ASSIGNMENT II TRIMESTER III
COGNITIVE PSYCHOLOGY
Q 1.
Selective attention is the process of directing our awareness to relevant stimuli while ignoring
irrelevant stimuli in the environment. This is an important process as there is a limit to how
much information can be processed at a given time, and selective attention allows us to tune
out insignificant details and focus on what is important. This limited capacity for paying
attention has been conceptualized as a bottleneck, which restricts the flow of information.
The narrower the bottleneck, the lower the rate of flow. Concentration on certain stimuli in
the environment and not on others, enabling important stimuli to be distinguished from
peripheral or incidental ones. Selective attention is typically measured by instructing
participants to attend to some sources of information but to ignore others at the same time and
then determining their effectiveness in doing this.
Broadbent's Filter Model
Broadbent (1958) proposed that physical characteristics of messages are used to select one
message for further processing and that all others are lost. Information from all of the stimuli
presented at any given time enters an unlimited capacity sensory buffer. One of the inputs is
then selected on the basis of its physical characteristics for further processing by being
allowed to pass through a filter.
Because we have only a limited capacity to process information, this filter is designed to
prevent the information-processing system from becoming overloaded. The inputs not
initially selected by the filter remain briefly in the sensory buffer store, and if they are not
processed they decay rapidly. Broadbent assumed that the filter rejected the unattended
message at an early stage of processing. According to Broadbent the meaning of any of the
messages is not taken into account at all by the filter. All semantic processing is carried out
after the filter has selected the message to pay attention to. So whichever message(s)
restricted by the bottleneck (i.e. not selective) is not understood. Broadbent wanted to see
how people were able to focus their attention (selectively attend), and to do this he
deliberately overloaded them with stimuli. One of the ways Broadbent achieved this was by
simultaneously sending one message to a person's right ear and a different message to their
left ear. This is called a split span experiment (also known as the dichotic listening task).
Broadbent's dichotic listening experiments have been criticized because:
The early studies all used people who were unfamiliar with shadowing and so found it very
difficult and demanding. Eysenck and Keane (1990) claim that the inability of naive
participants to shadow successfully is due to their unfamiliarity with the shadowing task
rather than an inability of the attentional system.
Participants reported after the entire message had been played - it is possible that the
unattended message is analyzed thoroughly but participants forget. Broadbent's theory
predicts that hearing your name when you are not paying attention should be impossible
because unattended messages are filtered out before you process the meaning - thus the
model cannot account for the 'Cocktail Party Phenomenon'. Other researchers have
demonstrated the 'cocktail party effect' under experimental conditions and have discovered
occasions when information heard in the unattended ear 'broke through' to interfere with
information participants are paying attention to in the other ear. This implies some analysis of
the meaning of stimuli must have occurred prior to the selection of channels. In Broadbent's
model, the filter is based solely on sensory analysis of the physical characteristics of the
stimuli.
Experience: I have personally experienced this form of selective attention when I listen to a
podcast which requires careful concentration while I do chores around the house, including
doing dishes which can be loud; or when I can hear my friends call my name in a noisy
classroom.
Treisman's Attenuation Model
Attenuation theory is a model of selective attention proposed by Anne Treisman, and can be
seen as a revision of Donald Broadbent's filter model. Treisman proposed attenuation theory
as a means to explain how unattended stimuli sometimes came to be processed in a more
rigorous manner than what Broadbent's filter model could account for. As a result,
attenuation theory added layers of sophistication to Broadbent's original idea of how selective
attention might operate: claiming that instead of a filter which barred unattended inputs from
ever entering awareness, it was a process of attenuation. Thus, the attenuation of unattended
stimuli would make it difficult, but not impossible to extract meaningful content from
irrelevant inputs, so long as stimuli still possessed sufficient "strength" after attenuation to
make it through a hierarchical analysis process.
The difference between the two models is that Treisman's filter attenuates rather than
eliminates the unattended material. Attenuation is like turning down the volume so that if you
have 4 sources of sound in one room (TV, radio, people talking, baby crying) you can turn
down or attenuate 3 in order to attend to the fourth. This means that people can still process
the meaning of the attended message(s). In her experiments, Treisman demonstrated that
participants were still able to identify the contents of an unattended message, indicating that
they were able to process the meaning of both the attended and unattended messages.
Treisman carried out dichotic listening tasks using the speech shadowing method. Typically,
in this method participants are asked to simultaneously repeat aloud speech played into one
ear (called the attended ear) whilst another message is spoken to the other ear. For example,
participants asked to shadow "I saw the girl furniture over" and ignore "me that bird green
jumping fee", reported hearing "I saw the girl jumping over" Clearly, then, the unattended
message was being processed for meaning and Broadbent's Filter Model, where the filter
extracted on the basis of physical characteristics only, could not explain these findings. The
evidence suggests that Broadbent's Filter Model is not adequate, it does not allow for
meaning being taken into account.
Evaluation of Treisman's Model includes that Treisman's Model overcomes some of the
problems associated with Broadbent's Filter Model, e.g. the Attenuation Model can account
for the 'Cocktail Party Syndrome'. Treisman's model does not explain how exactly semantic
analysis works. The nature of the attenuation process has never been precisely specified. A
problem with all dichotic listening experiments is that you can never be sure that the
participants have not actually switched attention to the so called unattended channel.
Example: I have experienced this form of selective attention when I am in a group of people
wherein multiple people are talking. If I am listening to one person and another says
something, I will ask, “what?” but a few seconds later, I will be able to recall what the other
person said, thus proving that the other information was also attended to.
Q 2.
DICHOTIC LISTENING
Nature and capacities of Selective Attention
For this task, a video was played wherein each earbud played a different sound. Link-
https://www.youtube.com/watch?v=jAXV6APZVQI&t=59s
A dichotic-listening task requires the subject to shadow, or repeat aloud, a message presented
to one ear while ignoring a message presented to the other ear. Early work using the dichotic
listening paradigm revealed that subjects were very capable of successful shadowing and
successful blocking. In fact, subjects are so successful at blocking the unattended message
that little or no semantic content is ever reported from the irrelevant channel.
Mentioned below is a list of words that were played in each ear,
Left Ear : Right Ear :
Pat Bat
Bike Hike
Cow Pow
Take Make
Lake Bake
Row Hoe
Dark Bark
Cut Hut
Book Look
He Bee
Fun Bun
Rain Pain
Top Mop
Sew Bow
Kit Mitt
Met Pet
Man Can
Lawn Gone
Race Pace
Boot Toot
Pink Sink
I attempted to focus on the input in my right ear and wrote down what I heard. Some of my
observations are that due to the words being phonetically similar, it got a little hard to focus
on a specific word and often, the outcome was a word that sounded like an amalgamation of
both the words. Further, when I tilted my head or looked to my right, it seemed to help,
although this may just be based on my comfort and not an actual effect. For the results, I
could write down 4 of the words correctly while 3 others were phonetically close.
In another test, https://www.youtube.com/watch?v=zGKADgFCoeU&t=83s
There was a noisy conversation in my left ear and random phrases being spoken in the right.
This test was relatively simpler as there was no phonetic similarity and there were very
distinctive phrases like, “I am a gorilla” and “we have wrapping paper” being spoken amidst
some muffled conversation.
