Human brain is consisting of two hemispheres separated by a deep vertical fissure

(deep furrow or groove.) and connected to each other by broad band of nerve fibres called

corpus callosum. Both the cerebral hemispheres are not functionally equivalent. Some

functional asymmetries are well known. Cerebral dominance refers to the dominance of one

cerebral hemisphere over the other in the control of cerebral function (Sembulingam,2012).

The term lateralization refers to the tendency for a given psychological function to be

served by one hemisphere, with the other hemisphere either incapable or less capable of

performing the function. The nervous system in human is predominantly contralateral, which

means that one half of the brain controls the other half of the body. This contralateral

structure allows investigators to test more precisely the functions of the two hemispheres in

the split-brain patient by presenting stimuli to just one side of the brain and observing the

resulting behavior. The goal of these studies is to determine what skills are lateralized to one

or the other side of the brain.

In 1861, Paul Broca reported his postmortem examination of two aphasic patients.

Aphasia is a brain damage–produced deficit in the ability to produce or comprehend

language. Both of Broca’s patients had a left-hemisphere lesion that involved an area in the

frontal cortex just in front of the face area of the primary motor cortex. By 1864, Broca had

performed post-mortem examinations on seven more aphasic patients, like the first two, they

all had damage to the inferior prefrontal cortex of the left hemisphere—which by then had

become known as Broca’s area.

In the early 1900s, another example of cerebral lateralization of function was

discovered. Hugo-Karl Liepmann found that apraxia, like aphasia, is almost always

associated with left-hemisphere damage, despite the fact that its symptoms are bilateral

(involving both sides of the body). Apraxic patients have difficulty performing movements

when asked to perform them out of context, even though they often have no difficulty

performing the same movements when they are not thinking about doing so. The combined

impact of the evidence that the left hemisphere plays a special role in both language and

voluntary movement led to the theory of cerebral dominance. According to this theory, one

hemisphere—usually the left—assumes the dominant role in the control of all complex

behavioural and cognitive processes, and the other plays only a minor role. This thinking led

to the practice of referring to the left hemisphere as the dominant hemisphere and the right

hemisphere as the minor hemisphere (Pinel & Burnes, 2018).

Normal individuals use the skills of both hemispheres to comprehend and produce
Language. Kaplan, Brownell, Jacobs, and Gardner (1990) examined the ability of individuals

with right-hemisphere brain damage to interpret conversational remarks. Bever (1980) has

argued that the left hemisphere prefers to process information in a relational manner, whereas

the right hemisphere uses a holistic mode of processing. Holistic processing involves the

activation of a single mental representation of a stimulus. Relational processing involves the

activation of at least two distinct representations along with some relation between the two.

The two cerebral hemispheres cooperate with each other. They do not perform

identical functions. Some of their functions are lateralized, that is, they are located primarily

on one side of the brain. The left hemisphere participates in the analysis of information, the

extraction of the elements that make up the 150 wholes of an experience. The left hemisphere

is good at recognizing social information, particularly social events that occur one after the

other. The left hemisphere is also involved in controlling serial behaviours. Although in some

individuals, the functions of the left and right hemispheres are reversed. The functions of the

left hemisphere include verbal activities, such as talking, understanding the speech of other

people, reading, and writing. Any damage to this hemisphere interferes in these abilities

(Khosla,1965).

Superiority of the left hemisphere in controlling ipsilateral movement

One unexpected left-hemisphere specialization was revealed by functional brain-

imaging studies. When complex, cognitively driven movements are made by one hand, most

of the activation is observed in the contralateral hemisphere, as expected. However, some

activation is also observed in the ipsilateral hemisphere, and these ipsilateral effects are

substantially greater in the left hemisphere than in the right. Consistent with this observation

is the finding that left-hemisphere lesions are more likely than right-hemisphere lesions to

produce ipsilateral motor problems—for example, lefthemisphere lesions are more likely to
reduce the accuracy of left-hand movements than right-hemisphere lesions are to reduce the

accuracy of right-hand movements (Pinel & Burnes, 2018).

Superiority of the right hemisphere in spatial ability

In a classic early study, Levy (1969) placed a three-dimensional block of a particular

shape in either the right hand or the left hand of split-brain patients. Then, after they had

thoroughly palpated (tactually investigated) it, she asked them to point to the two-

dimensional test stimulus that best represented what the three- dimensional block would look

like if it were made of cardboard and unfolded. She found a right- hemisphere superiority on

this task, and she found that the two hemispheres seemed to go about the task in different

ways. The performance of the left hand and right hemisphere was rapid and silent, whereas

the performance of the right hand and left hemisphere was hesitant and often accompanied by

a running verbal commentary that was difficult for the patients to inhibit. Levy concluded

that the right hemisphere is superior to the left at spatial tasks. This conclusion has been

frequently confirmed and it is consistent with the finding that disorders of spatial perception

tend to be associated with right-hemisphere damage (Pinel & Burnes, 2018).

Specialization of right hemisphere for emotion

According to the old concept of left-hemisphere dominance, the minor right

hemisphere is not involved in emotion. This presumption has been proven false. Indeed,

analysis of the effects of unilateral brain lesions indicates that the right hemisphere may be

superior to the left at performing some tests of emotion—for example, in accurately

identifying facial expressions of emotion. Although the study of unilateral brain lesions

suggests a general right-hemisphere dominance for some aspects of emotional processing,

functional brainimaging studies have not provided unambiguous support for this view (Pinel

& Burnes, 2018).

Superior musical ability of the right hemisphere

Kimura (1964) compared the performance of 20 right-handers on the standard digit

version of the dichotic listening test with their performance on a version of the test involving

the dichotic presentation of melodies. In the melody version of the test, Kimura

simultaneously played two different melodies—one to each ear—and then asked the

participants to identify the two they had just heard from four that were subsequently played to

them through both ears. The right ear (i.e., the left hemisphere) was superior in the perception

of digits, whereas the left ear (i.e., the right hemisphere) was superior in the perception of

melodies. This is consistent with the observation that right temporal lobe lesions are more

likely to disrupt music discriminations than are left temporal lobe lesions.

Hemispheric differences in memory

Early studies of the lateralization of cognitive function were premised on the

assumption that particular cognitive abilities reside in one or the other of the two

hemispheres. However, the results of research have led to an alternative way of thinking: The

two hemispheres have similar abilities that tend to be expressed in different ways. The study

of the lateralization of memory was one of the first areas of research on cerebral lateralization

to lead to this modification in thinking. Both the left and right hemispheres have the ability to

perform on tests of memory, but the left hemisphere is better on some tests, whereas the right

hemisphere is better on others. There are two approaches to studying the cerebral

lateralization of memory. One approach is to try to link particular memory processes with

particular hemispheres—for example, it has been argued that the left hemisphere is

specialized for encoding episodic memory. The other approach is to link the memory

processes of each hemisphere to specific materials rather than to specific processes. In

general, the left hemisphere has been found to play the greater role in memory for verbal

material, whereas the right hemisphere has been found to play the greater role in memory for

nonverbal material. Whichever of these two approaches ultimately proves more fruitful, they

represent an advance over the tendency to think that memory is totally lateralized to one

hemisphere.

Theories of cerebral dominance

The dominance failure theory proposes that specific learning difficulties are due to

failure of one side of the brain to become dominant over the other. This is a theory that is

often too readily accepted by those who use terms such as ‘cerebral dominance’ and

‘laterality’ without realizing how difficult these are to ascertain, and how complex their

interrelationship is. This theory states that one cerebral hemisphere has to dominate over the

other, that 153 is, become specialized in certain functions, notably language, in order for a
child to be able to learn. If this does not occur, it will give rise to confusion and delay. This

theory, therefore, remains unproved.

The analytic–synthetic theory

The analytic-synthetic theory of cerebral asymmetry holds that there are two basic

modes of thinking—an analytic mode and a synthetic mode—which have become segregated

during the course of evolution in the left and right hemispheres, respectively. According to

this theory, the left hemisphere operates in a logical, analytical, computerlike fashion,

analyzing and abstracting stimulus input sequentially and attaching verbal labels; the right

hemisphere is primarily a synthesizer, which organizes and processes information in terms of

gestalts, or wholes (Harris, 1978). Although the analytic–synthetic theory has been the

darling of pop psychology, its vagueness is a problem. Because it is not possible to specify

the degree to which any task requires either analytic or synthetic processing, it has been

difficult to subject the theory to empirical tests (Pinel & Burnes, 2018).

The motor theory

The motor theory of cerebral asymmetry (Kimura, 1979) holds that the left

hemisphere is specialized not for the control of speech specifically but for the control of fine

movements, of which speech is only one category. Support for this theory comes from reports

that lesions that produce aphasia often produce other motor deficits. One shortcoming of the

motor theory of cerebral asymmetry is that it does not suggest why motor function became

lateralized in the first place (Pinel & Burnes, 2018).

Linguistic theory.

A third theory of cerebral asymmetry, the linguistic theory of cerebral asymmetry,

posits that the primary role of the left hemisphere is language; this is in contrast to the

analytic–synthetic and motor theories, which view language as a secondary specialization

residing in the left hemisphere because of that hemisphere’s primary specialization for

analytic thought and skilled motor activity, respectively. The linguistic theory of cerebral

asymmetry is based to a large degree on the study of deaf people who use American Sign

Language (a sign language with a structure similar to spoken language) and who suffer

unilateral brain damage. The fact that left-hemisphere damage can disrupt the use of sign

language but not pantomime gestures (gestures that express meaning) suggests that the

fundamental specialization of the left hemisphere may be language.

The concept of specific right brain/left brain activities is an oversimplified, somewhat

"pop" notion. The brain is not some kind of computer with two main components called the

right side and the left side. It is, rather, an organic entity with sides, a top and a bottom, and

all the areas work together. There is, however, some evidence of preferential abilities that

may be associated with one side of the brain or the other. For example, the left hemisphere

appears to be better adapted to dealing with matters of language and reading, while the right

hemisphere seems to be more strongly linked with art and imagination. But the effects of a

slight dominance of one hemisphere over the other emerge as variations in style of

expression, rather than as differences in ability or intelligence.

Development Of Cerebral Dominance Scale

There are four major phases in the development of this inventory, they are, a) variable

selection b) Item formulation c) Item analysis d) Item selection Variable Selection For the

test construction, the initial step is variable selection. Hence, all the members started

discussion for finding variable according to the relevance of the subject. Finally, the

discussion has ended-up in the topic of “cerebral dominance” which was a still an interesting

area of psychology. Item Formation The next step in the construction of a test was the

formation of items for the test.

 Different aspects have to be kept in mind while preparing items for the questionnaire

which are:

• Use simple, clear and comprehensive language in statements.

• Avoid the statements giving more than one meaning.

• Statements should be precise, which do not exceed 20 words.

• Express only one idea in one statement.

• Avoid the words which could not be understood by the examinee.

• Avoid double negative statements.

• Each statement should contain only one complete thought.

A large number of items were written in accordance with the principles. The items

were constructed in both English and Malayalam. Then the items were discussed with

supervising teacher and modified the items as per their suggestions. After the modification,

the questionnaire consisted of 56 items and it was a 4-point scale. Both positive and negative

items were included.

Table 1: Break up of participants for item analysis

S.I.No Participants No of participants

1 Male 150

2 Female 150
Item Analysis

The third step in the construction of cerebral dominance scale was item analysis.

Sample

The sample consisted of 300 participants both male and female in the age 18 to 60

years. Among total participants ,150 were males and 150 were females. The sampling method

is snowball sampling.

Procedure And Administration

The data were collected from 18 to 60 years old participants from Kerala and they

were randomly selected and good rapport was established. The purpose of the study was

explained and the questions were distributed. There was given a set of instructions regarding

what to be done and how is to be done. Assurance of confidentiality was also given to the

participants and they were asked to choose the correct answers. The item questionnaire was

printed in both English and Malayalam. The responses were marked in terms of 4-point scale

urges Strongly agree, agree, disagree and strongly disagree. Demographic details of the

participants were also collected. The test was mean to be self-administered. However, the

investigator had to assist those who had difficulties in understanding the items and the mode

of responding to items. The filled questionnaires were collected and checked whether any

items were left and incomplete.

Scoring

The response was scored according to the norms and guidelines of the scale. The

score for the positive items were 4,3,2,1 corresponding to the response strongly agree, agree,

disagree and strongly disagree. And the negative items were scored 1,2,3,4 corresponding to
the responses as vice versa. The maximum score of the scale is 168. The scores were

analysed from the group. The item analysis of the scale was done using the Likert method

and ‘t’ value related to the item are given in table 2.

Group Mean S.D t- value

Item 1 1.91 0.581 5.331

Item 2 1.95 0.661 4.002

Item 3 1.81 0.710 4.445

Item 4 1.77 0.740 4.997

Item 5 2.13 0.881 3.849

Item 6 2.33 0.856 5.159

Item 7 2.39 1.002 6.605

Item 8 2.41 0.906 5.365

Item 9 1.77 0.694 3.467

Item 10 2.30 0.735 2.238

Item 11 2.71 0.781 1.528

Item 12 3.10 0.727 1.520

Item 13 1.81 0.708 6.569

Item 14 3.09 0.691 1.932

Item 15 2.36 0.721 6.642

Item 16 2.17 0.713 4.323

Item 17 1.91 0.665 8.479

Item 18 2.81 0.796 2.608

Item 19 1.93 0.844 5.595

Item 20 1.87 0.711 4.183

Item 21 2.80 0.801 1.098

Item 22 2.31 0.807 6.673

Item 23 2.55 0.890 5.382

Item 24 2.28 0.715 5.354

Item 25 2.54 0.993 1.230

Item 26 2.87 0.840 1.264

Item 27 2.30 0.885 1.433

Item 28 2.30 0.852 4.789

Item 29 2.98 0.630 0.224

Item 30 2.18 0.744 5.284

Item 31 2.40 0.760 3.294

Item 32 2.55 0.874 1.944

Item 33 2.29 0.823 5.378

Item 34 2.17 0.644 6.068

Item 35 2.55 0.818 1.294

Item 36 2.13 0.652 6.072

Item 37 2.25 0.761 0.192

Item 38 2.48 0.825 7.698

Item 39 2.43 0.893 6.390

Item 40 2.19 0.787 5.904

Item 41 2.80 0.821 3.308

Item 42 2.90 0.740 1.025

Item 43 3.11 0.796 0.222

Item 44 2.57 0.873 0.481

Item 45 2.48 0.738 0.265

 Item 46 1.96 0.763 4.572

Item 47 1.80 0.633 4.702

Item 48 2.43 01.034 0.979

Item 49 2.54 1.098 3.754

Item 50 2.36 0.842 4.702

Item 51 2.21 0.807 3.511

Item 52 2.04 0.697 4.635

Item 53 3.17 0.690 0.791

Item 54 2.12 0.755 4.384

Item 55 2.40 0.934 5.512

Item 56 1.94 0.666 4.659

Item selection

On the basis of item analysis 56 items of this questionnaire were selected. The

selected significant items are for the final version of the testing of this questionnaire, there

were some positive and some negative items.

Reliability

Reliability is the extent to which a test is internally consistent and has a predictive

purpose. For the present study, the reliability of the test has been established by the method of

Cronbach’s alpha and the alpha coefficients obtained is 0.781 & 0.612.

Reliability Statistics

Cronbach’s alpha No of items

0.781 38
 Reliability Statistics

Cronbach’s alpha No of items

0.612 16

Validity

Validity refers to the degree to which a test measures what it claims to measure. The

resulting validity found for the present test constructed is content validity. The research

experts’ opinions about the validity of the items were collected. According to their view point

the validity for the present test consists of content validity.

Significance

Cerebral dominance refers to the dominance of one cerebral hemisphere over the

other in the control of cerebral functions. It is the ability of one cerebral hemisphere to

predominantly control specific tasks. Accordingly, damage to a specific hemisphere can

result in an impairment of certain identifiable functions. Many studies and researchers are

going on with this concept. Through this study we are understanding the dominant brain of a

person and the abilities based on that. By knowing this, it is helpful for the person to choose

their job, career and future. Teachers can use this test to analyse their students’ abilities and

can treat them accordingly. Therefore, the significance of this concept is very important

nowadays. Thus, that is the reason of choosing this specific topic to study the dominance of

the cerebral hemispheres in human beings.

 Scope

At present the study has been conducted among 18 to 60 years old people. For future

research, it can be conducted to the special population like criminals, polices, college students

etc. And also, future research could be examined in a large number of participants.

References

Harris, L. J (1978). Sex differences in spatial, ability: Possible environmental, genetic, and

neurological factors. In M. Kinsbourne (Ed.

Personal Data Schedule

Name :

Age :

Sex :

Education :

Marital Status :

Religion :

Occupation
 NOBLE WOMEN’S COLLEGE DEPARTMENT OF PSYCHOLOGY

CEREBRAL DOMINANCE SCALE (2022)

Instructions

Some statements related are given below. There are four responses for each

statement (Strongly agree, Agree, Disagree, strongly disagree). Read each statement

carefully and select your response by putting a (✓) mark in the appropriate column.

Kindly give your response to all the items. Your response will be kept confidential

and will be used for research purpose only

S I No Statements Strongly Agree Disagree Strongly

agree disagree

1 I am good at analysing all

the different parts of a

problem.

2 I am proud of the creativity

of my work than the

thoroughness of my work.

3 Deadlines and schedules

make my work easier to do.

4 I prefer to finish one job

before starting a new one.

5 When I take " break" I relax

and do nothing.
6 I learn better from textbooks

than lectures

7 I would prefer a class in

mathematics than a class in

poetry.

8 I like working with numbers

than words

9 I believe there is an either

right or wrong way to do

everything.

10 I frequently change my

plans and find that sticking

to a schedule is boring.

11 I think it’s easier to draw a

map than tell someone how

to get somewhere.

12 I am able to thoroughly

explain my opinion in words

13 I would read the instructions

before assembling

something.

14 I need to set goals for

myself to keep me on a

track

15 I would like to respond to

 the word meaning rather

than persons word pitch and

feelings

16 I complete one homework

project at a time.

17 I generally use time to

organize work and personal

activities

18 I would like to sit left side

in a theatre.

19 I prefer multiple choice

questions than essay tests.

20 I prefer to solve problems

with logic.

21 I like to learn a movement

in sports or a dance step

better by hearing a verbal

explanation and repeating

the action or step mentally

22 I prefer the jobs in which I

work on many things at

once.2 3 . 2 4 .. 2 5 2 6 . 2

7 . I often forget to put

things back in their proper

place. 2 8 . I am a punctual
 person, rarely show up late.

29 . I often listen to my

intuition.

23 It is easy to remember some

history dates and facts for

me.

24 I would rather improvise

than carefully prepare a

speech to congratulate the

newlyweds

25 I rarely cry during sad

movies.

26 Sometimes I purchase

things I did not plan to buy

27

28

29