphabet of their language. Let us remember that in this
The raised lines form a stylized version of the regular alphabet.
In addition to the advantages in terms of accuracy and readability, they think these
authors who partly avoid the difficulties of printed intercommunication with the
written world of the seers, difficulties that persist with the Braille system. Even
various experimental works (Bliss et al., 1966 Thurlow, 1988) have attempted
demonstrate how this system and others derived from it (such as the so-called c5) provide
a tactile discrimination far superior to that achieved with the traditional system
braille. These same works not only assert that the notation systems that
They use raised lines to promote a lower number of identification errors.
braille, but are learned and read more quickly.
However, other studies continue to defend the greater efficiency of the systems.
of points. The various researches of Susana Millar (1977, 1978, 1985) reveal
manifest, in their view, that braille characters are better recognized as a system
of points that are formed by the symmetrical or asymmetrical aspects of the figures.
they say, they do not find much evidence that corroborates the idea that the increase in the
reading ability is related to a global coding, made up of lines that
they outline the general configuration of each of the Braille cells. Moreover, the
more skilled readers recognize the patterns of dots with greater accuracy and speed
that the line patterns. To tell the truth, in Millar's works it is never used.
a distinct alphabet from Braille, since when working with line configurations,
these are structured in the same position as the dots in the braille cell.
However, in fact, these recent investigations say nothing against other systems of
traced, which bear some similarity to the Roman alphabet. In a position
Intermediate are the data from Loomis's work (1990), which found no
differences in readability between characters formed by dots and characters
made up of lines. In short, it is not advisable, in any case, to discard the
possible use and development, in the future, of alternative systems to braille in the
measures that truly contribute something beneficial to the improvement of reading efficiency of
the blind in general, or those who have lost their sight after knowing and
use the current written notation. It is advisable to take into account that these differences in the
results on the efficiency of a procedure for presenting the alphabet on
Others may come determined by the teaching method. .

3.3.2. Braille Errors

One way to assess the potential coding problems that may arise in
the use of braille is the examination of letter recognition errors that
they do occur in reading.
The study of mistakes in reading Braille begins almost from the moment
historical context in which its use begins to spread. At the beginning of the century, the 'Uniform
Type.Comittee, an American committee dedicated to studying the possible advantages of
the punctuation systems, conducts two studies in 1913 and 1915 on readability of
the American Braille characters. They found that the readability was greater in the
characters that included a lesser number of dots. When these were analyzed
characters not in isolation, but constituting words, the most frequent errors
the appearance was the confusions between characters of the same number of points, but
with different configurations; they were followed by the omissions or additions of some point to the
typical of the cell used as a stimulus; and with a lower frequency appeared
errors of confusion between the vertical and horizontal positions of the characters. Despite
the methodological deficiencies of these studies, their basic results have gone
confirming in later American works that are much more rigorous (Ashcroft,
1960; Sowel and Sledge, 1986). From all of them, a similar gradation can be deduced.
type of errors that occur with this system due to their frequency of appearance.
The most frequent confusions were the omission of a point in the cell,
the easier it was to omit the recognition of those points the lower their
position within it (points 3 and 6), they were followed in order of importance by the
errors at the end of the word, the rotation of the configuration formed by the combination
from the points of the cell, the addition of characters, the coarse substitutions, the
changes in the column or in the row of a point, etc.
One of the studies we are referring to (Ashcroft, 1960) completed
his work with an evolutionary study to analyze the differences that occurred in the
number of errors made in braille reading as school level increased
of the subjects. While rotation and substitution errors decreased with age,
those of change due to phonological or lexical association and those of confusions in the ending
of words increased. However, the addition or removal of points and the changes
of vertical or horizontal alignment of points, confusions that are made
Specifically when using the Braille system, they remained more or less constant at...
long of the different school levels. As for the total number of errors,
these reached a global magnitude of 5.3 words for every 100 read, although that
the amount decreased with age, showing the 6th grade group at 41%
fewer errors than those of second grade. It seems that, although globally the
reading becomes more aligned with the text as the school grade increases, there are certain
specific braille system errors in which this decline with age is not
so appreciable.
In an experimental work carried out by our research group (Ochaíta, Rosa,
Fernández and Huertas 1988) aimed, as one of its main objectives, to
to investigate the type and number of confusions made by blind and visually impaired subjects
Spanish visuals when reading in Braille. The work also had, like Ashcroft's, a
evolutionary structure, so that five groups were formed according to the level.
educational: children in the first stage of primary education, children in the middle cycle, children in the upper cycle,
adolescents from BUP and vocational training and a final group of adults, teachers from ONCE. The
the texts they had to read were ordered from highest to lowest complexity, from a list
with all the Braille signs, going through a list of words and pseudowords, until
finish with different texts of varying reading difficulty. The results that
we obtained, obviously referring only to the type of confusions in reading, go in the
line that is presented below (see table 6.3.). In general, we find that the
specific braille system reading errors (omissions or additions of a dot and
letter rotations) were important in all tasks. In the list of letters
confusions arising from the rotation of the point configuration prevailed,
in contrast, the errors caused by the list of words were very similar
omissions or additions of points and those due to rotations. In contrast, in the reading of
The most common confusions were substitution errors or letter changes.
syllables by association or phonological and lexical confusion, similar to those that occur
in the reading of seers. In any case, the specific errors of braille continued
appearing in these texts to a magnitude similar to that of the previous ones.

TABLE 6.4.- Percentage of errors made in lists of letters and words

Source: Ochaíta et al, 1988

As for the number of errors made throughout the different
school levels, we found significant data for all tasks that
It was shown that as reading skills increase, the number of such decreases.
confusions. But we must emphasize that among the people more skilled in reading, the
group of teenagers and adults, from the few mistakes they made in their reading, the
most belonged to these specific braille confusions. With that, we return to
confirm that the braille system has inherent difficulties that maintain its
incidence at any reading level.
If we analyze each of these confusions, we can affirm that those who have
called "rotation errors" occur mainly due to spatial issues of
recognition of shapes or configurations. It is not so much, as has been thought during
at one time, due to a simple mix-up of one letter for another that is similar
but it is shown inverted, as if you are seeing its image in a mirror (for example
when the 'e' in braille is confused with the 'i'). The possible rotations that are
The difficulties faced by the visually impaired in reading are not limited to these confusions.
specular, many others appear where the rotation of the figure is more than 90° (for
example when the 'n' in braille is confused with the 'z'. That is why we think that
this error is caused by spatial positioning problems, in the difficulties
spatial errors of the reference axis of each letter. These rotation errors are in practice
more frequent in tasks of recognizing isolated letters, when there are no rules
grammatical or contextual that correct these recognition difficulties. Without
embargo, when it comes to reading texts, the frequency of occurrence of these errors
decreases (see table 6.4.).
The errors of 'omission and addition of points' could be explained as a
more "mechanical" perceptual confusion, due to the difficulty involved in tactile perception
to discriminate and specify exactly and at all times the points of a cell
braille as it is collected by the fingertip. On many occasions, the dot that
it is added or lost is perceived as a product of fusion or masking with the
letter that comes before the one being read. For this reason, these errors almost
they do not appear in the lists of letters and are more numerous in the lists of words. On the other hand,
in the texts, where the influence of context is greater, these errors decrease in
magnitude.
As is to be expected, the best way to avoid falling into these confusions is to
review again, the word that has left us confused. This fact that seems so
obviously it has its problems in braille due to the need to make movements
supplements of the hands. Let's remember that in tactile reading, re-reading a
a word already read implies making an additional effort to find the word again
doubtful. It's easier than it seems, in a reading where fingers are used, the
to make a mistake and jump to another line, to get lost or not to locate that word for a while.
This same thing logically affects reading speed and, very likely, has
repercussions in the later stages of processing:
Another issue to consider when we refer to recognition errors
characters is the possible effect of the familiarity of the characters used as
stimuli. Both in the work of Nolan and Kederis (1969) and in that of Ochaíta and
collaborators (1988) the letters that include in their configuration points 3 and 6 are
among those that concentrate a greater number of errors. In the case of the Spanish language,
these letters correspond to the last of the alphabet, from 'u' to 'z', some of the
which are not frequently used. In the work of Ochaíta et al. (1988) the set of
words that contained little-known letters (including vowels)
stressed) were pronounced in some cases in 38 different ways, producing
a total of 42 different errors.

TABLE 6.5.- Percentage of errors made in the texts, according to age level
Source: Ochaíta et al, 1988

This persistent presence of letter recognition errors within the cell

normalized 3x2 points of the traditional braille system makes us think that the
Foulke's suggestion to increase the number of points in the cells, mentioned above.
we collected, it can still produce a greater number of errors, for it necessarily
it would affect the sources of recognition problems we have been referring to:
greater number of points, more complex configurations, and patterns of presence
less frequent and, therefore, less familiar.

3.3.3. Phonological and/or Orthographic Processing

In relation to the basic processes of encoding, along with a first process

perceptive recognition of braille patterns, the reader undertakes a second
process of analysis or identification of the word as a unit of meaning.
In the studies conducted on lexical access in sighted readers, there is no consensus.
unanimous regarding the process that is followed to access internal representation of the
words stored in memory. Different models propose different ways of
access this internal lexicon. As a result, a confrontation has developed between
two stances: one that considers that access to the lexicon occurs through the
use of a single pathway, which in some cases has been considered to be phonological
(for a review see McCusker, Hillinger, and Bias, 1981); and another, which is precisely the
What additional support has been received (Morton, 1980, Morton and Patterson, 1980,
Coltherat, 1978, Patterson and Sewell, 1987), which supports the existence of two pathways, one
orthographic path that provides direct access to internal lexicon through the
orthographic representation of the word, and a second phonological avenue that implies a
previous phonetic encoding of the written word. The use of one route or another will be
based on reading skills, the characteristics of words and the context.
We still have another stance that supports the existence of more than two routes, such as
This is the case of Seymour (1986) or Schwartz (1984), who describe three routes for
access the internal lexicon (for example, in Schwartz's model, 1984, it is shown a
visual route, another orthographic one, and a third phonological one.
This diversity in access routes must be complemented by the possible changes that may occur in them.
they occur as reading skills increase. According to some authors,
subjects who learn to read go through a series of stages or phases in which they
they acquire the ways or routes that we have just described (for example, see Frith, 1985;
Seymour and Elder, 1986. .
In the case of reading for the blind, the data we have today about access
lexicon, apart from not being very numerous, lacks great homogeneity and rigor
methodological, since in some works the degree is not effectively controlled
of the subjects' blindness, in others different tasks are used to measure the same
reading process, with what really the cognitive operation that must be performed by the
subjects may be different. Thus, to study direct and/or indirect coding in the
access to the lexicon some authors use tasks basically of lexical decision (Pring,
1985, Krueger, 1982) and named braille words (Pring, 1982), while others
they study the same processes with a recall procedure of a list of words
braille (Millar, 1975; 1981). In many works, moreover, there is no distinction between good
and poor braille readers and when it is done a common criterion is not shared
differentiation, as in some cases age is used (comparisons between children, -
adolescents and adults), while in others criteria of differences are used in
reading speed; sometimes, it is not even specified the criterion that
it is used to differentiate levels of reading proficiency. As a consequence, it is quite
it is common to encounter contradictions among various authors when referring to
these processes of analysis and coding of information written in braille. Our
the intention will be to attempt a description of the evolution of these processes
coding increases as reading skills in blind subjects improve. The image that
It results from the integration of all the empirical results that are now available.
obviously it may undergo substantial changes in the future, as long as it
progress in the study of these processes.
The tasks and materials used to study lexical access in blind readers.
son, in many cases, similar to those used to study these same processes in
the sighted readers. We have already mentioned that procedures are usually used to
lexical decision, naming, and recall. The first of these consists of recognizing
from a list of words and pseudowords those that correspond authentically
with the vocabulary of their language. The naming procedure simply consists of
in reading a series of words that are presented to a subject as quickly as possible.
In the third procedure, the recall one, the subject after reading a list of words
Proceed to repeat those that you remember. The most commonly used materials in these two.
procedures have been word and pseudoword lists, which may be similar
and/or phonetically and/or tactilely dissimilar (for example, Millar, 1975, 1984; Pring,
1982, 1986; Ochaíta et al. 1988, Fernández t.agunilla, Rosa, and Ochaíta 1988). Also
regular and irregular words can be used in their grapheme correspondence
phoneme (Pring, 1982). At other times, lists of familiar words are used and
unknown or new to the reader (Pring, 1984).
Below we will provide a description of the general phases of development of the
reading that follows a blind reader, and that will allow us to locate the different stages and the
strategies that they use at each stage to access internal vocabulary.
One of the most accepted models to explain reading acquisition in
readers with sight is proposed by Frith (1985). This model describes three
qualitatively different stages that must be acquired successively for a
The reader seer possesses good reading skills: logographic, alphabetic and
orthographic. The data we will present about blind readers does not depict a
development guidelines absolutely identical to this model, but we consider
It's interesting to make this comparison to organize the data we have.
The first phase described by Frith (op. cit.), the logographic phase, is clearly distinct in the two
types of readers (sighted and blind). In this phase, sighted children would be able to
recognize, for example, the word "Coca-Cola" by its anagram, simply by identifying
the configuration of the word and its spelling as a whole, without being aware of the letters
that compose it. However, in the case of the blind, we cannot speak with
property of there being a logographic level.
For the visually impaired, the first level of reading development is characterized by being
centered almost exclusively on perception and an initial tactile recognition of
the braille settings. That is to say, these children dedicate almost all their attention to
recognition of the arrangement of the cell points, without integrating them into
a global configuration to subsequently relate each arrangement of points
with a letter of the alphabet, hardly managing to integrate each group of letters into one
word. Practically all attentional resources are dedicated to these processes
perceptual-tactile, as their reading skill is so limited that they do not even reach the
identification of words as a unit of meaning. It is not easy to specify the
age at which this first level of coding occurs, because it is closely related
linked to the acquisition of certain cognitive skills, at the moment when it occurs
reading instruction and its effectiveness and quality. In our work (Ochaíta and
In 1988, we found some blind children in residential education who were 8-9 years old.
years were still at this first level.
However, it seems that in the next phase proposed by Frith, the alphabetical one, it does exist.
a similarity between blind and sighted readers. In the alphabetic phase, the main task
both for sighted readers and for the blind, it is to learn to transform the
graphemes in their corresponding sounds through the use of rules of
grapheme-phoneme transformation. At this moment, the subjects are using an indirect route
the phonological to access the lexicon. As practice with braille increases,
readers focus mainly on the phonological coding of braille signs
(Millar, 1984; Ochaíta et al., 1988). Therefore, reading follows a sequential process of
perceptual recognition of Braille patterns (the letters are perceived as shapes)
geometric) that ends with the phonological analysis of them. The blind reader of this
level is converting, in speech the tactile patterns as they explore them.
way that when they run their fingers from one cell to the next braille pattern, the
Phonological coding helps them retain auditory content in their memory.
previously, in such a way that, in the end, through a successive integration, they manage to obtain a
phonological representation of the word in its entirety. Ultimately, little by little and
through this sequential process they manage to attribute meaning to what they read. It is
It's easy to understand that at this moment, reading is very difficult, laborious, and little
attractive. As their reading practice increases, so does their
knowledge and vocabulary gradually speed up this process. At the end of this
In the second phase, readers have access to knowledge that is sufficiently
flexible enough to understand the relationship between the reduced number of phonemes of a language
(especially in languages like Spanish) with the multiple combinations of the
the same that constitute the vocabulary, accessing the internal lexicon through the
use of an indirect or phonological route. Ochaíta et al., 1988 found that the
children aged 9 to 13 were carrying out a reading similar to the one we have just presented.
Regarding the spelling phase, we cannot consider it equivalent for readers.
seers and blind readers, In this phase the sighted reader is able to access the lexicon
not only through an indirect route but it can also recognize some words
through a direct or orthographic route. In the case of blind people with reading practice
are reaching a certain automation of these coding processes, that is to say, the
they are carried out more mechanically, with less effort and with less voluntary control.
So that in the face of not very complex texts, with familiar content words and in
good printing and braille reproduction conditions, accessed in a 'more
rapid" to the identification of the words of the text, that is to say, they could end up identifying
the word without the need to make a phonological coding of it all
(Krueger, 1982, Millar 1984, 1988, Ochaíta et al., 1988, Pring, 1982, 1984). In this
It is necessary to make some clarifications: it can be dangerous and confusing to carry out
an analogy between what is called 'direct access to the lexicon' in seers and what
In the blind, we consider it a 'faster access to the lexicon.' As is obvious, the
blind readers cannot perceive with their fingertips the configuration of a
word in its entirety, as actually happens with sighted readers in one go
visual fixation, what we do believe happens is that, in the face of certain words
known, the blind reader when recognizing the first letters can begin to infer from
what word is it, without needing to explore all the characters that compose it.
This process that we could call 'inferential access' causes the reader
often makes mistakes related to the ending of the word, as we will see
later.
However, at the moment when the subject finds the content little known
text that he reads, or when he encounters words that are barely legible due to distortion of the
material, it needs to resort to a more detailed coding, once again phonological, to
ensure understanding. In practice, adult blind individuals with reading skills,
they still occasionally carry out these intermediate processes of phonological coding
more frequently than those with the same level of development.
This fact reflects that blind people take more time and effort to achieve
an adequate knowledge of written language than the sighted. According to Frith (1989)
These "skills" seem to increase spectacularly in normal sighted children.
between the ages of 7 and 8, in front of the blind children who, according to the data available
we have, it seems that they begin to develop these skills starting from,
approximately 14 years old. Thus, the last stage of reading development, the
spelling in the seers, only the blind readers seem to fully acquire it
starting from adolescence.

3.4. The influence of context on the reading of the blind

As we saw in the introduction to this chapter, reading is a cognitive activity.

complex in which a set of perceptual, linguistic skills are involved
conceptual. Ultimately, when we read a text, our main objective is
understand the message embedded in that text, but to achieve this, necessarily
we must decode the signs written on the page. That is to say, the decoding is a
means necessary to give meaning to said text. There are factors in the text itself that
influence the decoding process and that, depending on reading skills,
they can have a facilitating effect on that process. We are referring to the use
from the context in the reading, that is, one of the means that the reader uses to
accessing the meaning of words is the use of the keys given by the very
Words are perceived more quickly in a meaningful context than in
a meaningless context or in isolation, it must also be taken into account that the
words are usually not perceived in isolation but are produced in their
natural environment, that is to say, in meaningful sentences. Thus, and following an example used
According to Crowder (1985), we recognize the word 'BURGUNDY' more quickly when
We are reading something about France or wine, which is about kangaroos.
In most studies conducted on the effects of context on reading
braille, it is verified that blind readers rely on it during their reading. Although
The seers can also resort to contextual information when necessary.
the use made of this is not the same for sighted readers as it is for the blind. Let's explore.
this difference with certain care.
Good sighted readers rely less on the
indications given by contextual information to make inferences about the
following words written. This is because these subjects have it so automated
the basic processes of decoding, which is the recognition of words
produce immediately without the need to resort to other strategies such as the use
of the context. These readers efficiently resort to the context when necessary,
for example when they encounter difficulties in reading (new words,
misspelled or blurry words, etc.), to compensate for these difficulties.
However, poor sighted readers do not have these processes automated.
basic decoding, relying on other sources of information such as context
to make inferences about the words of the text, which allows them to enhance their
reading speed, and in this way compensate for their lack of reading skills. This
It obviously leads to the occurrence of errors in word identification.
In the case of blind people, both good and bad Braille readers are
influenced in their reading by contextual information but the effect that this exercises on
These two types of readers are different. Good braille readers rescue from their
long-term memory the name of tactile patterns known more quickly than
the bad blind readers, for they will have more time than the latter to
formulating and checking inferences as they read. These readers, despite
need to use fewer compensatory strategies than novice readers, such as would be the
by relying on contextual information, they are able to use these strategies when it is
necessary (for example, when there is difficulty identifying Braille characters,
when there are errors in the characters leading to incorrect or nonsensical letters,
when letters are missing, etc.). In this way, when faced with texts with this type of errors, they are able
to give meaning to words that do not have it or to correct typos based on the information
provided by the context (Ochaíta et al., 1988). However, poor readers
braille, they will dedicate all their attention to the most basic processes of decoding, not
being able to use attentional resources in the confirmation of their
expectations based on contextual information. Therefore, in the presence of texts with words
with errors they are not able to replace them with other words in line with the
information given by the context.
There is experimental evidence that supports this interpretation. Specifically, Ochaíta and
col. (1988) conducted a research in which they presented the subjects with texts in the
that intentional typographical errors appeared in such a way that the printed word did not
it was a real word but a pseudoword. The corrections made by the subjects
When reading the texts, there were three types: a) ADDITION consisted of adding or giving meaning to the
pseudoword in such a way that they said a syntactically and semantically coherent word
with the content of the text, b) CHANGE consisted of replacing the pseudoword with a
word that was syntactically coherent but semantically incoherent with the text
and c) REMOVE consisted of replacing the pseudoword with a random word in a way
that this word was completely incoherent syntactically and semantically with the
content of the text.
The authors verified (as can be seen in table 6.6.) that in response to a text
in which errors appear, as age increases, and consequently skill
Reader, subjects are becoming capable of correcting errors according to the
contextual information, replacing them with words coherent with the text
presented.

TABLE 6.6.- Averages corresponding to the type of corrections of the pseudowords

taking into account the age.

In other works such as Pring's (1984) where the material was presented under two
conditions (with degraded points and without degradation) it was found that in subjects
blind individuals, a significant effect of semantic facilitation appears under conditions of
normal readings (with the points unchanged), but this effect disappears when the
stimulus is degraded, as the reader must devote more attentional resources to the
analysis of character traits. Another piece of information that shows the influence of the context
in the reading of blind people, it is provided by Mousty and Bertelson (1985) and
Simón, Huertas and Ochaíta (1992) who proved that reading speed is
increases according to the increase in contextual strength.
With what we have seen so far, we can say that the differences among braille readers
regarding the readings of the seers, they can be explained not only by differences in the type
of information processing, but also because of the different type of notation
used and by the perceptual system that is employed. Braille is a complex system and
with readability difficulties that reading in ink does not present. Furthermore, not
we can forget a characteristic aspect of the braille system, already mentioned in
previous sections: the braille system, as noted by Pring (1985), is not very redundant,
that is, a failure in the identification of a point may cause it to be identified
an erroneous letter, and consequently, the word is not recognized correctly.
the one that is part of. This does not happen so easily in reading ink, since in
this can perceive groups of letters in a single fixation, so that when perceiving the
word as a whole can easily resolve possible ambiguities in
the letters that compose it.
Therefore, it is logical to think that if the braille system is more difficult to be perceived by the
blind people like ink for the sighted, the effect of text degradation must be
also more important. Indeed, when texts with points are presented
blurred (with reduced relief), this degradation exerts a greater magnitude effect
that in the case of ink, a good part of the processing capacity of the
information, which is usually dedicated to examining the semantic information, should be
used to identify the letters in the condition of degradation, and therefore the effect
the context significantly decreases (Pring, 1985). According to this author, if
we would reduce the redundancy of the printed text and at the same time degrade it,
it could be expected that the effect of semantic facilitation would also disappear for the
sighted readers.
Therefore, we consider that unlike what happens in the reading of the
expert seers, the expert blind subjects always use, to a greater or lesser extent
measure, the contextual clues to facilitate the identification of written words.

3.5. The speed of tactile reading of Braille

Reading speed is being considered as an index of reading skill or

the difficulty of the text to read. We also know that there is a connection between the
the manner in which written information is collected (the breadth of visual fixations and
the number of saccadic movements in the case of visual reading) and the speed of
reading. On the other hand, the timing data is extremely useful for inferring to
based on them, and with the help of theoretical models, the type of mental operations that
subjects develop. Therefore, we consider that the data that we will present next
to present provide an important foundation for the discussion of the peculiarities that
presents the tactile reading of braille.
The average reading speed in Braille is a relatively well-studied area.
Table 6.7 shows the results obtained from different studies;

TABLE 6.7.- Averages obtained in research on Reading Speed (averages

expressed in words per minute
Authors Middle School Grade
Hayes (1918, 1920) 1° 30
Ochaíta and col. (1988) 1.°_2° 34
3°_5° 43
Lowenfeld and Abel (1967) 4th 84
Athearn, Campbell and Lavos (1944);
Niday (1939); and Lowenfeld (1945). 4° 53
Nolan (1966) 4°-6° 55
Meyers and Ethington (1956) 5°-8° 63
Foulke (1962) 6°-8° 57 (1)
70 (2)
Ochaíta and col. (1988) 6°-8° 82
Athearn, Campbell and Lavos (1944);
Niday (1939); and Lowenfeld (1945). 8° 65.5
Lowenfeld and Abel (1967) 8° 149
Hayes (1918, 1920). 9° 83
Nolan (1966) 912° 70
Ochaíta and col. (1988) 9°_12° (BUP) 88
adults121
Meyers and Ethington (1956) 9°_12° 86
adults90
Foulke (1964) adults104
Grunwald (1966) adults 200-300
Kilpatrick (1985) adults79 (3)
adults177 (4)
Mousty and Bertelson (1985) adults85 (3)
adults135.(4)
texts from a science manual considered difficult.
(2) literary texts considered easy.
(3) subjects considered as average readers
(4) subjects considered as fast.

These data deserve to be discussed in some detail, but before that it is advisable
make some clarifications. First of all, it should be noted that these are data from three
American, Belgian, and Spanish. On the other hand, the jobs
North Americans, in addition to being produced with texts in the English language, use the
braille type 1 1/2 (a contraction system no longer in use) or type 2. On the contrary,
the other research that we collect here, besides being conducted in languages
romances use uncontracted braille texts.
Despite the linguistic and textual differences, it is important to highlight the almost complete agreement.
In general, the reading speed in Braille is much lower than that of visual reading, and
this speed progresses very gradually as age and level do
of instruction of the subjects. It is striking to note that there does not seem to be a
notable effect of the presence of contractions in the text on reading speed
(a discussion on this point can be found in Nolan's fourth study and
Kederis, 1969); nor does the difference in languages seem to have any influence. For
the rest, the data found in the different works are mostly from the
almost coincidental occasions.
However, we can find discrepant results regarding reading speed.
the adult subjects. Let us briefly pause at this last point, without prejudice to
that we insist on it later. As can be seen, the average data
for this group range between 79 and 300 words per minute in the worst and in the best of
the cases respectively, although the most common data ranges around 100
p/m. How can we interpret this disparity? Let's first look at the
Grunwald's work is where the most striking results are presented. There is a
general consensus among scholars on this topic (Nolan and Kederis, 1969; Foulke,
1982; and Kilpatrick, 1985) that these data are extremely atypical, whenever,
Moreover, the procedures used by this author deviate from those generally
employees, both in the presentation of the material and in the computing procedure
of speed, as well as in the absence of control over the understanding of the text by
about their subjects, something necessary in the experiments on this topic. All of these
particularities lead us to interpret their conclusions with great care. Without
however, Grunwald's work requires careful discussion that we postpone.
for later. Another study, that of Lowenfeld and Abel (1967), also presents
reading speeds higher than those of other jobs, but they can also be
explained by the extreme simplicity of the very brief text they used, as well as that
These authors also did not control comprehension in any way.
Kilpatrick's work (1985) differentiates between average readers and fast readers, the
they are capable of reading at an average speed equivalent to 177 wpm. If we examine
By carefully analyzing your data, we can realize that it is only about 6 subjects, from one.
of which it is said to reach a speed of 331 p/m, while the five
the remaining have a reading rate that ranges between 132 wpm and 180 wpm, with an average,
excluding the fastest subject we just mentioned, of 156 p/m. A speed in
any case high for treatment of braille reading, although it is no longer far from the
media obtained from other research.
The effect of text complexity on reading rate has also been the subject of
some studies. This aspect had already been taken into account in Foulke's work
(1962) that we collected in table 6.7.; the difficult texts (extracted from a manual of
Natural sciences) were read much more slowly than narrative texts. The
the work of Mousty and Bertelson (1985) also studied the effect of the type of text, in
concrete they used passages from a novel, a selection of sequenced words from it
same novel (order 7 approximation) and a text composed of words gathered at the
chance, observing a facilitating effect of the context. However, Ochaíta's work
y col. (1988) found no differences between reading a text with errors.
intentional and another equivalent but without mistakes when a reading was done
silent. In any case, it should be noted that the presence of these typos does not
it represents a disruption of meaning or difficulty of the text as significant as that of
the previous works. However, when the reading is done aloud, they did appear.
differences between one text and another. It seems as if the effective pronunciation of the
words with typos would lower the reading rate, probably because of that
to see the awareness of the existence of those errors.
Precisely this last aspect, the presence or absence of differences in the reading rate
between silent reading and reading aloud, has also been a subject of attention and
with quite coincident results. There are no differences when the texts are and they
present in comparable conditions, in this they agree with works such as those of Nolan and
Kederis (1969), Foulke (1982) and Ochaíta et al. (1988).
In short, from the work we have reviewed, it seems to emerge that the rate of
Braille reading progresses very slowly as age advances, and especially the
reading instruction, with the latter factor being responsible for the differences that
can be observed among blind from birth and late (Mousty and Bertelson, 1985) or
between totally blind and visually impaired individuals who read braille (Ochaita et al., 1988).
lastly, except for some exceptions that we have already discussed, it seems that adults
they can hardly reach a reading rate close to 150 words per
minute. The possible significance of this data will be the subject of a more detailed discussion later.
go ahead.

3.5.1. Reading speed and hand movement

An obvious question that arises when considering the reading speed in braille is the
possible relationship that can be established between the patterns of manual exploration that
they possess the subjects and the reading rates that they exhibit. The data that has so far
what we have managed in what we have exposed in this chapter seems to point towards the
supporting the hypothesis of an almost direct relationship between one and the other aspect.
Some experimental data also seem to support this same hypothesis. The group
from Brussels, which we have mentioned repeatedly, (Bertelson, Mousty and
D'Alimonte, 1985; Mousty and Bertelson, 1985) has worked on this aspect.
making some findings that deserve to be commented on. First of all, it seems that the
reading patterns of adult subjects are very stable. Secondly,
they found that reading done using both hands is much faster than
the reading that is almost always done with one hand, with an average gain of 33%; to
It should be added that the gain in speed is greater when the differences in
the reading rate between the two hands is not very high. Thirdly, it was placed in
I declare that the difficulty of the text affected the modes of exploration, increasing
the bimanual trajectory according to the text became more difficult, decreasing at the same time
time the reading speed. On the other hand, these authors studied the moment in the
that the index finger of the right hand initiates the return or jump movement to the line
next without being able to find significant differences between the four groups of
observations that were considered (blank spaces, first cell of a word,
last cell, or intermediate cells). Lastly, and for what interests us most now,
the subjects who had a shorter bimanual trajectory, that is to say, those whose
hands act more independently, are precisely those that achieve a
higher reading speed. It seems, then, that this pattern of disconnected bimanual movement
it is the one that enables a higher reading rate; however, it should be taken into account that
the subjects selected by these authors were precisely because of the fact that
they were always bimonthly readers.
Other works, such as Kilpatrick's (1985), also point out this relationship between
hand movements and reading speed, highlighting that simply saving
time that allows you to continue reading with one hand while the other skips from
line can represent a 12% increase in the reading rate. However, this
A linear relationship exists when we refer to the general trend of the group of subjects.
from Kilpatrick's work, but this seems to lose part of its significance
when we stop to examine the individual behavior of the different
subjects that make up each of the two groups of fast and average readers with which
this author works. On one hand, it should be noted that none of the average readers
he was using a pattern of independent hand movements, while this was
the case of half of the fast readers. But what stands out in the case is that 1/3 of the
speed readers will use only their right hand while among them
precisely the individual who reaches the maximum reading rate. To try to explore
if there was any effect of the manual exploration style on the Kilpatrick reading rate
divided his subjects into three groups: one-handed readers, two-handed with movements
parallels of the two hands, and bimanual with independent movements of the
hands. The result of the analysis of their data matched what was expected if the conditions were nullified.
data of the atypical subject we referred to earlier. Therefore, the data of
Kilpatrick would agree to relate the patterns of hand movements to
reading speed, as previously noted by other authors (e.g.
Bertelson, Mousty and D'Alimonte, 1985; Eatman, 1942; Kusajima, 1974, etc.
In line with the argument we have been presenting, it can be inferred that it is
it is possible that through training programs the speed can be increased
reading, either by modifying the manual exploration patterns in the
to the extent that it is possible - or through the implementation of collection strategies
from the information situated in the text. Fortunately, there are works dedicated to the
exploration of these possibilities whose contributions we will now focus on.

3.5.2. Attempts to increase reading speed through programs of

training

The experimental works carried out with this objective can be grouped into three.
categories based on the type of methodology they use.
The first group uses a methodology based on overtraining in the
tactile recognition of Braille cells corresponding to different letters,
using either character lists, or, at times, an instrument
called "taquistotactometer" which allows for controlled time exposure of
braille letters. The results, however, have not been conclusive in any case. For
For example, Henderson (1967) managed to increase the rate of his experimental group.
oral reading, but, nevertheless, he did not manage to increase his reading speed
silent. Neither Flanigan and Joslin (1969) nor Umstead (1970) managed to increase
the reading speed of its subjects in a significant way.
Another system used has consisted of manipulating the speed at which the
the text slides under the reader's finger. For this purpose, devices have been designed that,
using an adjustable speed motor, they allow movement under a window on
the one resting the finger on a strip of paper on which the Braille characters are engraved
that constitute a text. The results with this technique are not conclusive either.
Both Flanigan (1966) and Kederis, Nolan, and Morris (1967) or Stockton (1965)
significant increases were found in the experimental groups with which
they worked, but the results of the control groups do not allow attributing the
earnings from the first ones clearly to the training program that
they received. In any case, there are some data from these works that result
interesting and in favor of this type of training. The subjects who suffered
these intervention programs then made fewer review movements and fewer
fluctuation movements that occurred before the treatment, which was not the case in the
control groups. This may explain the higher rates of subsequent reading offered.
for the group that had followed the training program. On the other hand, the subjects
those with lower reading skills seem to achieve more gains with this training than
those who already had a good reading rate.
A third methodological approach to increase reading speed is,
obviously, proposing the change of hand movement patterns in a way
to achieve maximum benefit from their movements, thus being able to
to cover a greater amount of text in the same time. Surprisingly, it has not
There have been works that have tried to train the types of movements that we know are the
more suitable as we have already had the chance to examine. The strategy followed in
some jobs have been little directive, in the sense that they have not been proposed
patterns of hand movements, but has involved creating workshops of
training on reading where the readers communicate with each other
various text scanning techniques and perform reading exercises. Works like the
from Crandall and Wallace (1974); Hodson, Hoeksema and Weiner (1974) and Olson (1975) have
it is evident how it is possible through a training, in which the
social motivation plays a very important role, substantially improving the rate of
reading.
What conclusions can be drawn from the review we just conducted? Firstly
place where the reading rate can be increased with training programs, although
it seems that this can be achieved fundamentally through manipulation of
motivational variables (Kilpatrick, 1985); in any case, this is an area that
clearly needs more research. Secondly, they are the readers with
more moderate rates are those who benefit the most from these programs
training. The third conclusion emphasizes a topic that we believe is
considerable theoretical interest. No study reports that as a result of
training, they are
achieved average reading rates above 130 wpm. This makes the rates of
reading of what these studies inform is very close to the data obtained in the
observational studies on reading speed, both European and
North Americans,
that we have reviewed before. This coincidence of results leads us to consider a
question to which we dedicate the following section to its formulation and attempts at answering.

3.5.3. Is there an absolute limit to the reading speed of tactile Braille?

A problem that has concerned researchers, and that we will examine later
with certain care, it is whether or not there is a certain absolute limit to speed of
tactile reading of braille. Literature, as we have seen, offers information that is difficult to
reconcilable positions that we can group into two stances. One refers to the slow speed
maximum reading speed reached by most expert braille readers (something
less than 150 p/m). While the other refers to the fact that some subjects present a
very high reading rate (above 200 e, even up to 250 p/m). How is it possible that
How can data appear with such a huge disagreement? We have already discussed
some extremes of the jobs that offer data on high reading rates and that
they raise doubts about the legitimacy of comparing their results with those of the
However, the doubt about the existence of exceptional subjects remains.
which, it seems, reach reading rates higher than those normally observed.
Can any explanation be offered for this?
disparity?
The main core of Kilpatrick's work is precisely aimed at trying
answer this question. To do this, start from the two fundamental hypotheses that exist.
in the previous literature on how tactile reading of braille is performed.
The sequentiality hypothesis was formulated by Nolan and Kederis (1969). These
authors argue that braille reading occurs through the gathering of information
of the text letter by letter, in such a way that this information must be stored in the
memory until it reaches a sufficient volume to allow for the identification of a
complete word. Consequently, the time to identify a word would include
the precise time to perceive each letter, along with the necessary time to integrate that
previously stored information and thus identify a complete word. According to
these authors, the braille reading process relies on a serial perception. There is
some data that supports this hypothesis. Nolan and Kederis distinguish between what they call
"coverage time", which would be the time that a subject effectively spends on
to go through and identify a word, and "synthetic time," which they conceptualize as the
sum of the recognition times of each of the letters that make up a
word, according to previous experiments conducted. Their experimental results
they show how the coverage time is generally greater than the synthetic time,
except in the case of very familiar words where they assume that the subject is capable
to guess what the characters are at the end of the word, thus reducing it,
due to the implementation of different processes, the observed coverage time.
Precisely the seriality of the reading process is what would explain the low rates.
of reading that the blind present. According to this conception, both novice readers
how experts would basically perform the same operations, with the difference of
that these last ones would avoid unnecessary movements and would be faster in the
execution of these operations.
The hypothesis of rhythmic patterns. This second conception, already defended by
Grunwald (1966) argues that the high reading rates observed in some readers
Braille experts owe it to the fact that they do not perceive the text letter by letter, but rather they are
able to recognize the total shape of a word through the 'tactile rhythm' that,
temporarily extended, it would be perceived when transporting the fingertip with a
smooth and continuous movement over the points that make up a braille word.
Consequently, readers would not perceive the text letter by letter, but rather through the
recognition of the tactile rhythm of a complete word. According to Grunwald this
it would explain why some readers might reach very high reading rates. On the other
part, the type of hand movements observed in expert readers, very
smooth, at a constant speed and without fluctuations, would be compatible with this hypothesis. In
definitively, this hypothesis would not deny the previous one, but rather asserts that readers
quickly change their information gathering strategy.
Kilpatrick (op. cit.) aims to explore whether this difference in strategies occurs.
between fast readers and normal readers. Their results do not support the
Grunwald hypothesis, as there are no significant differences among fast readers
and slow readers in aspects such as the difference between coverage time and time
synthetic, or in the time of recognition of long and short words.
There are also no differences in the type of hand movements, although with the
nuances that we have already pointed out earlier. Therefore, the data presented by this
authors seem to support Nolan and Kederis' hypothesis more than that of
Grunwald. The only difference he finds between both groups comes from a
interview that administers to its subjects in which they are asked to report on the type of
strategy they employ when reading. Subjects with moderate reading rates report.
who are generally aware of each person's individual perception
characters, while most speed readers indicate that they are only
aware of the words. Kilpatrick points out how this data alone is hardly
it can be considered very significant, but it points to the possibility that the
the difference between fast readers and normal readers may lie in that the latter employ
processing time in a conscious process that could become automated.
This argument at the present time lacks more support than what we already have.
exposed, and points out a possibility to explore in future research. The truth is
that, for the moment, there is no experimental evidence that allows to challenge the
explanatory hypothesis of sequential recognition of characters that had already been indicated
Nolan and Kederis.

Although it is difficult to give a definitive answer to the question we started with

this section, especially when there are data from some subjects who are capable of
achieve relatively high reading rates, the arguments we have just discussed
leads us to consider that the tactile reading of Braille indeed seems
necessarily have a sequential nature, which forces the use of a set of
resources that consume time. This leads us to think that indeed reading
tactile would necessarily have to be slower than visual. In any case, it seems
of course at the moment we cannot provide an answer to the question with the
that we begin this section referring to how it is possible that there are exceptions to the rule
of a generally slow reading rate. However, the possibility remains open to
effectively testing the hypothesis of the influence of sequentiality.
Let's now examine this issue.

3.5.4. The issue of sequentiality in braille reading

It seems, then, based on everything we have said so far, that it is precisely the
necessary sequentiality with which braille characters are perceived in reading
manual imposes certain limits on the reading speed in this modality.
However, to be able to affirm that this is indeed the case, it is necessary to examine
previously if this may be due to other sources of variation.
A first aspect to consider is whether the characteristics of the tactile sense itself impose.
a time limit on the perception that could have a cascading effect on
later stages of processing. The review that appears in the chapter dedicated to the
tactile perception in this volume does not seem to support this position. It could also
to think that the particular physical characteristics of braille were responsible for
the low reading rate observed. But again, we find that the data
experimental results collected in that same chapter we just referred to were
obtained from perceptual presentations that use cells as stimuli
braille. Consequently, neither the perceptual speed of touch, nor the own
Characteristics of Braille can be considered responsible for the scarcity.
reading speed.
On the other hand, there are data, also tactile reading, in which the system is not used.
braille. We refer to works on reading rates using the optacon.
Remember that this device transforms the visual shape of letters into a tactile profile.
through an electronic procedure. It seems that with this device the reading rates
are still smaller than with Braille, as Bliss (1978) reports that, in the best of
cases, and after a long training program, the reading rate can reach
14.84 words per minute. The work of Hislop, Zuber, and Trimble (1983) also uses
this same device, but it simultaneously studies the effect of text complexity
about the reading rate, finding that the average reading speed is 28.2 p/m, with
medium ranges that oscillate between 17.8 and 51.8 p/m when considered together
all the texts. The effect of the complexity of the text becomes evident when it
they compare average reading rates in the easier texts with those observed in the more difficult ones
difficulties are, respectively, 34.7 and 20.8 p/m. As can be seen, the rate of
reading in these cases is still lower than that found in studies on reading
braille. Whether this is due to the greater complexity of the figures that it offers.
option, or to the greater or lesser skill of the subjects in the use of this device or in the
Braille is something that does not allow us to deduce the studies we have. What it is
It is true that both reading systems share sequentiality as a
common characteristic.
Therefore, the hypothesis of sequentiality is the one that appears to be the most
Plausible. But, are there experimental data that clearly support it?
Fortunately, it is so and, in addition, using different sensory modalities to the
touch.
Haber and Nathanson (1969) conducted an experiment in which the subjects had to
remember groups of letters that were presented visually one by one in a
tachistoscope systematically varying the interval time between presentations,
finding that when the duration of the interstimulus interval was below
at a certain limit recovery errors began to occur. Apparently, the
the presentation of a new letter caused interference with the recording and storage of
the previous letter.

Aaranson (1968) finds the same phenomenon in the auditory modality. His subjects
they had to remember groups of digits presented sequentially, also manipulating them
the interstimulus interval. Recovery errors appeared again as these
intervals were reduced and can be explained for the same reason as in the
previous experiment.
If indeed the slowness in reading Braille is due to the presentation
necessarily sequential of each letter, then, the clairvoyants if they were reduced to
this condition would present similar reading rates. This was exactly what
they tried to do Foulke and Smith (1973) using a kind of tube, one of which
extremes, whose amplitude allowed observing a little more than one letter, could slide over
a backlit text while the subject looked from the other end with one eye
having the vision of the other obscured. Under these conditions, the subjects (students
university students) could have enough freedom to explore the part of
text that they would like, creating similar visual reading conditions,
except with regard to the sequentiality that a reader has to face
braille. According to the authors, the subjects found these conditions quite
irritants, and only a few of them lasted in the experiment long enough to
to achieve a stable reading rate in the training process. Those who
they achieved reading rates between 65 and 75 words per minute, data that
they match those offered by the literature dedicated to exploring speed of
braille reading with intermediate training, as we have already had the opportunity to
check in the review that we included above.
It seems, therefore, that the hypothesis of sequentiality has enough support.
in order to sustain themselves. So far we have seen how reducing the seers to
the conditions that, supposedly, the blind suffer their performance drops to the level of
these. But there are also studies that have examined various conditions of
recognition of letters or words in the same visual modality that can
provide data for the discussion we are having.
Working in the same visual modality, Foulke and Wirth (1973) also studied,
through the use of the tachistoscope, the times that the subjects took to identify
consistent presentations in 1 letter, or in words of 2, 3, 4, and 5 letters. The results
they showed no significant differences between the different types of presentations.
It seems, then, that vision allows for the gathering of broader units of information from...
which allows touch that must necessarily proceed letter by letter.
Troxel's work (1967) starts from the same philosophy as the one we have just reviewed,
although it also introduces tasks specifically related to reading for both sighted and
blind. The sighted subjects had to read texts under two conditions that they share among
yes, the characteristic of being presented in a mobile window (screen presentations
from a monitor), but with the experimenter being the one who manipulated the rate of presentation.
following a method of gradual time increase for each session; the first
the condition was letter by letter, while the second was word by word. In the first
In the first case, the reading rate was 19.5 p/m, while in the second it reached 108.5.
p/m. The blind subjects, all of them expert Braille readers, were required to 'read' texts.
presented in a quite peculiar way that requires some explanation.
Let's remember that a braille typewriter has six keys, each of which
it must be pressed to write a point of the braille cell; a braille letter remains
business when the keys corresponding to the points are pressed simultaneously
they configure it. Well, the text was presented in such a way that each letter was
represented by the tactile stimulation of the fingers that should be used to write that
lyrics
using that device. In this way, the subjects were not literally reading braille,
is an analog to this system. However, its subjects, after a very brief practice,
they were able to reach a reading speed of 18 p/m, the maximum allowed by the
experimental device used. It is striking that under these conditions the
blind people would be able to match the reading rate of sighted people who used the
experimental condition letter by letter of the primitive version of the mobile window, without that,
On the other hand, it could be tested what the maximum reading rate could be.
blind in these conditions.
Ultimately, and as Foulke (1982) indicates, it seems that clairvoyants "read
not faster because they identify the same units at a higher speed, but
because they identify larger units that provide a greater amount of
information at a speed approximately similar" (p. 1"96).
In summary, although there are some outlier data for very fast braille readers whose
realizations challenge the explanations provided by the overwhelming majority of the
experimental literature that we have managed, it seems that indeed braille reading
it is much slower, even in the best of cases, than visual reading when it
It is carried out by expert readers. It gives the impression that there is an absolute limit to the
reading speed that can be achieved in Braille. However, it may be possible to
the case that some subjects are able to develop action strategies
that allow them to improve their performance in these tasks, or perhaps this is due to a
overtraining reader, something that is not controlled in any of the studies
what we know. Let's think that a sighted university reader has conducted an amount
enormous readings when reaching adulthood; however, it is difficult
check if a blind person with the same characteristics has completed a certain amount
equivalent of readings using braille, or at least a very important part of them
they have been carried out through alternative means (tape recorders or readings in
loud voice by another person). In that case, the comparison between people of similar age and
educational level can mask a significant difference in level of use and
reader overtraining. Therefore, we believe this is a topic that requires further
research.

4. Instruments and methods for the evaluation, teaching, and assistance in reading
 the visually impaired

4.1. The teaching of Braille literacy

As we have had the opportunity to verify, the first steps of the training
in Braille reading and writing are difficult for those who undertake it. When a child or
blind adults starting to read, must overcome an important obstacle, the
demotivation, since the braille system is, especially in these early moments,
not very attractive and complex.
A blind child can be easily familiarized from a very early age with
the written materials. Today we have a multitude of materials (such as stories,
comics, coloring books...) that thanks to their color, drawings, and presentation
they manage to make the child feel attracted to them. With the help of the person who
is responsible for instructing them, they are guided to awaken their curiosity about what
"they want to say" the letters that are printed, for example, when he reads a story to them
the time they observe the drawings. So it is gradually being achieved,
that the practice of reading is a conscious goal in order to obtain information, and,
As a result, a clear motivation to learn and shape his skills awakens in him.
reading skills.
Unfortunately, these facilities are not available when it comes to familiarizing and encouraging the
blind child towards reading. In the first place, there are not many materials on the market
appropriate for the beginning of reading for blind people. Secondly, we have
that we face the limitations of the sensory system they use to read: touch.
It is difficult to create written materials in braille that are as tactilely appealing as they are.
in sight for sighted children. That is, the attraction produced by color and the
drawings (that represent the content of the text) are not obtained in the same way in the
braille texts, manipulating for example the textures (adding materials to the sheet
with different textures). On the other hand, it is easy to recognize that the amount of
visual information that surrounds and even incites the curiosity of the seeing pre-reader, is not
comparable to the limited scope of stimulation towards tactile reading that a child
blind is found in his daily life.
One of the most important educational problems posed by the initiation to the
reading in visually impaired children is the decision-making about the type of system
of reading most appropriate to the perceptual-cognitive characteristics of each person.
Let's remember that, as we saw in the first chapter, the majority population of
people with visual problems are those who have some visual residue, that is,
with appropriate optical aids can perceive printed letters and, of course, signs.
tactile
of Braille. It should also be noted that during the normal initiation period to the
reading, between the ages of 6 to 8, there may be serious problems in being able to evaluate with
effectiveness the degree of useful vision that these children have due to the difficulties they face
to accurately manifest how far they are able to see. If to all these facts
we add the additional problem that, at times, the loss of vision is gradual
Due to a degenerative problem, we will clearly understand the difficulties in making a decision.
for the teaching of one type or another of reading.
As Koening and Holbrook (1989) point out, until now there has been a tendency to teach braille to
all subjects with visual impairment, regardless of their remaining vision. Nowadays
starts to rethink this position. The previous authors indicate that it is necessary
follow a process composed of two phases, an initial diagnostic phase that will provide the
indicators of the most appropriate reading medium and, a second phase of monitoring, for
control the subject's evolution, and that will allow for the most modifications
suitable for achieving good academic performance. In any case, it seems
convenient that decisions about the type of reading that should be taught to a
students with visual impairment, must be taken by multiprofessional teams,
taking into account individual needs and sensory abilities and
cognitive aspects of each person.
We should not reduce this type of decision to just two alternatives: braille and the
visual reading; there may be a third one that consists of starting by learning the system
braille through vision, to later generalize its use by the system
tactile. In this sense, a series of works, such as those by Newman et al. (1982),
Hunstad (1985) and Ochaíta et al. (1988) point out that the learning conditions
Braille visual is significantly faster and more efficient than those that use
exclusively the haptic route. The vision guides the tactile exploration of the configurations
of points, helps identify Braille patterns, and also provides a framework of
Euclidean reference that avoids spatial disorientation. Even if one learns to read.
through the Braille system, first visually produces a significant transfer to
tactile mode, so that subsequent learning is facilitated through touch.
It seems advisable, then, that people with some visual remnant and who run the
risk of losing it should use this perceptual modality whenever possible
possible. In addition to what has been said, empirical research also recommends that the
haptic teaching of Braille should start with larger cells than usual, since
it has been found that when reading with enlarged cell sizes, the difference
the difference between tactile and visual learning is not so great (Newman et al. 1982, 1985).
All these aspects (the use of Braille with larger cells of the
normals, the use of the visual remainder, if it exists, and the use of materials
significant), they must also be taken into account in the development of programs
individualized Braille teaching for adults (Yule, 1990).
On the other hand, it would be a mistake to try to teach braille reading based solely on the
translation to this system of the methods and books initially designed for the
training of sighted children. It is essential to make adaptations and changes in
the content and instructional methodology typically used with the sighted.
Throughout this chapter, we have seen a series of peculiarities of braille that
difference between visual reading and, at times, create specific difficulties for
learning. For example, given the frequent occurrence of reading errors in words
that contain letters with an especially conflicting dot configuration,
it is advisable to keep this fact in mind to place greater emphasis on this type of
problems throughout the instruction. Let us remember in this regard, as an example, the
confusions that appear in words with letters of related spatial shapes or
rotated (df-j-h, n-z-é, e-i, á-u and ó-u), or the differences in notation between the vowels
accented and unaccented, etc.. The works dedicated to training in the
character recognition (Umsted, 1970, Krueger and Ward, 1983) have been revealed
effective against these problems, by achieving an increase in reading speed and a
decrease in the number of reading errors. A more general sample on how
addressing the specific needs of braille teaching can be found in the
Mangold Development Program of Tactile Perception and Braille Letter Recognition
(Mangold, 1977), or in the "Pattems" (Caton, Rankin, 1980, Caton, Pester, and Bradley,
1982), and an attempt to initiate a more systematic method of teaching in
Braille Spanish is the set of materials with the generic designation of
Thyme (Lucerga, 1990).
But when it comes to planning a reading instruction program, it is not enough to have in
it is important to assess and intervene, if applicable, regarding aspects of the reading process.
in another series of factors or operations, such as those reported by Lucerga
(1990) and Yule (1990): the internalization of the body schema; motor skills
fine and coarse, such as bimanual coordination, digital independence, movement
of the dolls, etc.; the development of tactile sensitivity; the recognition of
textures, shapes, etc.; the possibility of organizing ideas according to spatial criteria
temporary; the linguistic level, such as appropriate vocabulary for their age,
the correct pronunciation, expression, and verbal comprehension; motivation in the face of
learning; auditory skills in order to differentiate sounds and rhythms, and the level
General development. The importance of linguistic skills has been emphasized by
other authors like Swenson (1988). According to this author, it is necessary to enhance
the connection between oral language, reading, and writing in blind children already from the
Preschool. One of the first and most important tasks is to make aware of
these children of the purpose of reading and writing, their usefulness as a tool of
learning and communication. The identification of characters and their integration must not
is the ultimate goal of reading instruction, but what is important is that the subject
interrelate language, reading, and writing as meaningful instruments for
proactive activities.

4.2. Reading Assessment

There are few tests in the market to evaluate different aspects of reading in the
blind people, moreover, where they are most abundant is for the English language, so
they need a more or less extensive adaptation to make them extensible to
Castellano. Hall, Scholl and Swallow (1986) point out some of the tests developed or
adapted for English-speaking blind readers that we review below.

Instrument

Tactile Discrimination Test

Mangold Program for the Development of Tactile Perception and Letter Recognition
Braille - Test Criteno
"Reading Preparation Program for Visually Impaired Children."
Do1ch Word Card

Braille Code Recognition Test

"Durrell Listening-Reading Series"
Wide-ranging performance test
Sequential Cooperation Test for Educational Registration

Objective

Tactile discrimination

Tactile discrimination and letter recognition

Pre-reading and reading concepts

Global word recognition
Recognition of Braille code
Hearing and reading levels

Reading and orthographic levels

Reading and hearing levels

Place where it is published

American Printing House for the Blind

Exceptional Teaching Aids

American Printing House for the Blind

American Printing House for the Blind

American Printing House for the Blind
American Printing House for the Blind
American Printing House for the Blind

National Association for the Visually Impaired

Other tests that may be useful are the 'Braille Reading Speed Test and
Pepper Visual Skills for Reading Test by Baldasare, Watson, Whittaker, and Miller
Shaffer (1986) who evaluate the visual components of the reading processes of the
people with visual rest
The most comprehensive battery in Spanish for the evaluation of reading in individuals
Blind is the one carried out by our team and has not been published. 1. This battery is
composed of a set of tests that aim to evaluate the following areas:
segmentation skills; reading letters, syllables, words, phrases, and texts;
reading comprehension of words, phrases, and texts; and comprehensive memory. These same
areas are taken into account to assess writing.

4.3. Technical aids for the reading of the blind and visually impaired

As we have seen throughout this chapter, one of the clearest consequences of

the difficulties faced by braille readers is reading speed
slower than that of sighted readers. This slowness in reading can have little
importance in the development of daily activities or in the reading that is carried out by
pleasure, but when reading is done for educational or professional purposes,
its impact can be considerable. In this way, blind students have
certain disadvantages in their academic performance compared to sighted students in their
same level.
The materials developed to promote and enhance both reading and
writing of blind people has undergone great evolution, from the earliest
optical aids (magnifying lenses and telescopes), through the already classic assistance of the
the only factor that would always end the healing is the injections. However,
new data was necessary to discover the necessary factors for healing that
it could be produced through two distinct combinations: injections and pills or
injections and diet. Thus, the test was designed to uncover the two mistakes of
inference that is most commonly made: false inclusion (including the pills
because they are present in the treatment of the two cured patients) and the false
exclusion (excluding diet and exercise without considering that there may be effects
due to the interaction of the factors). If the subject said they needed more data, they were given
it informed that I could request the corresponding results from the experimenter
treatments based on all the combinations of factors that I wanted. Then the
the experimenter provided the dishes corresponding to the required factors,
as well as the result obtained with these. When the subject said to be sure of the
the curative treatment should be communicated to the experimenter and explained why it
It was considered this way. The analysis criteria used for clairvoyants were followed in the
research by Pozo (1985 and 1987).
The results obtained in the first part of the test showed that there was a clear
progress in the use of more appropriate causal inferences as it increased the
age of the subjects. First of all, the two lowest age levels used strategies
of reasoning based on their personal ideas, without taking into account the information that
they had about cured and uncured patients. Adolescents and adults, due to the
On the contrary, they were capable of using that information when solving the task. But
Important progress was also found in adolescent reasoning.
adults and adults regarding the group of 14 years: the latter resolved
predominantly the task based solely on one of the four cases presented,
whereas the former used all the available data in their reasoning.
In addition, younger adolescents used inclusion inferences (accepting the
the incidence of a factor on the outcome), and they were not able to use the exclusion one
(eliminate the impact of a factor on the outcome). On the contrary, the two levels of
adults made the same number of inferences of one type and another. If we compare
these results with those obtained by Pozo (1985 and 1987) in sighted subjects, all
seems to indicate that the evolution of the blind and visually impaired throughout the
different age levels is very similar to that of the seers. Moreover, the data
allow us to assert that the strategies used by the visually impaired are of the same type as
the ones from the seers.
It should be noted, however, that in the second part of the test there do seem to exist
differences in reasoning between our visually impaired subjects and the sighted
studied by Pozo in 1985. The number of blind and amblyopic individuals who completed this
The second part was smaller than that of the seers. These results are difficult to achieve.
explainable and, undoubtedly, require further research to determine if they are
caused by the conditions of the test application or if, on the contrary, there are
real differences between the reasoning of the blind and the sighted. It is very likely that the
the tendency of blind and visually impaired individuals to 'close' the task prematurely may
must, again, be due to the characteristics of tactile perception. Undoubtedly, it would have to
result in being slower and more cumbersome for our subjects to obtain the information about the
different treatments and their results through touch that for sighted people when taking
visually the information. In any case, the comparison between blind and sighted people.
it can only be considered approximate. As stated in section 3.2 of this same
chapter, the school and family conditions more than the visual problems, can
explain the differences between blind people and sighted people. Thus, it should be taken into account that the
As the reader may suppose, it is practically impossible to provide within the framework of this
book a complete and updated overview of all existing instruments in the
market. However, a guide that can illustrate the variety of electronic aids
existing has been developed by Leventhal, Schreier, De Witt, and Myers (1988). Also
the work of De Witt, Schreier, Leventhal, and Meyers (1988) can be illustrative as they
they review six software/hardware products (DP-ll/Plus, Large Print DOS, Lyon Large
Print, Vista/Vista2, Zoom Text, PC Lens) for visually impaired subjects, which allows
work interactively with most application programs
market IT professionals with the support of D.O.S.. On the other hand, Leventhal, Schreier
Uslan (1990) presents a comparative study of four other electronic aids.
braille (Alva Braille Terminal, Braille X m-80, Key-Braill y Navigator). These works
they do not limit themselves to only offering, for each of these aids, the technical indications, the
controls and commands with which they are equipped, but also review their
possibilities of use and learning.

5. Summary and discussion: Are the processes of visual reading identical?

and those of the touch? "

Throughout this chapter, we have covered the most important aspects.

about what has been researched within the field of reading psychology in the
blind people. In this section, we will attempt to summarize the most relevant points of what
as exposed, as well as to examine some of the existing differences between visual reading
and tactile reading, in order for the reader to have an overview of this topic.
As we pointed out in the initial sections, reading is a complex activity that
includes a series of processes, from the purely perceptual and most basic, to the
of higher order that involve the construction of a mental model of the text, and
whose result is the understanding of a written text. Both the blind and the
readers, with the appropriate reading skills, are able to extract the meaning of
a text, but what are the reading processes necessary to achieve that understanding?
the same in visual reading as in tactile reading?
The reading processes of sighted and blind individuals from the same culture cannot be equated.
completely, since they present important differences right from the beginning
moments of the reading activity. We can consider that braille reading of the
Blind people have a task different from that of sighted individuals reading texts.
printed in ink. Evidently, there are aspects that are common to both types of
reading (influence of word familiarity, variation in reading speed in
function of the complexity of the text, etc.), but differences also appear
important due mainly to limitations of the sensory mediator with
that collects the information, the touch. Perhaps what most characterizes the reading of the
blind people regarding the sighted, it is not so much the processing that is done of the
perceived information, but the moment prior to this processing. The origin of the
the differences between one and the other would be mainly in the different quantity of
information that can be collected in a single tactile fixation (in the case of the blind) in
comparison to what encompasses a single visual fixation (in the case of sighted individuals); it is
to say, one of the keys would lie in the different perceptual fields that are
available by touch and by the
view. As a consequence of this, the rest of the processes involved in reading
they vary, as do the development pathways of those same processes.
If we now turn to look at the cognitive functions included in reading activity,
we can notice that some distinguishing peculiarities appear from the
character encoding of written characters. Just like in the seers, we find within
from this process a series of stages in the evolution of reading skill since
their instruction begins until they become a skilled reader, but their development and
the functioning in blind people is not exactly equivalent to that of the
first. At first, the blind child (or the adult) focuses exclusively on
the tactile exploration of the points that appear in the braille cells identifies the
distances between points, their spatial relationship, then they identify patterns of points in
function of its vertical and horizontal addresses, so that slowly
they are recognizing point configurations, distinguishing one from another. In the seer
this type of perceptual learning is fully acquired before facing the
reading.
In the next stage, the child begins to relate the configurations of points with
the names or sounds that correspond to them, being able to read words thanks to the
phonological coding, that is, through the assembly of its stored sounds
in a memory retention, which remains activated through a review strategy,
thus being able to identify the word and its meaning stored in memory.
But a word is not always recognized following the previous process, the blind person
can read in a faster and more comfortable way. Specifically, when the
reading skills are optimal, the printed material in braille is in good condition, the
words that appear are familiar and/or there is an appropriate force with the textual, the reader
blind can use a 'faster' access route to the lexicon that we could call
as 'indirect-inferential route' or 'inferential route'. But it is necessary to specify that this
"faster access to the lexicon" is not exactly the same as direct access to the lexicon of the
sightseers. Only when a good skill has been acquired in the previous stage, will you ...
automate the most basic decoding processes, allowing readers to
identify known words more quickly, just by recognizing their characters
initials, without the need to do a phonological coding of the whole word. But.
this last stage can only be acquired when the blind person has good skill
reader. In the studies conducted with subjects of different age levels and
reading skill (Ochaíta et al. 1988) has been proven that blind people, in general,
they do not achieve this last type of skill until adolescence (provided that the beginning
that reading instruction has started at the right age). This automation
allows the reader to have a greater number of attentional resources to integrate the
information presented in the text and construct its meaning. .
This type of reading to which they are subjected due to their perceptual peculiarities
blind people can be similar to what a sighted person would be forced to do if they
we present a fragmented text letter by letter through the 'window' procedure
mobile." That is to say, if I were only able to appreciate one letter in each blow of sight and the
reference of the length of the remaining letters of each word. In this case the reader
the clairvoyant should keep in their memory all the letters that appear in form
successive, to integrate them (through phonological coding and even through access
indirect-inferential) in order to recognize the word in question. The result
it would probably be a slow read, and at first painful, which would be relieved by the
development of lexical encoding strategies, as indeed happens to readers
braille.

Furthermore, if the hypothesis formulated by Grunwald could be verified, to which I referred earlier
we have referenced, expert readers can take a step further in development
of reading strategies. Specifically, this author pointed out the possibility that some
braille readers carry out their reading process through, not through a sequential process
as the one we have been describing, but through the recognition of the "melody
"tactile" that each word offers. Although this hypothesis currently lacks
experimental support that allows it to be sustained, we do not think it is a
crazy proposal. She would allow explaining the high reading rates observed in
some blind readers and it would necessarily imply the existence of a more accessible
quick to the lexicon. In any case, we reiterate the need to delve deeper into the
investigation of this issue.
On the other hand, there remains a whole area of study within the reading of people.
blind people on which not much work has been done, and which involves the
interaction between basic decoding processes and higher-order processes, we
we are referring to the influence of context on the recognition of braille words.
The work carried out seems to indicate that there is an effect in blind reading.
significant of the semantic facilitation given by the context in reading conditions
normal braille, but this effect disappears when the legibility of the braille is reduced
due to the degradation of the points. This is because attentional resources must
to dedicate oneself almost exclusively to the most basic processes such as the analysis of the
features of Braille characters. When this occurs, the context cannot be attended to.
correctly, and consequently semantic facilitation does not occur. This situation
contrasts with that of the seers, in which the influence of the semantic context in the
Word recognition increases as the readability of printed text decreases.
(Stanovich, 1981). But it should not be forgotten that Braille already in normal conditions
presents greater readability difficulties than printed text in ink, which is why the
Braille degradation has effects of greater magnitude than letter degradation.
in ink due to which the effects on the processing that is carried out
the ends will also be different.
An aspect that has received great attention within reading studies
Braille has been the reading speed. The reading speed in braille is much lower.
to that of visual reading, and this rate progresses very slowly as age increases
and the reading instruction. Except for a few exceptions, adults can achieve a
reading speed that ranges around 100-120 words per minute. It seems that
they can hardly reach a reading rate approaching 150 words per
minute.
But what determines the time it takes to read a word? For
to answer this question, let us remember the distinction made by Nolan and Kederis of a
"coverage time" (the time it takes for a subject to traverse and identify a...
word) and a "synthetic time" (sum of the recognition times of each one of
the letters that make up a word). If we consider that the time of identification
of a word includes the time needed to perceive each letter, along with the
necessary to integrate the previously stored information and thereby identify a
complete word, we are saying that, in general, the 'coverage time' is greater
that the 'synthetic time', which is the case that actually occurs in tactile reading.
But this "coverage time" is reduced when the subject reads very words
relatives, where it is able to infer the final characters of the word by identifying
only the first letters. This process will be favored under conditions of assistance
contextual and will allow reducing the reading time of a word, thus increasing
so, the reading speed.
Furthermore, we have seen that there is a direct relationship between exploration patterns.
manual and the reading speed of blind subjects. The more skilled readers
they usually use both hands in their reading, with each one acting more
independent as their reading skill is superior. However, other factors,
as the complexity of the text can affect the modes of exploration making them
return to more primitive movement patterns.
It seems clear that speed can be increased through training programs.
reader, either through the implementation of information gathering strategies
situated in the text or through the manipulation of motivational and social variables
that some studies have shown as relevant. In the few programs of
training carried out, it seems that the subjects with lower reading skills are the ones that
more take advantage of this training. In any case, they are missed
jobs that aim to train the types of manual movements that are more
efficient for increasing reading speed.
Any type of comparison between the data obtained in experimental work with
blind and sighted people can be seen as nuanced if we take into account that it is difficult
equalize the level of reading usage in both populations. We have already pointed out that the
Blind people tend to make very little use of braille literacy. Therefore, we believe
It is very difficult to affirm that they have reached the level of overtraining.
a reader who manages to reach a cultured clairvoyant. We are not asserting that this is
impossible, but we try to draw attention to the difficulty of controlling this
variable in empirical studies, since, although it is not difficult to establish the skill
For a reader, it is not so much about controlling daily use as it is about it for a period of time.
has made it very prolonged. Perhaps, some of the limitations of reading
Braille observed in adults is largely attributable to this factor. But, again,
We must point out the lack of empirical evidence in this regard.
As can be verified, the same psychological function, reading in this case,
requires different processes to be carried out when the resources
the subject's are different from those offered by the norm. Following the theoretical approach
outlined by Vygotsky and Luria, we could say that functional systems
"artificial" structures that need to be built to achieve reading skills are different in
blind and sighted people, since the 'natural' systems they start from are different and
This leads to different stages of development. Therefore, we do not believe that it has any
it makes sense to try to narrow the possible differences, as it is about processes in good
very different parts and involve different structures. However, that does not mean
to say that we should not try to improve the education systems or take advantage of all the
possible alternatives that technological development may offer.
We would not want to conclude without once again drawing the reader's attention to some
characteristics of the Braille system, and review some of the gaps in research
psychological about reading using this notation system.
In the previous pages, we have pointed out a multitude of inconveniences that it presents.
braille reading when compared to alphabetical visual reading. Obviously,
the reader will wonder why blind people do not choose in the face of these difficulties
other more effective means of information transmission that lack these problems,
how magnetic tapes, computers, etc. are today, in fact,
the use of these technical means is beginning to be enhanced. However, it is
It is important to emphasize the usefulness of Braille despite all the problems that
it entails. As pointed out by Mangolg and Mangold (1989) and Ciccone (1990), it is advisable to do
making blind people aware of the usefulness of braille for their social functioning
in general, as the other alternative systems do not cover all the needs of the
blind subjects in their daily functioning. Perhaps one of the reasons why the
Braille reading method hardly finds competitors among the other systems,
either for the range of functions it fulfills as a printed procedure similar to
those used by the clairvoyants.
As we have repeatedly pointed out, the psychology of reading of the
Blind people is still a little-studied field. The research conducted is
very punctual and scattered and, even, there are a great number of aspects little or nothing
studied. Specifically, there is a significant experimental gap regarding one of the aspects
most important of reading, comprehension. Also missed are jobs
about the development of reading skills and instructional processes that include
issues such as the development of metalinguistic skills.
Another area where the lack of studies is almost absolute is that of
relationships between hand movements and reading strategies, and the issue of the possible
the existence of a tactile memory seal. Perhaps this aspect requires the development of
a relatively complex apparatus, which allows for the comparative study of the
hand movements in the blind and the eye movements in the seeing. Another
a different and perhaps simpler possibility for studying this issue is to make progress in the
study with clairvoyants whose perceptual field is reduced to similar situations
like the blind, how can it be to subject them to reading tasks with a window
mobile letter by letter. .
On the other hand, it is still advisable to delve into aspects of the process.
readers are more studied than those of access to the lexicon. We believe that the hypothesis of
Grunwald deserves to be explored in depth; this might shed light
about the outlier data of subjects with high reading rates. Finally, the possible
relationships between letter recognition problems that are observed at the beginning of
the school instruction of Braille reading, and the peculiarities of the development of the
geometric and spatial notions that are observed in the same evolutionary periods,
we believe they are also deserving of work that explores them.
Chapter 7
PSYCHOLOGY OF BLINDNESS AND GENERAL PSYCHOLOGY

ALBERTO ROSA, JUAN ANTONIO HUERTAS and FLORENTINO BLANCO

1. Objectives of the chapter: metatheory and theory

The intention of this chapter is to provide a general compilation and interpretation of

the information gathered in the previous chapters. In short, it would be about going back to
examine, but now in light of the data from the review already conducted, the question with the
that we started this volume. That is to say, whether the existence of a
psychology of blindness.
We will approach this attempt following the next structure. First, we will present
What is the metatheoretical position we assume when making the interpretation?
from the information we have gathered. Next; we will discuss an interpretation
from this data within the framework in which we find ourselves. Finally, we will make a
general reflection on the significance of these events, both from the point of view
theoretical as well as practical, adding, at the same time, some considerations
methodological.
Before delving definitively into the matter, allow us a brief explanation about the
the way we are going to approach the content of this chapter and its relationship with the rest
from the book. As the informed reader will have noticed, each chapter has been

built with a double bias, on one hand, the one imposed by the empirical material that
provides the available literature on each studied topic and, on the other hand, the particular
theoretical preference of each author or group of authors, this last aspect, which is not in
absolute independent of the previous one. This may lead to the idea that the point of
view of the group that compiles this volume is debated in an eclecticism between
theoretical stances that are very difficult to reconcile. This objection is not entirely unjustified,
As the content of the preceding chapters makes clear, however, the
as authors, we understand this eclecticism not as a state, but as a process that
tends towards the construction of a general point of view that allows for the explanation of the
empirical findings offered by empirical studies conducted from theoretical perspectives
very different. A process that moves between the tension of the data that it offers the
literature and the philosophical stance of the authors. Precisely one of the objectives of this
the chapter is to explore the path towards that broader perspective.
This objective that we have just expressed, in order to be addressed with any possibility
of success, requires the assistance of some methodological concepts that we are going to
allow to examine subsequently.
First, let's differentiate between the theoretical and metatheoretical levels. The theoretical level
is one that addresses specific areas of reality, constructing data, creating
scientific facts based on concrete rules of action about the studied phenomena
(cf. Hübner, 1983; Latour, 1987). That is, the data and, even more, categories
Complete psychological assessments are artifacts created from concrete theories when applied.
about empirical reality. This is the case with concepts such as perception,
representation, memory, or development, to name just a few. This plane
theoretical, for its part, and like empirical data, does not have a
autonomous existence, but rather is derived from another theory of a more general scope and that
in this case, it does not deal directly with empirical reality, but with theories and with the
Images of the world that these theories offer. We call this plane metatheoretical.
Another way to refer to this metatheoretical plane is to call it a 'paradigm' (Kuhn, 1962),
"research program" (Lakatos, 1970), or "general psychology" (Vygotsky,
1982b), among other possible names. This metatheoretical plan determines the type
of theories that describe reality, and therefore, create certain conditions of
possibility for the construction of empirical data.
In other words, if we consider that scientific theories are systems of rules that
they specify the behavior of the part of reality they refer to, the metatheory,
then, it would be the set of rules to which the construction of theories conforms and the
set of rules that regulate the relationship between various theories. In this sense, the
considering a metatheoretical framework when examining empirical reality is not a luxury
unnecessary, but an essential methodological requirement for progress in the
understanding of reality (cf. Vygotsky, 1982b).
The various chapters of this volume have focused on the study of aspects
concrete (tactile perception, reading, spatial knowledge, development) and for that
They have examined data constructed from very heterogeneous theories. Our
intention, now, is to expose the viewpoint we adopt, thus creating
dimensions of tension between the metatheory we defend and the concrete theories that
They provide data, and this is intended to highlight pathways for future work. By
consequently, we do not intend here to offer alternatives for each of the areas that
we study, but rather, precisely, to highlight some of the inconsistencies
existing and some requirements that future theoretical developments must meet that
accept the position that we defend here and that they want to explain the empirical data that
here it has been managed.
The perspective we advocate is not something we are now going to propose as a
added to what has been presented so far in this volume, as in various
chapters have elaborated on some concepts that are revisited here. Nevertheless,
nowhere has an attempt been made to offer a global perspective that encompasses the diverse
discussed aspects. That is precisely the attempt we are undertaking.

2. What model of psychological subject do we handle? Towards the development of a

metatheoretical point of view

2.1. Methodological Assumptions

Before starting the presentation of what our metatheoretical stance is, it seems to us
it is pertinent to recall now some of the requirements that we considered a must meet
theoretical approach to the psychology of blindness, and that of individuals with deficiencies
in general, which we already mentioned in chapter 1 of this volume and which can be summarized
in the following manner.

Some postulates

1. The subjects affected by deficiencies have the same psychic apparatus and the same
principles of development that the rest of the subjects of the species. The differences
initials with the subjects referred to as 'normal' must be describable in
biological terms, although other terms may arise during development
differences that can be placed at very different levels and whose etiology cannot be
to attribute solely and mechanically and directly to the initial biological difference.
2. Adopt a constructivist perspective but not fatalistic or rigidly.
deterministic, in the sense that development is the result of an interaction between
innate aspects and experience with the environment. But neither the path of development, nor the
the limits of this are predetermined, although constrained by both factors of
subject as of the environment.
3. The units of analysis and the explanatory principles that are used for each level
the analyses must be coherent with each other. Specifically, the following are considered
levels of analysis: biological, computational, psychological, and social.
4. The differences that appear regarding the subjects called normal (and between the
own subjects with deficiencies) must be explained from the resources that the
metatheory and the different theories that develop it. The use of "ad" principles
this means, not applicable to the general population, is not acceptable.
5. Methodologically adopt the position of the weakest. In this case, be able to
to explain the phenomena studied from the subjective experience and the position of the
subjects with special needs, from what they have, not from what they lack. And that
with a central objective: to help improve the quality of life of the subjects studied. It is
to say, to tend to a psychology at the service of the subjects, not of the researchers.
The reasons supporting the adoption of these postulates have already been, to a large extent,
exposed in the first chapter, so we will not insist on them again.
In the following pages, we will only elaborate on the aspects that were not addressed then.

Levels of analysis

Previously, we referred to the existence of various levels of analysis that we judged.

It is relevant to consider regarding the explanation we intend to offer.
These levels of analysis partly coincide with disciplinary boundaries, but we believe that
it is of interest to mention them, as the distinction between them will be useful to us later.
utility.
The biological level is not specifically the object of our study, since the
phenomena that we intend to explain do not fall within its domain, however, the
the population we are referring to - the blind - is defined precisely by a
biological characteristic: the sensory systems of relationship with the world. On the other hand
part, precisely the biological characteristics of the subject, both in their development through
of the vital cycle, like the various successive states of its general bodily structure, and
especially neurological, pose a set of restrictions that cannot be overlooked
to be considered for the study we are undertaking. At the time of our presentation we
we are going to limit ourselves to referring to some restrictions that are applicable to others
levels of analysis based on the data available from the disciplines that
they study the human biological basis.
The computational level refers to the structure of the operations performed by the device.
human psyche based on the biological support it has. It is a level
dedicated to analyzing the formal structure of the tasks that the subject performs and that can
it could also be subdivided into other levels of analysis (cf. Marr, 1982). It would not be about
return to the study of the syntax of some supposed symbols stored in the mind,
but remains at a subconceptual level (Smolensky, 1988) constituted by
units
simple connected within a complex network that activates in action. This level of
analysis serves as the interface between the biological level and the psychic level,
aiming to explain the transition from a biological apparatus to a
psychic apparatus. Note that this level is constrained by the properties of the apparatus
biological that supports it, while at the same time, imposes restrictions on the actions that
they can be carried out from each of the others. At the same time, the levels
superiors provide the occasions, along with the contents and a good part of the
structures, for their operation in real situations.
The psychological level refers to individual actions. Actions at the same time
external and internal, objective and subjective, are the result of the functioning of a
biological structure with certain computational properties and partially
responsible for the construction and modification of that structure. However, the
actions are not displayed immediately, as an empirical phenomenon, but rather
they are a methodological artifact. Later we will delve deeper into the concepts.
related to this level of analysis. The social level marks the conditions under which it can
to carry out the manifest behavior, the demands for action, and the aids for it.
It also includes social relationships, communication, cultural constructs, the
institutional conditions, etc. That is, the set of frameworks of action in which
the individual lives and in which he develops his behavior.
From our point of view, all these levels of analysis are nothing more than different
facets of a single entity: the human subject who is a biological organism that acts
in a physical, social, and cultural environment. If one distinguishes between the levels of analysis that
we have presented above is with the intention of facilitating the study of that reality so
complex, constituting different objects of study and applying methodologies to them
developed from different scientific practices, each with its own tradition.
Therefore, each level of analysis focuses on a particular aspect of the subject.
The structure of the considered levels leads to the operations that occur in
Each level poses a set of restrictions on the possibilities of the immediately preceding one.
super organized, while they are the actions produced at the suprordinate level
who put into action the potentialities of action that each subordinate level
It contains. In short, it is maintained that functions depend on structures.
but these last ones are transformed through action. It is precisely this
conception that forces us to adopt a dynamic and genetic point of view in our
approximation.
Each level of analysis constitutes the field of work of one or more disciplines.
the field of psychology, which is what interests us here, is, for historical reasons that
here we are not going to explore, between the two central levels considered (computational and
psychological). However, both the biological and social levels prove to be
essential for psychological explanation, although for very different reasons. The
biological level to explain the possibilities and restrictions that the infrastructure
the physics of your body offers to the individual; and the social level, because it shows us the context
and the conditions in which the subject must conduct themselves. Both levels of analysis
they are essential to explain the action, as they precisely mark the boundary
of the psychological with other levels of reality, so that it is precisely to
starting from the relationship with the part of reality studied by these two levels of analysis
like the
Psychology is relevant to people.
If we postulate the presence of these levels of analysis, we must also move forward.
What are the units of analysis and the explanatory principles to be applied in each case.
We are not going to pretend to expose all these aspects in a systematic way.
exhaustive, as it would force us to enter the realm of others
disciplines drifting away from the objective of this chapter; we will limit ourselves to exposing
those extremes that are essential for the argument we want
to support.
We maintain that all levels of analysis have an isomorphic structure, although
the units and explanatory principles of each level can be very different, although
they must be compatible and coherent with each other. The isomorphic structure to which we
we refer to it as the "functional system". As noted by the "Laboratory of
Comparative Human Cognition" (1982), we see no reason why the idea of
Luria's functional system should be restricted solely to the biological level; just as
here we present it expands towards the computational level (cf. McClelland, Rumelhart)
and Hinton, 1986), the psychological (Vygotsky, 1982a; Luria, 1932) and the social (LCHD,
1982). This isomorphic structure has a systemic nature and is the result of the
simultaneous collaboration of various pre-existing subsystems for the
realization of a concrete action. The consideration of this isomorphic structure gives us
It will allow us to distinguish at each level of analysis which are the subsystems.
concretes that constitute the functional system in that case, and the explanatory principles
of its functioning. But that is something that goes beyond the metatheoretical level to enter
in the field of specific theories that develop concrete aspects of each level of
analysis or relate one level of analysis to another. And that is something we will go
presenting throughout the following exhibition as it progresses
I need it for our argumentation.

2.2. A genetic perspective

We start from the idea that any explanation of a phenomenon must include its
genesis. This implies the inclusion of the temporal dimension in psychological study
to explain not only how behavior evolves over time, but how it
they transform the mechanisms that make it possible.
Likewise, we assume that the human psychological subject is the result of a process of
self-construction based on the action of the subject contextualized in a concrete environment.
To this end, it resorts to the action mechanisms available at the moment.
that begins their life, like those others that can be incorporated through their relationship
with the environment. This way of understanding development has been conceptualized in a very
various ways. The image we are now going to present aims to offer a perspective
global of how we understand it at the metatheoretical level in which we operate.
To do this, we will focus on the psychological level first to,
subsequently, extend the argument to the other levels considered.

Development as the construction of functional action systems

Vygotsky (1982a) proposed that the history of development is the history of construction
of psychological systems, understanding them as the composition of functions
"innate" naturals to form other new ones, which, according to him, have a nature
"artificial," as they are the result of historically developed modes of action in the
breasts of cultural groups. These new artificial systems are understood as the
result of the composition of natural systems produced through mechanisms
of mediation, in whose nature we will stop later. As is known,
Luria took up this concept of "psychological systems" (which had already been indicated by)
other authors like Hughlings-Jackson, Head, or Anokhin) and from that he developed the idea
of the brain's 'functional systems'. The latter would be the instantiation
neuronal of interaction with the environment and, consequently, the infrastructure that it
Nervous activity supplies for psychological functioning. This infrastructure
part of a natural raw material (pre-programmed modules) and offers a product
elaborate result of the interaction of the subject with the physical and social environment (systems
functional results of the collaboration of various modules for the realization of a
certain action). But let's pause briefly, based on the authors that
we just mentioned, in the presentation of the different types of systems that can
to consider oneself.
First of all, natural systems. These are, as we have just said, part
of the initial resources that biology offers to the psychological functioning of the subject
and that unfold throughout the biological maturation of the organism. They are
constituted by pre-existing brain interconnection systems that sustain
functions that are already available from the moment of birth and that are put into
march in response to environmental stimulation. They can also appear at times
subsequent development as a consequence of maturation. This interpretation that
what we have just done is consistent not only with the contributions of Soviet authors
that we have cited, but also from contributions much closer in time

1 For a discussion on the concept of 'function' and on the notion of 'system'

functional" see Luria (1969).
(End of note 1).

(cf. Rumelhart & McClelland, 1986, pp. 139-142). In very brief form, it could
it is considered that these natural systems rely on brain modules
independent ones that operate massively in parallel containing information
innate distributed in its structure and activated upon the presentation of certain
type of environmental stimuli. Secondly, one can speak of systems
combined, the product of the composition of natural systems as a consequence
of the organism's activity in its relationships with the environment. They come to be the
result of a learning process through which the organism learns patterns of action
adjusted to the needs of the relationship with the environment. This learning establishes
new connections, or modify the previous ones and allow the range of behaviors to
greatly expanded and consequently providing great flexibility to the possibilities
of the organism's action. It should be noted that this combination of functions implies
coordination of natural systems (e.g. sensory-motor coordination). These
combined systems, therefore, are the result of simultaneous activation and
coordination of two modules (or several groups of modules) for the implementation of a
action in the environment. It should be noted that, so far, no differences have been established.
among the systems that animals have and those that are more characteristic
humans. The forms of animal learning studied in the laboratory, and which can
occurring in humans as well, would be cases that can be integrated within this category.
The third type of psychological systems are the specifically artificial, cultural.
They are basically similar in structure to the combined ones, although they include a
peculiarity that is what allows them to be differentiated. These are systems in which the
the composition of natural functions is established through mechanisms of
mediation, which require the use of external means that allow for
relationship the initial systems that compose them. Those external means are artifacts
cultural (tools or instruments of mediation), being among the most
important those that have a semiotic nature such as the case of signs that
they convey the meanings on which the linguistic message is articulated. The
higher psychological functions (memory, attention, intellectual skills, etc.) are
they would be profoundly transformed with the contribution of the original instruments
cultural and would not have a specific cerebral localization, given that for their implementation
walking requires the activity of very large areas of the brain; those in which
the natural systems that are associated to produce these are situated here
we are referring to, along with broad unspecified areas of association.
As can be verified, this notion of psychological systems (psychological level)
it is compatible with that of Luria's functional systems (1969) (biological level)
and also with the notion of schema at the computational level (cf. Rumelhart,
Smolensky, McClelland, and Hinton, 1986), although, for this latter case, it is advisable that
let's make some clarifications.
Let us remember that for the last cited authors (cf. Rumelhart, McClelland and the
PDP Group, 1986), knowledge is not something that is stored in an analog manner,
but is manifested through the simultaneous activation of networks of units
of distributed processing. From this point of view, we do not see that there is any
inconvenient to consider that the "schemas," as conceived by these authors
(that is, as a pattern of distribution of activation and inhibition weights in networks
neural networks) are not limited only to the "representation" of objects or situations, but rather
include, also a "representation" of forms of action. We put in quotes the
word representation to highlight that it is a way of storing
knowledge, but it is neither implemented in an analog way nor is it present in
some type of 'mind' contemplated as a repository of symbolic representations.
On the contrary, it is a state of the neural networks that when activated for an action
it can produce, then yes, a conscious representation that can appear in a
certain sensory modality and manage to collaborate in guiding one's own actions.
In this way, individual skills could be conceptualized as schemes.
acquired through action. These schemes would then correspond to the
structure of the functional systems and they would be modified and expanded over time.
development as experience becomes enriched through new exchanges
with the environment.
It is interesting to gather some of the statements made by Rumelhart, Smolensky, and others.
(1986) refer to human computational possibilities. According to them,
human animals are very efficient at pattern matching, in the
anticipation of the outcome of actions, and in the manipulation of the environment.
Precisely this last aspect, which includes the manipulation of tools, is what
what distinguishes man from animals, allowing him to think logically and
to build
a culture. The human subject needs to solve complex problems
to have serial resolution procedures through their specific manipulation
and external. In other words, the ability to solve complex problems demands
break the problem into several steps that can be solved with the
limited processing capabilities that are available. And, in addition, each step
requires manipulation (or operation) with an object (or a representation of that
object) to solve that fraction of the problem. Precisely what is most difficult
it is to devise those procedures for breaking down problems, that's why the groups
cultural practices carefully preserve and transmit the new procedures devised
for that. That is to say, it seems as if each human subject had certain capabilities
limited but, throughout the social history of their group, they have been developing
new problem-solving systems that are increasingly sophisticated (with more steps of
mediation), which each individual subject must learn throughout history of
his life (p. 44 and following).
2.3. The mediated action

Given the importance that, from this point of view, mediated action takes, we need
of a theoretical exam about how the process by which it is produced works. This is a
favorite study topic by theorists working from the perspective
socio-historical in psychology (cf. Vygotsky, 1978; Luria, 1932; Wertsch, 1985, 1991).
We do not have space here to develop this concept in depth,
so we will limit ourselves to making a brief presentation, leaving it to the reader
interested in delving into this topic through the resource that the references represent
that have just been supplied.
In brief words. These authors argue that human action on the
the world is not exercised directly through the direct action of the subject on the
objects, but rather requires the use of artifacts developed by cultures over time
of its historical development. These artifacts (mediation instruments) allow
perform certain operations and not others due to their particular characteristics (e.g., the
The physical structure of a hammer makes it more useful for striking than for painting.
unlike a brush). The subject, during the training they undergo within
From their social group, they learn to perform operations with these objects, they learn to handle them,
and, in this way, acquires skills of action. We would say that the instrument allows
act on the environment by modifying it, but at the same time, the instrument modifies
the subject. It is a complex process of skill building in which
they use instruments of very different kinds, from physical tools to symbols, and
that merges, like in an alloy, with the processes of maturation and enculturation,
well, these action systems on the environment become, neurologically,
functional systems, and at the psychological level in action skills. Vygotsky, when referring to
the process of skill building talks about what he calls the 'law of double
"formation" (1978), according to which every operation that the subject learns to perform does so
first in a manifest, external way, in the course of a social activity, and then the
internalize it, turning it into an internal skill that can become automated.
However, the concept of mediated action, although central to the considerations
that we are carrying out here (cf. Wertsch, 1991), needs to be specified within the
conceptual framework that we are outlining here.
Previously, we mentioned that solving complex problems requires action.
the measure that is first manifest, in observable external behavior, and then can
to internalize, becoming part of the subject's repertoire of skills,
making itself present in the consciousness and then, very often, arriving at
to automate itself without the need for correlates to be present
phenomenal conscious. In other words, behavior towards the environment forces to
collaborate with different functional systems, creating others that are the result of
the composition of the previous ones, and whose activation and operation is going to
automating with the exercise.
In this way, external bodily action, the observable manifest behavior, ends in
part inhibiting itself, as its functionality is disappearing, since in its origin
it served to make different functional systems work in parallel by acting on a
external mediating object. When the new functional system (or the new skill,
using different terminology it is already created, we can say that this new
knowledge is preserved in the form of schemes (understood as a state of
activation of neural networks, not as a symbolic representation on a plane
metaphorical called "mind"). These schemes would then be activated when
necessary results for the execution of an action and, at times, this activation
it provokes the emergence of consciousness phenomena.
But the concept of mediation contains great explanatory richness. Allow us
examine some of its possibilities.

Mediation in action

If every action is necessarily mediated, let us focus on the various types of

mediation 2 that we can consider from a broad interpretation of this concept.
First, we will consider the mediation of the organism-environment interfaces,
that is, the sensory receptor systems and the motor apparatus that allow
interact with the environment. These interfaces produce relevant experience for the
organism, allowing it to represent the world in a certain way through forms
of actions that enable and, consequently, the type of information they collect. Of
this way they measure the entirety of the experience by making the environment present through
of bodily action, both on the behavioral level and in all the other ones that are attached to it
subordinate. Let us note that depending on the type and condition of these interfaces the
objects have different "affordances". It can be said that these interfaces are the
mediation instruments at the biological level.
Secondly, we will consider instrumental mediation in the strict sense. It is about
of the instrumental artifacts created or acquired by the cultural group for the
implementation of actions on the environment. Normally these devices have been
designed to be used by normal people (without any deficiencies), so that
when there is an adaptation to meet any of the special needs of individuals
"deficient" one must consider the possibility that the use of these instruments
adapted can make the structure of the tasks to be performed by both types of
subjects may be different. In other words, the operations to be performed (in the sense of
term
operation as used by Leontiev, 1978) do not have to be exactly equivalent
to those of normal individuals. E.g., the use of braille or different forms of written notation.
for reading in contrast to the use of the Roman alphabetical system.
A third form of mediation to distinguish is semiotic mediation that uses as
mediation instrument various instruments that allow the transmission of meanings
(from natural language to artificial languages). Speech is primarily a
instrument for communication that, in its origin, is a means for the 'regulation of
behavior of others. Studies like those of Vygotsky (1934) or Luria (1979a)
they have highlighted how from that role of external regulation of the
2 The initial consideration that the Moscow school made of the mediation instrument
it was restricted to the use of tools, that is, to the use of cultural artifacts
developed within the group over a historical evolution (Cf. Leontiev,
1931; Luria, 1932; Vygotski, 1930). However, soon Vygotski himself understood
that this concept included a greater virtuality than that restricted to objects
with a physical materiality. The idea of semiotic mediation is a result of the
expansion of the notion of mediation instrument from a physical object to a sign,
that is neither less material nor instrumental (Luria, 1932; Vygotsky, 1934), but whose
character of 'tool' is starting to seem more metaphorical than literal. Today the
the concept of mediation receives an even broader interpretation; e.g. Wertsch (1991)
talks about 'mediational resources (mediational means),' to refer to everything
that an individual mobilizes when executing an action.
3 "Affordance" is a neologism created by James Gibson from the English verb "to
afford that results in very difficult translation. García Albea (1986) translated it to
Spanish as 'functional properties'. 'To afford', according to the dictionary of
Collins (1971) means "to provide", "to give opportunity", "to allow" among others
meanings. In any case, this expression always includes the idea of a subject who
through its action it apprehends what the object allows to be done with that form of
action. We have preferred to keep the English expression of this neologism instead of
to venture a translation.
(End of notes 2 and 3).

behavior by another becomes egocentric speech. first, and then internal.

that serves for the regulation of the subject's own activity, finally reaching
become an instrument of thought allowing it to carry out a set of
functions that without their assistance would be impossible. The functions of language are varied,
and we cannot now elaborate on them, what we do want to point out here is their
function as the creation of meaning and the elaboration of concepts, both in what is
refers to the things of the external world as to the subject's own self-concept. If the
the concept of objects is acquired through a complex process of action and
regulation - socially mediated - of the action on the object, the self-concept itself
it is achieved through the modes of action of one on the world and the messages
regulators and declaratives that others emit about one’s performance.
But, in addition, there is another type of mediation for individual action that, in turn,
time is social and instrumental. We refer to the social mediation that can take
various ways. The simplest of them is the use of another person as an instrument.
of mediation for action on the environment. This is an absolutely phenomenon
everyday (e.g. when at the table - we ask someone to fill a glass of water for us),
and that has tremendous importance in development. Riviere and Coll (1985) have highlighted
it is evident how the attributions that adults make about the intentionality of
the child's behaviors lead to actions being taken by the adults of
which, sooner or later, the child ends up building actions
communicative in which the germ of meaning is already present. In this way, a behavior
physics ends up, through social scaffolding, becoming a symbolic action and
intentional. Among the action guidelines that are implemented during this period are the
to indicate or request, from which protodeclaratives and protoimperatives arise.
Precisely in these cases, the subject's action on the environment is not exercised.
directly, but through the action of another. A human adult acts, literally,
as an instrument of mediation for a child's action on the environment. This way
of action that, as we have seen, endures throughout life in cooperation
interpersonal, relying on the verbal regulation of the behavior of some people
on the part of others, it may play a quite different role in the case of subjects
with serious impacts. It is common to observe how adults, or siblings, or
companions, act as mediators in the necessary interactions with the environment
of a subject with a physical deficiency, through both verbal regulations of the
behavior of those by this one, as well as communication guidelines developed at
through coexistence. In this way, a social form of mediation for action
concrete leads to semiotic mediation, an extremely...
powerful.
An example of the phenomenon we just described, among the many that could
to put on, it would be that of the wandering of a blind person with the help of a sighted guide. That
a person literally acts as a mediation instrument to relate to the
environment, but at the same time, it can help regulate behavior through emissions
verbal, teaching the blind orientation strategies, etc. The use of a guide dog
it also involves using a biological organism as an interface for the relationship with
the environment, but, in this case the forms of interaction are very different, and not
One can speak of a semiotic mediation as in the previous case.
But there is a much stronger sense of this social mediation, it refers to the way in
the primordial social groups to which the subject belongs (family,
community, etc.) integrate that individual into the social practices of the group. But for
to be able to explore this form of mediation in some detail, it is necessary to delve deeper
previously in the notion of action and in the structure of activity.

Action and structure of the activity

Let's remember that previously we pointed out, when we referred to the various levels of
analysis that we considered, that the subordinates posed restrictions to the
superordinate, but it was these last ones who put some of the
potentials of the previous ones. In order to explore the implications of this
affirmation we will now follow a downward strategy in our presentation. For
Hello, we will start from the social level of analysis descending, from there, to each of
the previous ones.
Social groups develop a set of practices through which they organize
their relationship with the environment and structure the relationships among their members. The
members of that group need to know how to carry out those practices, because
what over time has developed a set of activities
institutionalized specialized in acquiring the precise skills for
to be able to join the group's practices.
Leontiev (1978) has developed a set of concepts that are useful to us here.
utility, especially when studying the structure of the activity. This author
distinguishes between three distinct concepts (activity, action, and operation) that we are going to
reinterpret, including them within the general framework that we have been developing.
The first of the concepts that Leontiev (op. cit.) offers is that of activity. This lays out the
we understand here as the individual facet of social practice. While we can
consider that the group engages in 'social practices', the individual incorporates into them
through the execution of concrete activities (e.g.: working, studying, going to class,
writing, etc.). Therefore, all activity has a social character and is motivated, it is
to say, there is a specific reason that motivates her, although, at times, this reason may
not being present in consciousness (e.g.: making money, climbing socially, learning,
to communicate, to ask for something, to thank for attention, etc.). Ultimately, behavior
human is not responsive, but teleological, seeking the satisfaction of a motive, the
most of the time not reducible to purely biological needs, but rather a result of
the needs of the social organization itself. It can be said that in order to join
In carrying out social activities, one must adopt, in one way or another, some
the social reasons that justify the performance of such activity.
But the concept of activity, as it has already been pointed out, serves as the interface between the
part of the level of social analysis that would be the object of study of other social sciences
(the practices) and that other part that interests the psychologist. Its consideration is
important, both because it establishes that bridge between the social and the individual, as
because it includes within itself a concept of great importance when it comes to explaining the
human behavior: motivation, a concept that requires detailed examination in
the one we will stop at later.
On the other hand, carrying out these social activities requires having a
set of skills. Society has created a set of instruments for this purpose.
(e.g. paper and pencils), practices (e.g. formal instruction) and institutions (e.g. the
schools) dedicated precisely to this purpose. Through them, skills are taught.
action, the patterns of social relationships, values, attitudes, etc., and are transmitted
the social reasons. It must be taken into account that both in the instruction for the
the implementation of social practices, as in any other form of activity, is
where social relations between the individual and the group are established.
The action refers to that manifest part of the activity that aims to
achievement of a goal. While the activity is triggered by a reason, the action is
aims at a specific goal. A useful way to understand this distinction is to consider that
the activity, as we noted earlier, is the individual facet of a social practice,
while actions are the different phases of carrying out behaviors
concrete actions that lead to achieving partial goals related to the reason that
energizes the activity. In this sense, the actions come to be the specification
Functional of an activity; a global activity is concretized and specified in phases.
directed towards a goal. This does not exclude activities that include a single action.
For example, teaching is a social practice that takes place in the institution.
school. A teacher carries out their work, their activity there, but this can be analyzed from
various ways depending on the dominant motivation present at a moment
different, for she will be the one to bring forth the meaning of that activity for that individual
concrete and that will be manifested in a concrete way. The teacher works to
earn money, but work to teach, teach because you consider it a moral duty, or
simply as a way to make a living like any other.
The concrete actions I develop will vary depending on what their motive is.
simply earn a salary, or produce a change for the better in the student. Both
things are true, the teacher is a worker and a facilitator, but the representation
what makes its activity, the hierarchization it makes of the motives that energize it, and
the meaning of the activity they find is extremely important to understand
What is he/she doing?
Within the framework that we uphold here, both activity and action occur in
the social plan, since both lack meaning outside the context that justifies them.
Note that both action and activity are fundamentally functional concepts,
well, they express the completion of phases of a process aimed at a specific goal. Although
Actions are necessarily mediated and always take place in contexts.
concrete, at the level of analysis of the activity or the action the concrete way in which it
structuring the task for the individual does not seem relevant. We could say that for
To carry out their teaching activity, a teacher needs to read a manual to master a
concrete technique (e.g. an operating system manual for a computer); the latter is
a concrete action, and at this level of analysis it is irrelevant whether that manual is
written in Braille or in Roman alphabet, as long as that person has the
precise resources to effectively read it, for what really matters, to this
level, is to obtain the necessary information to use a command that, in turn,
will allow to carry out another thing that is instrumental for the activity being developed.
When we descend into the more concrete realm of what the subject actually is
it is being conducted effectively behaviorally we encounter another concept of
Leontiev (op. cit.) is useful to us. The operations refer to the conditions.
concrete actions executed in the specific context in which they are carried out. It is
to say, if we consider that the action to be carried out is specified in a specific task to
perform with some concrete mediational instruments, the operation is what a subject
concrete is made with specific instruments in a specific situation. Let's think that
the same action can materialize in very disparate operations when it is carried out in
cable in different situations and/or by different subjects. The operation therefore is something
which, by definition, is carried out by a specific individual, but its own definition seems
to restrict this concept to develop without any conative type element,
intentional or motivational; something that seems more typical of a psychology of the
behavior that comes from the action. An example of operation would be the sequence of movements.
and strategies implemented by a blind person to move from one place to another,
but without taking into account, e.g., feelings of anxiety, insecurity, doubts, fears,
powerlessness, pleasure, fulfillment of a desire, etc. that may influence development
of that activity.
It is this consideration that we have just made that leads us to consider that the unit
of psychological level analysis, following Wertsch (1991), is the action performed with
mediation instruments. That is to say, adapting it to Leontiev's terminology that
we have just referred to, the specific operation that the subject performs, but including in it
the intentional aspects that guide it and its function within the activity to which
belongs.
Returning to the consideration of the four levels of analysis that we have been handling,
we could say that the action performed by a subject included within an activity,
it can be considered as the result of the activation of a subsymbolic scheme (such as
as we have been understanding it here) which, in turn, is nothing more than the properties
computational of the activation of a functional brain system. In any case,
It should be taken into account that the activation of these schemes only makes sense.
for the subject, and 'meaning' for an observer, if accompanied by a
emotional correlation and an intention, for the subject, and a social function, for the
observer. This functional consideration of 'action' avoids the artificial divorce between
knowledge and emotion, between the psychological and the social, which then would not be shown
as separate entities, but as facets of a single united process.
Ultimately, the incorporation into social practices ends up building one's own.
functional structure of the psychic and cerebral systems of the subject. If we pay attention
now in the case of individuals with physical and sensory disabilities, we can give ourselves
account that the mediational interfaces with the environment are not the same as the
what the generality of the population disposes, this poses certain restrictions to them
particular for their incorporation into social activities, as the actions that the
components can have a very different operational structure (for their specific case) than
the one that has for a subject who has all the interfaces intact. This does not mean
to say that the person affected by a deficiency cannot perform that action, but rather
the mediation instruments that must be used for this can have to be
different in some cases. That is to say, having distinct components that, at times,
require a particular sequencing of their composition. In other words, a
the same action (e.g. paying with coins) within a social activity
a determined action (e.g. going shopping) can have a very different operational structure in
the case of a blind person and a sighted person. But, however, the only way in which
the brain systems on which the
schemes that allow carrying out the operations that lead to delivering a certain
The amount of money to the store clerk is, precisely, being trained in
that specific skill, integrating into that type of social activity, going shopping
many times, making mistakes and internalizing, learning the procedures
operational, with or without formal training, with less or more effort. That is,
although the operational structure may be different, the acquisition procedure, to
at a macroscopic level, it is the same as in the case of normal subjects; but, without
embargo, when we focus on the specific components of the operations to be carried out, we
we found ourselves with a different structure. In other words, under a homogeneity
functional underlies a structural heterogeneity. But this final homogeneity that
appears as a result of a complex learning process that may have followed a
a developmental path very different from that of normal subjects, precisely
because the formal requirements of the tasks to be performed can be very different when
the mediational instruments available are different.

The issue of heterogeneity

We have previously pointed out that the sensory and motor apparatus of the human body are
interfaces for the relationship with the external world and, in addition, that could also be
considered as instruments of mediation for perceptual and motor action
regarding the objects in the environment. In this second case, they would not be instruments.
of mediation of a historic-cultural nature, but biological-evolutionary. But this
the distinction we just made becomes more meaningful when we apply it to the
characterization of development in terms of the construction of psychological systems,
especially if we refer to individuals with severe physical disabilities.
What happens when one of these interfaces is seriously damaged? The answer
it will undoubtedly depend on which of them it is, as the function of each one of them
it is very specific and affects development in a very particular way. However, there would be
some common elements that we will develop below. First, we
we would encounter the lack of some natural functions, but if these are not
absolutely essential for survival in the environment in which the
the individual lives, the consequences are not fatal. The organism must interact with the
environment with the rest of its systems intact and, from them, build the systems
combined relationships with the environment. For example, a blind person from birth will not be able to
build visual-manual coordinations, but this does not imply that I will not carry out
sensorimotor coordinations, will carry out oral-manual coordinations or
audiomanuals that, evidently, do not have exactly the same purpose as the
first, but that fulfill a functional role for development not very different. This
brings consequences, for example, for the development of the notion of object that does not
produced at the same moment in the blind as in the sighted, but ultimately arrives at
reach it, and is perfectly capable of ultimately becoming an adult with the same
intellectual abilities that a seer has, even at the current stage of development
technology cannot be a pilot. In short, in cases where we ...
We have been using the combined systems that are established, in some cases fulfilling
functions similar to those performed in the case of subjects without deficiencies, but in
others, taking charge, through new connections, of functions they do not perform in
the case of subjects who have all their interfaces of interaction with the environment.
In any case, it should be remembered that intact functions do not hypertrophy, their
sensorial and action thresholds are biologically limited, what varies is the
interfunctional connection.
In the case of cultural origin systems that give rise to psychological functions
higher up the situation becomes more complex. Now it's about learning strategies of
mediated actions on the world and to attribute meanings to it and to behaviors
in it, at the same time as systems of motivation, affect, self-concept, etc. If in the
in the case of normal children, we find a very high dependency
of the environment in relation to these issues, the case of individuals with serious
deficiencies are even more delicate. We have already pointed out at the beginning of this chapter
how the development of technological mediation instruments, along with techniques of
specific instructions can make these subjects functionally become
equivalents to the normals. But, we can also encounter cases where,
along with the sensory deprivation that comes with having one of those interfaces damaged
relationship with the environment, a social and cultural deprivation occurs. In these cases
we would encounter devastating effects on development that could not be
not solely attributed to the deficiency, but to the failure to implement the resources
that in all the
cases facilitate human development and, in the case of individuals with deficiencies,
they offer the conditions of possibility to functionally remedy them to the extent that
the possible.
We find, then, that in cases of physically and sensorially deficient subjects not
the assumption of the 'normal development pattern' is applicable, at least in principle,
the rest of the children although, however, in the end, and if the available resources have been
used properly, an equivalent result in development can be achieved
intellectual. However, the general principles of development are identical for all
the cases. The question would be, then, to explore what the peculiarities are that it takes
the development of each of these deficiencies in the conditions of our culture, already
that we have indicated are the instruments and the procedures of action used
the responsible parties for the emergence of higher psychological processes.

2.4. Development as a sequential process. The Zone of Proximal Development

But the heterogeneity in the structure of the schemes of individuals with deficiencies
in relation to those called normals, it should not, as we have already pointed out,
obscure the existing homogeneity in the concrete mechanisms through which
development occurs. This is always a composition of functional systems that
they are formed through learnings and, consequently, imply qualitative leaps
conceptualizable from a systemic conception, or, if you prefer to use another
language, the creation of a new system makes it have emergent properties
regarding what the previous subsystems were composed of. The creation of
a certain psychological system implies that its previous components of level
inferior are previously established, which makes the development process
necessarily sequential, without the prior stages being able to be skipped. An adequate
task analysis will allow us to identify what the basic components are
a system and what skills should be trained before taking on a new step.
The concept of the Zone of Proximal Development (ZPD) is a methodological construct.
dedicated precisely to unraveling the development of this process. The definition
The initial part of this concept is related to the psychological evaluation of the skills of
child. According to Vygotsky, the ZPD is the distance between the existing knowledge
current issues of the child that are revealed in the performance of tasks on their own and
without assistance - the 'current development zone' (CDZ) - and what it is capable of carrying out with the
help from the examiner. This concept has subsequently received an interpretation.
much broader within the socio-historical-cultural conception that we have been
following. On one hand, the ZDP represents the realm of what the child is capable of
to learn in the immediate future, in this sense any instruction below the ZDA
does not advance the subject, but merely exercises already known skills,
while any instruction beyond the ZDP is useless, since the subject does not
has the precise elements to build that new step in development. For
another part, the ZDP is not something that 'possesses' or 'is in' the child, but rather literally
create in the process of social interaction between the child and the instructor or between a group of
children with unequal resources for task resolution. It is literally a system
external, in the social sphere, where a functional system for action is created
collective from the subsystems that provide the structure and the concrete context of
the situation and the individuals themselves who collaborate. The ZDP thus comes to represent the
creation of a social environment for the implementation of teaching activities
learning in which the learner is provided with mediation instruments and the
precise semiotic mediators for the completion of a task and, consequently, for
the acquisition of knowledge that allows the construction of new systems
psychological. In this sense, an estimation of the ZDP is extremely difficult to
establish, as it depends on the specific situation in which the collaboration is established.
Valsiner (1984) develops some concepts related to this of the ZDP, which
can you explain in more detail the development process in terms of interaction
of the subject with its environment. Let's look at the contribution that this author makes with some
detention.
According to him, the developing child acts within the structured context of a
human environment, but the child's actions transform the structure of that
context, so that its changing structure provides the child with new
action opportunities that may not have been available before. When
At the same time, the structure of the child's environment defines the set of possible
actions that the subject can perform in a given state of the environment. This is an idea
that Valsiner relates to the concept of "affordance," a neologism also for the
English language, developed by James Gibson (1979, p. 127; cited by Valsiner, 1984)
who defines it as follows: "The affordance of the environment is what it offers to the animal,
what it supplies or provides for better or for worse... What I intend to communicate is
something that refers to both the environment and the animal in a way that no other does
4) An exposition of the concept of Zone of Proximal Development from different
perspectives and possibilities of application can be found in Rogoff and Wertsch
(1984); existing term to date. It implies the complementarity of
environment and the animal." Valsiner points out that the "affordances" of situations
specific, and of objects in specific situations, define the limits of actions
in principle possible for the child. In this regard, it points out that objects 'allow'
that certain actions be taken with them, but depending on the degree to which the
a child may be able to perform some actions at a moment in their development and not others. For
For example, a ladder can be climbed, but a 10-month-old child cannot do it.
although it will do so with ease at a later stage of its development. In this sense
the set of "affordances" defines the niche for the structure of the child's actions
in the environment, and the 'effectivities' are the subset of the 'affordances' that
they take action in the activity of the subject in a specific environment at a moment
concrete. But, it is important to take into account that the child's relationships with the environment
They are channeled 5 by the process of the child's interaction with other people (parents,
caregivers, siblings, teachers, etc.) in relation to an environmental setting
determined, so that the function of the child-adult interaction, from the
the perspective of the explanation of development lies in the regulation of relationships
child-environment. It is from this perspective that it begins for the elaborations on the
the concept of ZDP that we mentioned earlier. Let's see it in his own words.
Within the field of objects, and the 'affordances' related to them, in the
child's environment, the Free Movement Zone (ZML) is defined by the
children's activities. The ZML structures the child's access to different areas in the
environment, to different objects within these areas, and to different ways of acting
about these objects. The limits of the ZML are the situations in which the ZML is
it reinstates or redefines. The concept of ZML has its roots in field theory of
Lewin (1933,
1.939). The ZML is a changing structure of the child-adult relationship.
that channels (marks the limits, but does not rigidly determine) the development of the
actions of the child in the expected directions in a given culture. The ZML is a
cognitive structure built socially for child-environment relationships. It is
socially constructed because it is based on the system of meanings of the
adult members of the culture and because it is the result of the child-adult interaction. It is
a cognitive structure because it organizes the child-environment relationships on the basis of
beliefs and

Valsiner (1987) clarifies the applicability of the channeling concept for psychology.
of development. The concept of canalization was introduced in the biology of development.
by Waddington (1942, 1966, 1968, 1970) as a way of relating the
genotype with the phenotype. The basic idea is that the interaction of the genome with the
environment produces conditions that create pathways for change, a kind of
valleys (the creodes) in an epigenetic landscape through which development would flow. In this
meaning, development is directed towards the adult state through a system of
restrictions that largely leave the concrete future of development uncertain
each individual, but it does allow predicting the main direction of development based on
of the restrictions that constitute the channeling system. According to Valsiner (op. cit.) the
the application of Waddington's concept to developmental psychology would require
some modifications. First, the restrictions that occur in the process
the processes of socialization do not have a permanent nature throughout development, but rather
the system of adult-child-environment interactions is changing and, moreover, varies in
function of the motives and purposes of the participants. On the other hand, the actions of the
the child is made to participate in their own development through the modification of the
structural restrictions that surround him. In Valsiner's own words (1987):
"Channeling, as the general mechanism of action and cognitive development of
child, it is a gradual process in which the previous child-environment structures guide the
subsequent development of the child in the direction of new structures that, in turn,
channel their subsequent progress." (p.85).
(End of note 5).

meanings used by members of the culture in their activities. Finally, and in

against the widespread tendency to project cognitive phenomena onto the "mind" of a
small child, the cognitive structure here is a structure of relationships between the
children's actions and the "affordances" of objects. The central thesis of the present
The theoretical framework is that effectiveness emerges in the child's actions as a
result of the process of social construction mediated by the ZML.
The ZML is an inhibitory mechanism. Its function is to limit the function of actions.
of the child in a particular structured environment. Within the ZML it is possible.
specify subzones - that further organize the relationships between child and environment. These zones
- Promoted Action Zones (ZAP) - are sub-areas of the ZML in which the
child caregivers try to promote certain actions with particular objects. The child
he can, but does not need to, respond to these efforts of the adult. If the child does not respond,
it is not necessary that any restriction or limiting action follows from it by
adult. This contrasts with the adult's behavior when the child crosses the boundaries of
the ZML and the adult acts to restore or redefine their boundaries." (Valsiner,
1.984, pp. 67-68
The ZML and the ZAP are, therefore, mechanisms that selectively regulate the degrees of
freedom of children's actions in the environment and can be related to
the concept of ZDP. Let's see, in Valsiner's own words, how it is possible
establish this relationship.
The ZDP is very related to the ZAP. It can, but does not need to, overlap totally or
partially with her. Parents can try to promote certain patterns of action
of the child at a moment when the history of development has not yet prepared him
for that. In this case, the ZAP and the ZDP do not overlap. Parents can also
propose action patterns at a time when the child is beginning to be able to
develop them in cooperation with the adult (the ZAP overlaps with the ZPD); later the
the child will be able to perform these actions individually. Or, the parents may decide
not to promote and not to allow a certain activity that the child, otherwise, could have.
carry out with the help of others. In this case, the ZDP falls outside the ZLM. If the limit of
the ZLM is not redefined to include the set of actions in the ZDP, then the
parenting socialization strategies eliminate the possibility that the child
develop skills in these possible actions, but not put into practice.
importance of these theoretical developments by Valsiner when applied to the
the developmental psychology of children with deficiencies cannot escape us, because
from them we can conceptualize some aspects of their development that
we consider it interesting to include here.
First of all, it should be noted that the 'affordances' of objects are not the
the same when the subject has some possibilities of action over it as when some
Its interfaces of interaction with the environment are damaged. Let's remember that for
James Gibson (1979, pp. 127-8), the 'affordances of an object are relative to
of the animal that acts upon it. Eleanor Gibson (1988, p.7) also notes that the
"Affordances" of things must be learned with the help of systems.
perceptual and exploratory behavior. To this we must add something about what already
We have insisted earlier. The actions of the subjects at each moment of
development varies depending on the footprint in their physical and psychological structure.
has left the particular story of the formation of their psychological systems
secondary and cultural. Encompassing these two aspects, and using the terminology of
Valsiner would say that a specific situation with concrete objects offers
some "effectivities" of action that are not identical for normal and deficient subjects
of the same age, and even of the same evolutionary level. e.g., a 'Nintendo' does not
it enables the same actions for a blind or sighted child, just as it does not
make a cardboard sheet written in braille.
Secondly, and derived from the above, the ZML has a different dimension in
function, also, of what the damaged interface is, and, moreover, of what the attitude of the
caregivers and instructors in this regard. It is evident that the possibilities for action
the autonomy of a blind, deaf, or paralyzed child are not equivalent. But, in addition, and
As Valsiner rightly points out, the limitations to this action posed by the
adults around them set the limits of the possibilities for construction of
skills on the part of the subject. Issues such as overprotection or rejection of the
interaction with the child by leaving them in situations of physical or social isolation can
have dramatic effects. But the flip side is the possibility that
other people serve as 'interfaces' for action (motor or perceptual)
of the child with deficiency, in this case the ZML of the subject with deficiency can be expanded
to a great extent, making it possible to observe and coordinate situations and
actions that would otherwise be forbidden to him.
Thirdly, the relationship between the ZAP and the ZML can be very different in the
case of subjects with deficiencies and in normal ones. While in the latter the ZAP
Yes, as Valsiner indicates, a subarea of ZML, in the case of subjects with
physical and sensory effects the ZAP goes out of the ZML, as it results
accessible for the subject's action, performing a function similar to that of the case of the
seers, but whose importance may be proportionally much greater. Let’s think
in the case of a severely affected cerebral palsy subject; for him, his possibilities
of free action in the environment is very restricted (although by no means are
null, cf. Rosa, in press); the case of a blind person, although it is different, shares some of
these characteristics: for example, it will not be aware of the possibilities of action that
it has in a given situation until I know what objects are available,
and for that you may need help from other people. In this case, they will be the
activities promoted by the people around them, with the help of objects, the
verbal mediation, etc., which will provide you with possibilities for interaction with the
physical and social environment that would otherwise be very difficult for them to establish. In this
if the ZAP comes to play a crucial role in development, we would dare to
to say that it is this social mediation that makes others act like the interfaces
physical and sensory that they lack. In this way, and through mediation
social and symbolic, they connect them with a world of objects and meanings that
they would not be accessible to them if they only had their own resources.
Fourthly, and derived from the above, the overlaps between the three concepts that
we have been managing (ZDP, ZML, and ZAP) are, in these cases, different from what
Valsiner points out for normal subjects. The ZAP has to leave the ZML to
create Proximal Development Zones that otherwise might not reach
to establish oneself. That is, the ZAP represents an intentional framework for development. But
this does not mean that the subject can be shaped absolutely by the environment.
In any case, development continues its course, the various different skills
they must combine with each other to form psychological systems, in such a way
that the ZDP must always be taken into account for the organization of activities, since
there is a danger that the actions proposed under the belief that one is
acting appropriately fall below the ZDA or are above the ZDP.
Ultimately, the functionality of the ZAP is the same in normal and deficient.
but its importance becomes much more evident in the case of the disabled.
in the case of these subjects, their dependence on the social environment is much greater than that of the
normal ones and she will come to owe the overcoming of the limitations that for her
development implies physical or sensory deficiencies in cases where it arrives at
to produce an adequate development.
Ultimately, both the attitude of parents, caregivers, and teachers towards the child with
deficiencies, such as the establishment of goals and the application of technology
of education are crucial, as they will largely determine the possibilities
of development that these subjects have.
But what we have just said has quite broad implications, as the position that
we have presented implies that the development path is not predetermined, but rather
it depends on the channeling that the environment does for the subject's performance,
canalization that necessarily has a different shape depending on both the
social situation surrounding the subject, as well as the biological apparatus that they possess.
Let's consider that for a person with physical deficiencies, the 'affordances' of objects...
they are different from those of normal subjects. Thus, not only are the
demands of the tasks to be carried out in relation to the environment, but rather,
Furthermore, also the very structure of its schemes acquired through its
previous experience is qualitatively different.

2.5. Activity, communication, and motivation. The channeling of development

The approach we have been presenting avoids dissociating the realm of the emotional.
motivational of the cognitive, since all of this is included within the concept
general of the activity. When explaining the development of the human subject does not
we could differentiate, then, cognitive development from personality development, since the
first would only be a facet, artificially isolated, of the second. When it comes to
explaining the development should then take into account both the changes
motivations that arise with the process of biological maturation such as the
behavioral guidelines that are implemented at every moment.
Elkonin (1971) precisely develops this point. For him, throughout development...
two types of activities alternate that are distinguished by the way of addressing
environment. Firstly, those that are oriented towards the meaning of the
human activity, that is, the learning of goals, motives, and norms of the group
It will be from these activities that development in the sphere will arise.
needs and motivations). And, secondly, those through which the child
acquires the socially developed forms of action on objects and norms
about the different uses to be applied to them (note that here the object is not just a
physical element, but rather a social artifact whose use has a meaning for the
action). This distinction is certainly artificial, as in any activity these occur.
two facets, but the distinction is useful because of the emphasis placed on distinguishing between the
two aspects of social action and action with objects. Elkonin (op. cit.) elaborates
later this distinction to develop the concept of dominant activity in
each stage of development based on the changes that occur in the sphere
motivational throughout maturation, focusing on those that fulfill
a more decisive role for subsequent development. Let us consider issues such as
the need for contact with adults by babies, the coordinations
sensorimotor in the course of object games conducted both with the adult and
alone, the learning of the use of social objects (clothing, food, etc.), play
symbolic as role learning, or school work itself, as examples of
some of the reasons and forms of dominant activity throughout development.
We believe that these changes in the motivational sphere and their consequences on the
the value of incentive of different people and objects is important
fundamental for development and learning.
Precisely this aspect of the creation of social motivations, based on the foundation
biological and through incorporation into forms of social activity, it is of a
fundamental importance. From the metatheoretical perspective in which we are coming
moving there are some tools that allow us to approach the explanation of
this appearance.
On one hand, let's remember the semiotic mediation and the role it plays for the
verbal regulation of activity. According to Luria (1979), verbal emissions of the
Participants in a joint activity allow to mutually coordinate their actions.
It would precisely be the external regulation of activity in specific situations that
what would eventually produce private speech through the transition that represents the
verbal self-regulation of activity through what is known as egocentric speech (cf. also
Vygotsky, 1934.
The role of others' verbal messages is not limited to the regulation of
activity, but also allows to build a representation of the world and of the
objects that constitute it that is not limited by the accessible physical characteristics
the sensorimotor interfaces. Objects, therefore, are included within a
structured system of meanings that allows understanding of the world. And among the
objects that the subject must represent are himself, as well as the personal meaning that
it has the activities it carries out in its social sphere. In all these cases the
verbal messages received will be crucial for the formation of these concepts that, to
they also form part of their schemes of representation of the world, of themselves and of the
interaction between both. That is to say, as indicated by Valsiner (1987), a human child
it is born not only in a physically structured environment, but it is already presented to it
organized in meanings, something that is a consequence of human use of signs to
to control both the environment and oneself. It will be in this development process
how the child acquires knowledge of that environment through meanings. that
they are presented already organized, although, even from the beginning, the human subject
is active in that interaction, even being able to participate in the very dynamics
of constructing meanings.
It will be in the context of intersubjective processes of interaction that the subject
build your own system of personal senses under the guidance of others:
parents, other adult relatives, older siblings, peers, and even siblings
minors. In this way, the developing child is a collaborator in the construction of
system of cultural meanings, given that it is a target of actions
proactive and culturally organized by their caregivers. But the influence of the child in
the system of cultural meanings is not direct, but rather mediated by the
systems of personal meanings of their caregivers. On the other hand, the meanings
cultural elements are not transmitted from society to the children's parents and from them to
child in an immutable way, but rather, on the contrary, each participant in this
the process of social communication is a co-builder of cultural meanings. Thus,
parents develop their personal senses based on their
interpretation of cultural rules and expectations. The part of their systems of meaning
Personnel that is relevant to the child's development includes the organization
significant that they make of the environment of the house that the child shares, as well as their
ideas about parenting goals and practices. (...) As children develop
they are acting within these personalized environments of the parents, and acquiring
information about its meaning to
through the reactions of parents to their own actions. In this way the
children are developing their versions of the cultural system of meanings through
your social interaction with others. These versions are the result of a
construction, and do not constitute a mere copy of the systems of meaning of the
parents, but the children construct them in an innovative way on the structure of the
culturally organized information that they experience in their interaction with others
and in his exploration of the physical environment constructed by man." (Valsiner, 1987,
p.85-6).
There is a set of aspects related to the influence of the exchanged messages on the
of the social activities that it is important to consider in light of the
reflections that we have just made. But for this, we need to make an incursion into
areas related to motivational aspects that we have not yet mentioned
which, on the other hand, have a fundamental importance. To this end
we will need to resort to theories coming from metatheoretical approaches
different from what we are dealing with here, but we do not believe they will result
inconsistent with it, if we place them within the context of this specific moment of the
discussion that we have been developing. Specifically, we refer to the interpretations
that from work on the development of achievement motivation and helplessness
learned helplessness is based on the theory of attribution (cf. e.g., Abramson, Garber, and Seligman,
1980; Weiner and Litman-Adizes, 1980.
The line of research developed by the authors we have just mentioned
emphasizes the social origin and cognitive functionality of motivation, against the
tradition of considering it solely as a result of biological factors or
unconscious. From this stance, it is pointed out that human motivation is characterized by
a conscious direction towards the achievement of a defined goal
within a social environment. In this sense, Weiner and his collaborators gather a
a concept specific to social psychology, the concept of attribution, to assign to it a
fundamental role in shaping motivation. This also allows for
I manifest the relationship between the attributions that the subject makes about the causes of success.
or the failure of their own actions not only for the construction of forms of
higher motivations (for example, the motivation for achievement) but also for the
formation of self-concept and self-esteem. Wiener and Litman-Adizes (1980) point out
how the attribution of success or failure depends on a distribution of
attributions within a
three-dimensional space consisting of three axes that we will indicate next: first,
the dimension they call 'locus of causality', which refers to the attribution that the
the subject attributes the cause of the success or failure of their actions to internal factors (e.g.,
ability, mood, patience, etc.) or external (e.g., difficulty of the task, luck,
received aids, etc); second, the dimension of stability of those causes that unfolds
on a continuum between stable (invariants, e.g. skill, patience, difficulty of the
tasks, etc.) and unstable (variables, e.g. luck, effort, humor, etc.); and, third, the
dimension of controllability, which refers to whether the subject can control the factors
those who attribute that causality (e.g., effort, change of strategy, etc.), or if
these escape their control (e.g., ability, luck, difficulty of the task, etc.). From this
way, and focusing only on the most extreme cases, we would find that the
individuals who attribute success or failure to internal, variable, and controllable causes
(e.g., their effort) develops the idea that they can control the effect of their actions.
On the contrary, those who attribute the effects of their failures to internal, stable causes
and uncontrollable factors (e.g. their intelligence), and their successes to external and uncontrollable causes
(e.g., luck, or the help that someone can provide at a given moment)
they tend to develop the idea that they cannot control the effects of their behavior.
Logically, the expectations of control prompt the subject to become active in order to act.
more easily than in cases where the idea predominates that the result of the
the action to be taken becomes uncontrollable. The emotional effects of each of them
combinations of these attribution dimensions are very different, as those
causal attributions are accompanied by feelings of pride or shame in
function of whichever
the result of the action developed in relation to its estimated level of difficulty.
This brings direct consequences on the image one has of oneself and the
self-esteem. In cases where undesirable attribution effects combine with
real experiences of failure, with low self-esteem and emotional experiences
.(shame, guilt, etc.) what is known as can occur.
"learned helplessness," which leads to an inhibition of action - something like
"Whatever I do goes wrong, so it's better if I do nothing," and in the most serious cases.
situations that are no different from pathological depression. The consequences of
this situation is not limited to the construction of a poor self-concept, but rather to
through the inhibition of action, it affects learning and personal development
cognitive, affecting the construction of personality as a whole.
The causal attributions that children make about the outcomes of their behaviors do not
they do not occur to them spontaneously, but rather they take them from the verbal messages that
they receive from the significant individuals in their environment. But also, most likely
the informal ideas that adults have about psychological and developmental issues
they are not something independent of the causal attributions made about them.
behavior of the child. For example, if it is thought that intelligence is a faculty
unchangeable, that development follows a fixed and uninfluencable pattern of progress
environment and, furthermore, that organic damages produce causally direct effects
about intellectual development, then it will be difficult to undertake actions
aimed at instructing the subject in specific skills and possibly the messages
Attributive messages that are sent will have a very defined content. The free zones
Movements that are allowed would, in that case, be the only space offered to the child.
for action e, and even in the worst case, anyone can become discouraged
attempt to create action zones promoted or to launch inhibiting attributive messages
from the action. A very different picture would appear to us if those adults considered
to intelligence as something controllable and modifiable. Ultimately, the ideas that the
adults have on what the causal mechanisms of development are and of the
Learning can influence the type of tasks that are presented to them.
children, the type of support offered to them and the causal attributions of successes and
failures that adults make and that children end up internalizing. In this way
It can end up affecting intellectual development itself (cf. Palacios, González
and Moreno, 1987). All of this constitutes an example of the channeling of
development we referred to earlier, channeling that is put into action through the
activities carried out within the microculture in which the subject develops.
But, within the scenario that we have just presented, there is a factor that we do not want
stop highlighting. It is about the very structure of relationships within groups of
those of which the subject is a part, being the family, the school, or the work environment
the main ones. Within these groups, there may be relationships of dominance and
subordination that is evident in the structuring of activities and in
the messages used for its regulation. The footprint that these aspects leave on the
structuring of reality, and in the subject's own personality is also a
aspect that should not be overlooked.
If we start from the idea that the representation of reality resides in the subject in
form of schemes obtained through action, then we must agree that
these schemes include motivational, emotional aspects and meanings of style
what we just discussed. Therefore, the very operational structure of the subject includes
within itself an emotional activation resulting from the effects of its performance on the
environment and the way they act and the messages sent to them by the people who
Rodean. Hence the enormous importance of the form that social interaction takes with the
subjects with deficiencies, as they are much more dependent on it than
normal subjects.

2.6. Remediation

Previously we pointed out that the activity of human subjects on the environment is
develops through actions performed with mediational instruments. In fact
we have argued that development is based on the composition of systems of
actions on the environment mediated instrumentally or symbolically. We have also
pointing out that the resources available to individuals with disabilities are not the
same as that of normal subjects and, consequently, the history of the
development cannot be the same in both cases. However, on the other hand, it has been pointed out that
in the end, one can reach the same level of intellectual development although this is achieved in
occasions, through a process of compensation, of normally "hypertrophied" development,
in which the various psychological functions are composed in such a way that, despite the
physical disability, equivalent results are finally achieved. Lastly, there would be
It is also worth mentioning that this can be achieved through the use of technologies.
educational within institutions, such as in the case of the school, has as
function the enculturation of subjects, thus establishing a certain leveling of
skills among individuals of the same culture.
There was a period when the education of deficient subjects, or even that of the
socially marginalized and students with school failure were referred to as "education
compensatory.” This designation is now tending to disappear, however, here
we are going to try to recover it but not with the idea of opposing the concept of
"special educational needs" that we have already examined at the beginning of this
volume, but to highlight some positive aspects that we believe that old one had.
denomination. In fact, the expression in the English language that refers to education
Compensatory education is "remedial education," an education that comes to remedy deficits.
of the subject. Although we do not believe that this expression is very happy, however the
The expression remedy has a polysemy that we intend to explore. Just as Cole and
Griffin (1983) points out, "remediation means a change in the way that
mediation instruments regulate coordination with the environment" (p. 70). That is,
to remedy (to compensate, in the terminology now abandoned), is to mediate again, to mediate
in another way. Use other mediation instruments to carry out an action and that,
As we have repeatedly pointed out, it involves influencing the path of development.
This idea of remediation can already be found in the early works carried out in
collaboration by Luria and Vygotsky. Luria (1979) tells us how it is possible to remedy
a function altered by a physical impairment through a new form of
mediation, instrumental and symbolic, using conscious mechanisms, let's see it, in its
own words.
We realized the paradoxical fact that the [Parkinson's] patients, who
they could not take two consecutive steps on the ground, they could climb stairs without difficulty. We
we propose the hypothesis that when climbing a staircase, each step represented a
signal to which the patient's motor impulses responded. When climbing the stairs, the
flow of automatic and successive movements that occurs when walking on a
flat surface is replaced by a chain of separate motor reactions. In other
words, the structure of motor activity is reorganized, and a conscious response to
each link in a chain of isolated signals replaces the involuntary system
subcortically organized that guides ordinary walking.
Vygotsky used a very simple procedure to build a laboratory model
for this type of reorganization of the movement. He placed a series of paper cards
about the ground and asked the patient to step on each one of them.
Something wonderful happened. A patient who had not been able to manage by themselves more than
he marched two or three steps across the room, stepping easily on each
one of the cards as if it were climbing a staircase. We had helped the
patient to overcome the symptoms of their illness leading them to reorganize the processes
mental ones he used while walking. He had compensated for his flaw by transferring the activity
from the subcortical level where their nerves were damaged to the cortical level not
affected by the disease." (p. 128-129)
In the following paragraphs that follow the quote we just reproduced, Luria tells us
It describes how a similar procedure was used to address other motor problems.
of the Parkinsonians, but, on this occasion, resorting to symbolic mediation,
in a way that the subject was able to regain motor functionality by altering the route of the
nerve impulses through undamaged brain areas.
But it is not the same to remediate already established functional systems and then alter them.
at a later stage of development that aims to develop systems that do not yet exist
they have created; for in the first case it can be appealed to other functional systems
Similarly, results of constructions through action, but which remain
intact to neurological damage), while in the second there are no other systems.
(superior as in the case of Parkinson's) that allow to mediate the function again.
damaged.
Our intention is not to make an incursion into the neurological field now but,
resorting to the idea of isomorphism between the various levels of analysis mentioned at
At the beginning of this chapter, indicate the possibility of starting different mediation routes.
for the construction of functional systems not yet established. The Laboratory of
Comparative Human Cognition, 1982) applies this idea to
I work with students who have some learning difficulties within the framework of a model.
systemic approach for the remediation of these issues. In the words of the very own
authors:
From Luria we have adopted the notion that human interaction is virtually
always organized in functional systems, whose elements are coordinated around
the higher goals of the system. In the work for which Luria is best known in
this country [the USA] the functional systems that are considered are
those that can easily be characterized as "intrapsychological", in a way
that their work can easily be related to the interest of psychologists
North Americans on how an individual's high-level goals coordinate behavior
of that subject. Our perspective broadens this reading in two ways: one, not
there is no valid reason to exclude systems from Luria's theories
interpersonal; and, two, there are good reasons, given Luria's intellectual biography, to
consider that the zone of proximal development can be analyzed as a system
functional interpersonal. The goals included in the zones of proximal development, the
goals of the educator in an educational activity can be addressed as the goals of the
functional system. We can consider the same type of unit as the system of
child in his (more or less) independent activity and the system of joint activity
professor-child" (p.45).
The idea, ultimately, is to create practical applications based on the notions.
theories we have been managing. That is to say, establish systems of activity that
allow to train in the child the type of skills needed to achieve
functionality that you need for your performance in the world. In short, to establish
individualized curriculum adaptations that should not be limited to setting goals
different, but must serve to program activities within those systems
of relationship, that allow the student to remedy their deficiency through remediation
instrumental and social within their zone of proximal development. This implies having
previously categorized, what should be the route of its development through
task analysis procedures, within a careful specification of what has
to be the path of their development, both in early stimulation and in the
individualized curricular adaptations. We must insist that this re-
mediation does not imply going back to mediate actions that have never been carried out, but rather a
mediate the actions that the subject has to perform in a different way than how it is done: with the
normal subjects. . .

3. Ascending to the concrete. The level of specific theories within the framework of
psychology of blindness

So far we have been operating on a metatheoretical plane, a plane in which we do not

it works directly with data taken from reality, but with theories that present
a certain image of this through, in this case yes, of empirical data developed
from a certain point of view. However, that metatheoretical plane is very
useful. On one hand, because it allows to have a general idea of the subject of study that guides
the creation of working hypotheses that lead to empirical work that, in turn,
allow the creation of new theories. And, on the other hand, because it offers a space for interpretation
(or reinterpret in their case) coherently existing theories either
referred to phenomena that are restricted to only one of the levels of analysis that
we have been considering, either to relate elements belonging to
various of them.
Once we have outlined the general framework in which we operate, we are going
now let's elevate ourselves to the theoretical plane, to discuss from this perspective the most
relevant to the subjects covered in each chapter, and to point out the shortcomings that
we found in the available literature on the psychology of blindness.

3.1. Perception and subjective experience

As deduced from the postulates with which we began this chapter, a

theory of perception without vision must result derivable from a general theory of the
perception, while it can aid in the development of the latter.
Firstly, as we indicated at the beginning of the chapter dedicated to the analysis of the
perception in the blind, the major problem of any perceptual theory lies in
establish the limits of the object of that theory. In other words, where does it end
strictly biological-computational and when does the psychological begin? Or in other terms,
Where does the mere extraction of information from ambient energy end and begin?
producing knowledge? Our tentative response to the problem involves assuming that
The perceptual can be approached from the consideration of different processes.
of the global perception.
Firstly, perceiving is a process of extracting environmental information.
defined by the structural coupling of subject-object. Phylogenetic drift has endowed
to each type of specialized anatomical structures to define as
perturbations (Maturana and Varela, 1990), that is, to consider as informative,
determined states of the environment. The structures available to the subject (level
biological) are activated by those disturbances, and those forms of activation
they follow a regularity that can be modeled through a set of rules
(computational level). This allows specifying the way in which they are constituted
perceptively the objects in a common way for all members of a
species. This implies that neither the structures that make up each perceptual modality nor
the objects of the world that appear in consciousness are predefined, but rather they
they mutually constitute in the act of perception, and in a way that is determined
both in phylogeny and in ontogeny. Therefore, each mode of access to the
Information has its own rules and constitutes its own objects.
The consideration of the perceptual at this level requires, then, to take into account that each
perceptual modality puts a different world at the service of our consciousness.
From our point of view, the fact that each modality brings a phenomenology
different is not due to having to deal with different energies and, therefore, with
different regions or readings of the real, since such energetic heterogeneity
disappears at the moment it is assimilated by the same type of energy, given that
Nervous transmission always handles electrochemical energy. The differentiation
phenomenological is a consequence of the functional specialization of the different regions
cerebral through phylogenetic evolution. The course of ontogenetic development
implies, on the other hand, a progressive coordination and phenomenological differentiation of
the worlds generated by each modality.
These concise arguments, and some more that we cannot develop here, us
they allow us to assume that the initial phases of the perceptual process generate a factor of
intersubjective linking, that is, under equal conditions, all beings
humans develop in a world that is constituted, at a very basic level, with the
same rules.
What happens, then, when one of the information extraction modalities does not
Does it work? We could say, then, that individuals with sensory deficiencies have,
metaphorically speaking (see Wertsch, 1991, p. 93), a 'toolbox'
different from that which the general population has, and why
not to say it, less varied. This makes these subjects in general, and the blind in
particularly, have access to quantitatively and qualitatively different information.
Firstly, it seems clear that the amount of information, in absolute terms, of
what a blind person has is less than what is accessible to sighted people. On the other hand,
the amount of information available to a blind person in a given situation is
restricted by the spatial and temporal resolution capabilities of the modalities
available sensory modalities. The tactile modality, as we have already seen, has a capacity
of spatial resolution very different from that of the visual modality. The same happens with the
acoustic information. Ultimately, each sensory modality is specialized and, for
thus, it transports a certain type of information. This determines that the quality of
the phenomenal representation obtained is different with and without vision.
The perceptual act involves a coupling between an intentional structure -the subject- and
an aspect, physical or functional, of the object. We perceive from the object those attributes that
depends on the type of energy that the sensory interfaces used can collect
to apprehend them, which in turn makes them come determined not only by the
functional state of those interfaces, but by the intention to know. For example, the
visual or tactile perception of texture, or of temperature, depends on the action
intentional to look at or touch an object, to read the scale of a thermometer or to place
the skin in contact with the object whose temperature we intend to know; if such
Actions are not executed, those concrete understandings cannot be reached.
Perception is oriented towards a world that is becoming differentiated or segmented.
progressively throughout ontogeny. The segmentation of the world into objects or
Object configurations are not something foreign to the subject, but rather depend on their intention.
From a psychological point of view, we must assume, then, that any act
perceptive is of intentional nature, that is, it is directed at an object, which
constitutes in the same perceptual act. We must point out, however, that the intention
does not always imply an internalization of social motives. We could talk about a
"primitive intentionality" recorded in the genetic code of the species that privileges
the segmentation of certain regions of the world (for example, faces or voices
humans for babies or aerial predators for rabbits), while others
objects would be segmented through experience and learning.
It should also be noted that the different modalities of access to information
they can be ordered in relation to their ability to generate what we referred to
"attributions of externality"; that is, in relation to their ability to make us
to experience a feeling of belonging to the world. The vision, we said, is
oriented towards the world and it is difficult to find situations in which a feeling
visual is experienced as a sensation not relative to the world. Even when
we close our eyes experiencing dark gray as a quality situated outside of
us. However, the constitution of an object through touch almost implies
always a manifest intention of knowledge. Any tactile perceptual process
in the absence of vision (or when vision is not useful) implies, therefore, an exercise
from the abstraction of the subjective pole of experience in order to make inferences
about the object to be constituted. This may help to explain, at least in part, the
apparent delay of the blind compared to the sighted in the construction of a world
permanent and a differentiated self. A
the manifestation of this problem has already been reviewed in other chapters when
we talked about the persistence of the cognitive 'egocentrism' of the blind when it comes to
use resolution strategies for some tasks. On the other hand, the marked
the sequentiality of haptic perception and its nature in active underline the
the importance of intention in the configuration of objects and makes evident the
active nature of perception. This
the argument also allows for the traditional distinction between passive touch and
active touch, which would remain only as a methodological distinction.
This distinction between subjective pole and objective pole has some other consequences.
that is worth noting. First of all, it should be remembered that not everyone
senses require the same level of activity from the subject when it comes to
present information about the environment. The ear, for example, cannot be closed off from the
input of information. One cannot 'close' their ears, just as they do with the
eyes. Touch, for its part, only becomes functional through motor activation
intentionally directed and it is only through exploration that it can inform us
of aspects such as the shape of objects of a size that exceeds that of the hand.
Probably these differences that we have just pointed out between a sensory system and
others are more of a degree than all or nothing, for even in senses whose capacity of
The information collection is very high and fast, as is the vision, there is a collection.
intentionality of information, a motor action, that enables sensation.
Now moving to the objective pole, it could be considered that each object offers certain
possibilities of action - or if preferred, taking up a Gibsonian term, it has
different "affordances" - depending on how the subject can approach it. But,
In addition, each sensory modality has characteristics that are particular to it;
example, each of them has a peculiar structure of perceptual saliences (e.g. the
color in vision, texture in touch, etc.; this leads to the experience, the world
The phenomenological experience of the blind and the sighted may be very different.
In any case, the perceptual cannot be reduced to natural mechanisms of
extraction of information or constitution of the object. Perception always operates in
the breast of social activities and, therefore, is restricted or partially directed
for the meanings. The mere segmentation of perceptual reality into units
constituted (objects, events) must be mediated by the world of meanings
shared, and often for a learning experience. For example, it is very little
likely that a blind person will be able to segment in the plane a two-dimensional projection of
a three-dimensional body if a process of social mediation is not established beforehand,
of instruction regarding this.
Let's think that if objects are shown through the actions taken on them
They are carried out, these vary depending on the activities in which the subject is engaged.
included. For example, a telescope is different if one is instructed to look through it
within the function of a lookout on a ship, or if it is only used as a weapon in combat
of approach. In this sense, the incorporation into social activities will allow for
use, or at least be aware of, the possibilities of action of the objects in the world.
What we have just said takes us beyond the phenomenology of perception.
leads us to the question of the production of meanings. Something that has to do
with the incorporation into social activities, with instruction in skills
relevant to be able to execute the necessary actions. Ultimately, to access the
shared meanings in culture. We can then say that a blind person, although
he lives in a phenomenological world different from that of a seer, this does not prevent him from sharing
the same world of meanings. It is, then, already a psychological phenomenon that
It could not be explained if the level of social analysis is not taken into account.
In short, although the aesthetics of the blind may not coincide with those of the sighted,
its semantics is, as long as they share the same culture and social conditions.
The language, and especially its use within social activities, would be what
would allow remedying that situation of sensory deprivation.

3.2. Knowledge Representation

So far we have argued about the way the world...

it constitutes through the access to information mechanisms. The question is that
the results or the strategies used to access the object are preserved, that is,
form structures to be used in perceptual coupling sequences
similar, or to be put into operation for the service of new intentions.
We will call "knowledge" the set of coupling sequences.
preserved by the system and "representation" to the process by which knowledge is
brings to consciousness.
Traditionally, the analysis of representation has focused not so much on the process,
like in the final product; the characteristics of the ideas have been discussed, of their
different nature, of the format in which they were stored in a metaphorical receptacle to
what was called mind. The mind was thus reduced to its consideration as
the scenario in which the dynamics of ideas is verified; dynamics resolved in each case
for its interpretation in the light of different metaphors (mechanics, chemistry, the
hydraulics, mathematical logic, programming languages, etc.). The emergence of
a new metaphor for the analysis of the problem of knowledge - "the metaphor of
The brain" - hypothetically allows one to abandon, paraphrasing Husserl, the "prejudice of
the ideas.
We understand, then, that representation can be conceived as a process of
activation, which in its formation or in subsequent transformations generates a
structures, some action patterns for the encoding and transformation of that
information. That is, the process of representation is understood in its functioning,
in its startup in the action of the subject. This pattern of activation of units
structural is the one that provides the foundation on which they can be created or updated, in
each moment, the meanings.
There is not, then, a symbolic representation, in the sense that there is no storage.
of symbols. At the moment a subject activates a process of representation, they create or
modify a series of networks or structures to analyze and create meanings. Like
Before we progressed, this notion of representation aligns with the idea of the PDP that
Knowledge is composed of patterns of connection among multiple units.
distributed structural (García Madruga, 1992).
In this way, the representation process is based on natural systems.
of the individual. If we were to resort to our levels of analysis, the representation rests
about functional brain systems (biological level), whose activation has
certain computational properties (subsymbolic computational level),
that can be present in consciousness and have behavioral manifestations (level
psychological), while participating in a socially originated activity. It will be the function that
it fulfills that representation within the process (the action) to which it belongs, which will give it
a sense for the subject, coming to be, then, an instantiation of a meaning
social in a specific situation.
We conceive representation, then, as a process whose origin and traits
Fundamentals can be traced throughout the phylogeny of the species. It is undeniable.
that in vertebrates there is a certain process of analyzing information from a
specific environment that leads to the generation of certain meanings. A hummingbird,
for example, it is capable of recognizing, after a flight of thousands of kilometers, the
exact place where the concrete plant from where spring was released is located
previous. This means, among other things, that this activation pattern is a process
that must necessarily be intertwined in the fundamental structures of
animal.
This parsimonious explanation of representation is compatible with the tradition of
a European psychology of action, which begins to take shape with Brentano, which
coincides with the basis of the Piagetian idea of 'schema' and is similar to what
Recently, the psychologists from the PDP group have been defending.
One of the consequences of representation is the creation of meanings. But
It is worth remembering that meanings are social in their origin, they are the result of the
negotiation of the meanings that individual actions have in relation to the
reasons of the individuals who carry them out. A negotiation that is established within
social practices and through the use of mediating instruments. In other words, the
meaning is a social and psychological phenomenon, resulting from individual action in
The inner circle of a group is necessarily mediated and is the result of negotiation.
In the chapter on perception, we have seen how the use of different sensory systems
activates different functional systems and produces qualitatively conscious correlates
distinct. It can be said that each sensory system has its own units of
collection of information based on the type of actions that its anatomical structure-
functional allows you to perform with the objects. These units remain in the
representation, in the processing systems that are implemented in each
perceptual system; furthermore, both the size of those units and the way in which
the processing of information is carried out, it is what makes some modalities
they are more or less efficient in carrying out certain actions or, in other words,
the same action performed with one or another sensory modality has a structure
different operation, requiring a more or less neat processing, making it more
or less difficult and susceptible to the commission of errors. For example, it is not the same
to recognize an object visually at a glance rather than by touch,
what is required
collect data in a fragmented and sequential manner. This does not mean, in any way,
as some authors defended long ago (e.g. von Senden or Revesz) that the
blind people have great difficulties in representing the world. It is simply meant to say
that before certain tasks, means or sources of information, that the majority of the
the population primarily engages with the visual modality, the blind can show,
especially when they are poorly trained, ways to access that knowledge more
costly and elaborate. An example of these differences and difficulties can be found in
the cases of access to information written in braille or the possibilities of the blind
to develop autonomously and effectively in space.
We could say that sensory interfaces act as mediation instruments.
natural for the representation of the objects of the world. Each one of those
Instruments have a particular structure that offers certain possibilities.
and sets specific restrictions for its use. But those structural limitations do not
one could say that they restrict the subject to knowledge solely of the objects that are
they offer their sensory exploration. The semiotic mediation opens up a whole world of
possibilities of knowledge that go far beyond representation of
the concrete objects that become accessible to sensory exploration. This process,
that allows the emergence of abstract thinking, and that has an importance
fundamental for the development of every human being, reaches an importance, if applicable
even greater, in the case of the blind, as it will be through semiotic mediation that
it could come to be represented, to know, a good part of the reality that does not result to it
accessible in a sensorially direct way. And it will do so perhaps not very
different from how seers can mentally represent the 'spin' of an electron
in the Bohr atomic model or a hyperspace of 'n' dimensions.
It should be emphasized that the greatest differences in the modes of representation and
the execution of the blind, in relation to that of the sighted, is manifested mainly in
beginning of the development of psychic functions. In the previous three chapters
we have seen how from a certain moment the possibilities of
knowledge and the creation of meanings become functionally equivalent in
blind people and the sighted. Throughout the development, as experience increases
subject, the states of knowledge, the semiotic component of representation, is going
making it more important and this causes the differences between the blind and the sighted to fade away
diluting. Not surprising at all if we think that, then, both sides are
using the same mediation instruments in similar social activities. In
In that case, we
we would find that there are actions in which there would be no differences between the operations
what blind and sighted people do, in which both groups of subjects engage
similar functional systems. In that case, there should be no differences either in
the times nor in the levels of execution of one and the other.
Let's develop this same idea from another point of view. We said earlier that
the consequence of initiating a representation process is the creation
of meanings, which are social and are acquired through activity. The blind
they are people who, to the extent that they are socially integrated, find themselves imbued with
a single universe of meanings, although their subjective experience, the sense of their
sensory experience can be different. What we are doing is highlighting again
the enormous power of normalization or unification of mediation instruments
semiotics.
Obviously, this normalization depends on the level of social integration of the subject.
It is not uncommon for blind people (children and adults) to experience cases where, due to
various circumstances, they are very socially isolated. In such cases it can
to reach a significant lack of sensory stimulation in the environment, a
certain sensory isolation; if this is accompanied by a certain social isolation,
we can encounter cases where the effects of a deficit stimulate
sensory are added to those of another social and affective. It is not strange, then, that, when
If such circumstances arise, serious limitations appear in behavior and in the
use of knowledge access strategies, sometimes combined with the presence of
stereotypies, 'blindnesses' and, even, sometimes to disorders so severe that
lead to professionals who work with them considering them as cases of
autism associated with blindness.
But let's see next how these general issues that we have just
exposing is embodied in some of the specific areas we have examined in
the previous chapters of this volume.

3.3. Representation of the environment and mobility

Spatial representation is a paradigmatic example of everything we have just

speak about representation. In the chapter dedicated to the topic that gives title to this
epigraph, we emphasized the importance it has for blind people to generate and
use spatial schemas to compensate, in this way, for the scarcity of information about
the environment that they can gather with the sensory systems they have. Let's think.
that a blind person is not offered the enormous amount of simultaneous information that, with
a great efficiency and speed, the visual system presents about the arrangement and
circumstances of the environment in which the seeing subject moves.
Let's note that a seer who moves constantly updates their position by means of
direct visual perception. That subject has to make decisions about the route to follow, in
function of the estimation that it makes of its position and the level of knowledge it has
from that specific environment, but is always aware of the environment in which it moves,
well, it is presented through direct perceptual means, and for that reason, it has more ease to
represent the absent parts of that environment based on the sensory cues that it
vision presents itself in an apparently immediate way. A blind person, however, ...
find that the sensory information provided about the environment is much
more restricted, we could even say that the environment does not present itself in a massive way
and direct to perception, but it collects small ones slowly and sequentially.
units of information that must be integrated by the psychic apparatus of the subject
through the use of conscious strategies that can later become automated.
blind, consequently, does not perceive the environment in the same way as the sighted, does not
it is presented to him in such a massive way, but he has to represent it to himself. In other
words, situating oneself on a street, something that does not pose any effort to
a seer, for whom the solution to this task appears as something immediate and that
it does not require any effort, however, it constitutes an effort for the blind person
on quite important occasions, as it requires the implementation of strategies
aware, that they necessarily have to resort to prior knowledge and that they require
of a conscious processing far superior to that which occurs in the case of the seer,
with a greater possibility of error, which produces greater anxiety and which can lead to
become an unpleasant experience for those who have to navigate in it
environment in this way.
The essential difference between the blind and the sighted, regarding the handling of the
spatial information and mobility and wandering would then be that the
psychics mainly use contextual information that they gather in a very
efficient through vision; this visual information is processed very quickly and
efficient, also produced in an encapsulated and inaccessible functional system
direct form to consciousness. The blind person, on the contrary, gathers a amount of
much less information and must handle it using conscious mechanisms
representation whose acquisition is slower and more laborious. It is not about, at all
way, to suggest that the spatial knowledge that some and others have must be
not necessarily always better or worse in one case than in the other, but rather to achieve
the same level of performance in the same spatial task the level of training,
the conscious operation, the effort to be made by the blind person is always far greater.
What we just said allows us to explain the peculiar structure of returns.
observed in figurative-spatial tasks performed by blind subjects and
seers of various ages who use vision in some cases and in others see themselves.
forced to work tactilely. It is curious to observe how the performance of the
the blind is shown to be very inferior to that of sighted people who work visually, showing
a delay in the execution of space tasks compared to evolutionary type designs
transversal appears to be very important (for several years), but, however,
Then it disappears with great speed. The performance of the seers who work
tactilely it is even more surprising, because when the tasks they perform do not
Familial results show behavior very similar to that of the blind. Said in
other terms, it seems as if being forced to work tactilely they "returned" in
the development of their figurative-spatial knowledge forms (cf. Ochaíta, 1982;
Ochaíta and Rosa, 1988; Rosa, 1981; Rosa and Ochaíta, 1988). The explanation now seems
obvious: blind people can perform those tasks when they have strategies for
global representations, which is why there seems to be a qualitative leap in their
spatial ability at a given moment. On the other hand, psychics can
to carry out this task much earlier thanks to the use of vision dispenses them from the
the need to have a highly elaborate spatial representation, however,
when they change sensory modalities, the cognitive structure of the task changes, and,
In this case, the seers find themselves having to work on the same things.
conditions that the blind have, but also with the added factor of their lack of
training to work this way.
Ultimately, when wandering around the environment, we could say that one either resorts to
working with previously held representations of space is very difficult and,
it's even dangerous to move around, as the sensory data collected are
necessarily very fragmentary, and only make sense within a representation
more or less global and integrated and that has been previously constructed. Of course
Creating those spatial action guidelines is something laborious and costly when accessed in
knowledge of the environment in a partial and fragmented way, as happens in the absence
of sight, but it is something absolutely necessary for the blind person to achieve the necessary
personal autonomy. If we are allowed the metaphor, we would dare to compare the
walking without vision to high-altitude navigation in fog; just a few strategies
Conscious and with a high cost in attentional resources, they allow to maintain the course and
to reach the desired destination, and success will only be possible if there is a representation
the environment in which one is moving, and a technique that allows estimating the
position at each moment and update the course.
The example we just used is eloquent in highlighting a
issue that we believe is important. The conscious strategies of spatial representation
and orientation are susceptible to benefiting from cultural mediation instruments.
Let’s think, for example, about conventions such as orthogonality or points.
cardinals that allow creating a type of decontextualized discourse that enables
precise verbal descriptions of spatial issues. Thus we find that
the cartography and the vocabulary derived from it, or from geographic or geometric discourse,
they are highly relevant for developing spatial representation and strategies
of orientation and mobility.
The complexity of the processes involved in the tasks we have been addressing
referring to it highlights the suitability of formal instruction for
facilitate the achievement of effective spatial schemes. The blind person has
that learning to gather and analyze with the available resources the most important environmental keys
relevant to be able to move around. It must also be capable of organizing the
relationships established among the elements of the environment without having them present
globally, at least in the same way it happens when using vision. But the
the necessary labor to be able to orient oneself and move in an environment is not limited only to
collect and relate the data from the environment, it must also carry out a series of
cognitive operations such as inferences, analogies, transpositions, etc.,
processes and relationships known or used on previous occasions different from those of
moment and the specific situation of their current displacement. All of this makes it that
task that a blind person faces when making a movement
very different from what a clairvoyant has to do who makes the same journey. The
the amount and complexity of the computations, and the effort that this implies, will be very
different for one and the other.

3.4. The tactile reading of Braille

Once again we are faced with a task, in this case of a strictly

cultural, whose components are very different depending on the type of code of
notation used and the type of sensory access system with which it is collected
Information. The act of reading has a distinct operational structure if performed by a
blind, using Braille, and a sighted person reading in "ink", even if both have a level
of high reading competence, and they do it in the same native language shared by the
two.
Previously, in the chapter dedicated entirely to examining the characteristics
peculiarities of braille reading, we have highlighted that the origin of the peculiarities that
they occur in the tactile reading process of Braille are in the very characteristics of the
touch that imposes a set of restrictions on subsequent operations to be performed
within reading actions. First of all, it must be taken into account that the field
perceptive that this sensory modality allows for the first phase of the act of reading
braille (when reading with the tip of a finger) encompasses only one braille cell, which is what
same as a letter, while the seers can collect in each visual fixation
an amplitude
of more than one word. This brings consequences already from the early stages of the process
reader. The most plausible interpretation of the data is to consider that the subject
the reader must explore letter by letter and store in a temporary buffer of the memory of
I work with the information that is collected until this information allows access to the
lexicon. The existing experimental evidence (cf. Fernández et al., 1988; Millar, 1976;
Ochaíta et al., 1988; Pring, 1985; Rosa et al., 1986) points out how this information that
it can be stored in both a tactile and phonemic format.
The consequences of the way of collecting and storing information seem to be
determinants for the later phases of the reading process. Probably the process of
production of meaning (or access to the lexicon if that is preferred to be called) will not be
never equivalent in the blind and the sighted. While it is usually considered that a reader
a clairvoyant can activate the meaning of a word through a direct path (without
need
from a phonemic mediation) in the case of the blind, it does not seem that this can reach
is never possible. Perhaps the closest thing that can be found to it is a process
inferential in which after the exploration of the initial letters of a word, and with the
context help activates a probable meaning of the word within the context, this
may lead to word recognition errors and, therefore,
consequence, that affects the understanding of the text, something that effectively appears
empirically (cf. Ochaíta et al., 1986).
The process of tactile reading in Braille appears, then, to be quite different and
with phases that do not necessarily coincide with those that occur in the case of reading
visual alphabet., Moreover, it seems that the fragmentation and sequentiality that touch
It imposes, and the need for a temporary memory hold would force a greater
slowness of the global reading process, since there is a greater number of processes
which, as one might suppose, takes time. This interpretation seems to be consistent with
the reading speed data provided by existing empirical studies and that
we have presented in the chapter monographically dedicated to this topic. Moreover, this
data interpretation seems to suggest the existence of an absolute limit in the
braille reading speed.
Anyway, this explanation, although it seems the most coherent in light of the
the data we have does not leave us completely satisfied, as there is in the literature
data on reading speed that challenge this interpretation. But this should not
to discourage ourselves, for perhaps the tactile reading of Braille is one of those examples, for
another very frequent part, in which there is not a unique way to execute a task, but
that it is necessary to use different strategies to carry it out. If the case we are dealing with is
one of these will require further investigation, or an interpretation of the evidence
empirical different from the one we offer here, to be able to explain those results
discrepancies.
In any case, what does seem difficult to dispute is that this different way of reading
It must be learned differently from visual reading and its learning does not follow
neither the same route nor the same timing as that one. But that is nothing more than a
special case of the relationship between development and learning in this type of subjects.
Let's now focus, to finish up, on this aspect.

3.5. The development

From everything said so far, one could deduce that if development is the construction of
functional action systems, based on the previously existing natural systems,
The history of the development of each concrete subject must necessarily be a story.
different, since the actions that this person has taken would be different and would be in
function of the activities in which he/she has been involved. This implies that in the
In the case of the blind, important variations should appear in the rhythm and form of the
development regarding what happens in the case of normal subjects. Aspects that, in
in any case, they would also be strongly affected by the conditions of
channeling of development that occurs in each case.
Throughout this work, it has been argued that the heterogeneity in the
development, which becomes evident when comparing subjects with physical conditions or
different social ones must be explained by referring to 'homogeneous principles'
and generals for the entire species. Let us therefore try to outline some of the different
sources of diversity, using for this the explanatory mechanisms that we have
been exposing.
First of all, it should be noted that, in contrast to the heterogeneity that represents the
to have a distinct natural 'toolbox' different from that of the generality of the
population, there are some other factors that act as levelers and compensators
of that deficit. The integration and participation in the activities of the social group to which
it belongs is, in this sense, a first-order leveling element. The more
if an individual is integrated, the result of their development will be closer to that of the
the generality of the population. Conversely, the further away it is, the more
isolated from participation in cultural practices, more distinct, more "backward"
will appear before those who consider themselves constituents of the so-called normality. But this
it is not exclusive heritage of the blind, nor even of those with some kind of
deficiency, but it is also valid for all people with some type of marginalization
social or cultural, regardless of the factor that may have caused it.
But, in any case, one must not forget the specificity of each case and each type.
of the problem. In the particular case at hand, the development of the blind and
visual impairments, sensory restrictions impose a set of conditions
whose consequences are still present even in the most favorable situations, and that
we will try to outline next, based on both the theoretical instruments that
so far we have managed, as from the empirical data offered by the literature
psychological and that we have gathered in the chapter dedicated to the study of development.
We have repeatedly pointed out that having collection systems
particular information both restricts the type of information that is collected as
it imposes the execution of a set of perceptual operations very different from those that
they have to be carried out by other people who also have the vision. But the environment
physical and social, and the social practices carried out in it do not conform to the
peculiarities of the individual with deficiencies, but it is generally the individual who has to
to adapt to them. This forces one to undertake a set of learnings, to structure the
acquisition of their skills in a certain way. When it occurs the
intersection between those learning of action skills about the physical environment and
social with the help of cultural tools and physical maturation we talk about
development.
A development that, then, will have specific characteristics for circumstances
concrete. Let's examine what these are in the case of the blind.
We have insisted in the previous sections on the consequences of not having the
vision, of having to use the most fragmented and disintegrated information that they offer
the other sensory modalities. This, we have said, forces us to work with a greater
number of information units, but with a much lower informative value, it
what makes the processes of knowledge more cumbersome, difficult, slow, and more
susceptible to making mistakes. Knowledge functions that are often considered
as very natural, although the processes on which they rest are of a great
complexity - as is the case with orientation and wandering - take a
completely different dimension and require a much greater effort.
It seems undeniable that these sensory restrictions will produce a representation.
phenomenon of a world very different from that of the seer with some formats of
conscious representation qualitatively distinct, with a probably aesthetic
incomparable. Those representations, necessarily mediated by the interfaces
sensory experiences that the subject has will act as the first significants for the
access to the symbolic function.
It should not be surprising, then, that all those tasks in which the
visual representation modes turn out to be the most evolutionarily adapted for their
resolution, as is the case with the collection of remote spatial information, result in
more difficult for the blind, and require a longer learning process and
neat. And precisely because of the structure of the task that the blind have to
performing is very different from what the psychics do. This does not mean that it is about
of impossible tasks, but they must be mediated differently, using
different procedures and different cultural instruments to achieve the same
function. The case of Braille is paradigmatic in this regard.
If it turns out that the phenomenal representations of the blind are different from those of the
clairvoyants, if the operational structure of the tasks that must be carried out to execute the
the same social activities are not the same either, so it should not surprise us,
that the moments when those skills are achieved are also different and that the
Image of the development that appears when testing procedures are applied.
taken from the descriptive psychology of the development of normal Western subjects
and urban areas are equally different. The image that appears, then, is that of a
development in a somewhat anomalous way, with periods of enormous "delays" in some
moments and of surprising "recoveries" in others, when, if we applied another
a different conceptual scheme should not include either of them, but rather the
outline of a development, of a composition of functions that is expected to
Based on the resources available to the blind and the activities they must engage in
perform.
We have already pointed out before that there are differences in representation.
phenomenal, or what is equivalent, in the conscious format of representation -or, to
another level, in the type of analog scheme that is activated - does not imply that the
meanings may be different, because they are not something that is implicit in the objects
of the world, but rather they are a product of human action upon them. If the
the representation of the world, we said, is phenomenologically distinct, this does not imply
that the blind have a semantics and a universe of meanings different from that of the
seers. This is evidenced in some experimental results
apparently surprising and that we will examine next.
Works like those of Craig (1973), Hans (1974), or Jonides, Khan, and Rozin (1975), which
They start from the use of paired associate word recall tasks of high and low.
sensory imagery in different modalities - using word lists for that
made by Paivio, Yuille, and Madigali (1968) - do not find differences in
performance between the blind and the sighted, even in words with high imaginative content
visual, what is interpreted as a consequence of a semantic processing of the
information. These results coincide with those of Rosa and colleagues (1986)
obtained using a similar technique. On the other hand, these last authors
they found, using the incidental learning technique through tasks of
Craik and Tulving's (1975) orientation with words of high visual imagery and high imagery
auditory - that blind adolescents reached the same level of performance as the
psychics in the memory of words with high visual content, at the same time that
they showed an acceptable domain in formal thinking tasks at the same level of
performance that seers (cf. Pozo et al., 1985). That is to say, it seems that the differences
between the blind and the sighted become irrelevant when both groups have to perform
tasks susceptible to being resolved through semiotic mediation. It is even possible
that many tasks that for a seer it is more economical to solve using
forms of analog representation, must be approached by the blind through
other forms of mediation.
We find ourselves, then, that despite starting from a structural heterogeneity
Initially, it is possible to achieve significant levels of functional homogeneity. But
for this it is important that the appropriate conditions for channeling are provided
development to which we have referred above.
In the introductory chapter of this volume, we have criticized what we called
"normocentrism," that is, the consideration that the way of performing tasks, or
the development pattern, of the part considered as normative of the population is the
criterion of normality and desirability. This stance implies that to conform
Adequately to the environment, there is only one system, or at least one better or more desirable.
We find ourselves, then, with what is a description of some
behaviors of a group become a guiding norm for others
groups from that same population (or even from others). We are not going to attempt to enter here
in a discussion about the concept of normality, we just want to point out that
if one of the goals of education for individuals with disabilities is to try to
eliminate, or at least minimize their disability, make them as socially valid as possible
in terms of employment, it does not "imply that neither the procedures, nor the steps, nor the route, nor the
timing must be identical to that of the rest of the population. Precisely the
study of the peculiarities of these subjects, and the techniques and instruments to be used
with them, they provide an invaluable contribution to the study of the human phenomenon,
enriching our knowledge about it.
As Valsiner (1987) points out, the development models that are usually worked with...
developmental psychology is built from data collected from work with
middle-class children from advanced Western societies. Development theories
that derive from it tend to universalize particular characteristics of this type of
population. If Valsiner proposes to study subjects from other societies and other groups
social, we believe that the case of individuals with physical deficiencies in general, and of the
blind people in particular, provides data that may be of interest in that attempt to improve the
knowledge of the processes in development.

4. As an epilogue: integration

This last section is not going to be very extensive, as what has been presented so far
Here is the bulk of the message we intend to convey. Our intention here is
limits itself to pointing out some aspects and trying to offer some recommendations
concrete.
First of all, we would like to point out some of the shortcomings that we have observed in
the literature dedicated to the psychology of blindness. We believe it would be important
methodologically complement experimental research with work on
empirical observation and case studies, especially on aspects such as the
interaction and communication, the development of symbolism and language, evolution
of emotions and motivation and, of course, the construction of personality. And
Hello, both in natural conditions (the family, school, or work environment), as well as in
the controlled conditions of the laboratory.
If the experimental psychology that works with groups allows exploring mechanisms of
In general, case studies allow to illuminate the presence of situations and
conditions that are rejected at the ends of the tails of the distributions
statistics and yet require such a general and universal explanation
like that of psychological laws that result from phenomena that emerge in more areas
close to the median of the distributions.
Finally, we want to revisit some Vygotskian ideas that, despite the time
Time elapsed since they were minted still results in a strength and freshness.
surprising. In one of his works written in 1924, but published for the first time in
1972, points out a question that, although it initially seems evident, we believe results
fundamental to always keep in mind: the education of the deficient subject should not be
an education to live with deficiency must be an education to correct
functionally that deficiency, to integrate actively into society, not to live
in a refuge, no matter how privileged it may be. One does not have to work to
for an individual to know how to be deaf, blind, or a cerebral paralytic, but rather so that they can be a
efficient citizen. In this sense, Vygotsky rejects any notion of pity or of
philanthropy, which only serves to pathologize the subject, and points out the need for
considering a demanding education. And this must be done, on one hand, by changing the
social consideration of deficiency and, on the other hand, stretching to the maximum all the
possibilities for the child to achieve the compensation we were talking about
beginning of this book. In this sense, the education of the deficient should not give up
from the outset to achieve the same objectives as those of the so-called normals, although
always within reasonable limits (e.g. athletic brands cannot be asked for)
in physical education a cerebral palsy patient, or, that the blind sew borders within the
training process for pre-writing). Thus, we would be in favor of the application of
the criteria standards in the evaluation of their academic progress, which should not be
tangled with the necessary adaptation of the materials for proper handling of the
environment, nor to the implementation of individualized curricular adaptations that
adapt the school curriculum to the developmental sequence observed in these children.
Regarding this last point, it is necessary to carry out a careful evaluation of the
development of the blind, and here we must forget about standardized norms,
since what matters is not comparing a specific subject with others, but
establish what your skills are so that, based on them, you can provide the instruments
and the activity systems that allow it to progress in its development. In this sense there are
that combines maximum respect for heterogeneity, but within an inflexible
tendency towards functional normalization.
Although there are operational differences, what matters is the possibility of carrying out the
precise actions in the physical and social environment. Precisely the integration, through the
normalization process that involves, allows the acquisition of the precise skills
for the execution of social activities. The fact that at certain moments
development, a person with deficiencies has to resort to mediation tools
adapted to their physical conditions - which makes them use
operational resources different from those of subjects without deficiencies - finally it is not
more than an anecdote, once the learnings on which have already taken place
rest the development and the subject is already integrated into social practices. But, until
that this is the case, the recognition of its peculiarities is essential in order to be able to
provide them with the instruments and the ideal learning conditions that they
allow for development in harmony with the demands of the society in which
they live.
Finally, we cannot help but insist that the worst effect of deficiency is not
it is the defect that causes the physical relationship with the world, but the alteration that occurs
produce in the relationship with others. This is often the result of the idea that
the others have deficiency, often as a consequence of visions
excessively physicalists. This is vividly expressed by Vygotsky in the quote with which
we conclude.
In summary, the issue from both the pedagogical and psychological aspects has been
generally posed from a strictly physical, medical point of view. The defect
The physical has been studied and compensated as such: blindness has simply meant the
lack of vision, deafness, and hearing impairment, as if it were a blind dog or a
deaf jackal. In this case, it has been overlooked that, unlike the animal, the defect
the organic aspect of a person can never directly influence their personality because the
the eye and the ear of man are not only his physical organs, but also the organs
social, because between the world and man, there is also the social medium that
reflects and directs everything that comes from man to the world and from the world to him
man. In man, there is no direct, asocial, and pure relationship with the world. The
lack of vision or hearing means therefore, above all,
the disappearance of very important social functions, the transformation of the
social relations and the destruction of all systems of behavior. The problem of the
Deficiency in psychology and pedagogy needs to be addressed and understood.
as a social problem, because its social moment, which had not been noticed before,
what has generally been considered secondary actually turns out to be the primary and
principal". (1983, p. 62-63).
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Published titles

Psychology Minor Alliance

1 Acts of Meaning Jerome Bruner

2 Objects with Mind Angel Riviere
3 Autism Vta Frith
4 Knowledge as Desire Hans G. Furth
5 To be born knowing Lacques Mehler Ernrnanuel Dupoux
6 Conceptions of Childhood
Ben S. Bradley
The articulated mammal
lean Aitchinson
8 Children and emotions
Paul L. Harris

Psychology Alliance

1 Readings in psychology of thought

Compilation by Mario Carretero and Juan A. García Madruga
Action, thought, and language.
Jerome Bruner Compilation by José Luis Linaza.
3 Introduction to cognitive psychology
Manuel de Vega
4 Language and speech
George A. Miller
5 Learning and memory
Donald A. Norman
The language of thought
Jerry A. Fodor.
7 The future of cognitive psychology
Richard E. Mayer
8 Psychology of Reading
Robert G. Crowder
9 Developmental Psychology 1
Compilation by A. Marchesi,
M. Carretero and J. Palacios
10 Developmental Psychology 2
Compilation by J. Palacios,
A. Marchesi and M. Carretero
11 Developmental Psychology 3
Compilation of M. Carretero,
J. Palacios and A. Marchesi
12 The vision
David Marr
13 autistic children
Niko Tinbergen and Elisabeth
A. Tinbergen
14 Brothers and sisters
Judy Dunn and Carol Kendrick
15 Introduction to Environmental Psychology
Compilation of Florencio Jiménez Burillo
and Juan Ignacio Aragonés
From the eye to the vision
John P. Frisby
17 The cognitive and linguistic development of deaf children
Alvaro Marchesi
18 The subject of cognitive psychology
Angel Riviere
19 Live and learn
Guy Claxton
20 Discourse Analysis
Michael Stubbs
21 Schizophrenia: a cognitive approach
José María Ruiz-Vargas
22 Left brain, right brain
Sally P. Springer and Georg Deutsch
23 The discovery of meaning
Katherine Nelson
24 History of Animal Psychology
Robert A. Boakes
The social world in the child's mind
Compilation by Elliot Turiel, Ileana Enesco, and Josetxu Linaza
26 Comparative Cognition Compilation by Luis Aguado Aguilar
27 Multivariable experimental designs
Jaume Arnau i Gras
28 Psychology of Perception
29 Reading and comprehension Manuel de Vega, Manuel Carreiras, Manuel Gutiérrez-Calvo,
M.. L. Alonso-Quecuty
30 Psychological development and education, 1
Compilation of J. Palacios,
A. Marchesi and C. Coll
31 Psychological Development and Education, 2 Compilation by C. Coll, J. Palacios
y A. Marchesi
32 Psychological development and education, 3 Compilation by A. Marchesi, C. Coll and J.
Palaces
33 Readings in Psycholinguistics, 1
F. Valle edition,
F. Cuetos, J. M. Igoa
and S. del Viso
34 Readings of psycholinguistics, 2
Edition of F. Valle,
F. Cuetos, J. M. Igoa
y S. del Viso
35 Psychology of Memory
José María Ruiz-Vargas
36 Biology of behavior and the mind
Bruce Bridgeman
37 Introduction to the parallel distributed processing David E. Rumelhart,
James L. McClelland
and the PDP group
38 Dyslexia
Michael E. Thomson
Psychology of blindness
Compilation by Alberto Rosa and Esperanza Ochaíta
40 Biology of human behavior
Irenaus Eibl-Eibesfeldt