Human Cognitive
Processes: psyc 345
Ch. 4: Attention
Takashi Yamauchi
© Takashi Yamauchi (Dept. of Psychology, Texas A&M University)
Questions
• (Q1) How does attention work?
• (Q2) Under what conditions can we pay
attention to more than one thing at a time?
• (Q3) How are attention and visual
perception related?
Attention and Autism
• Impaired social interaction and communication
– Often fail to understand what other people think.
• Far more autistic boys than autistic girls (4:1)
• Overrepresented in children whose parents / grand
parents are engineers
– (Baron-Cohen et al.; Autism, 1997, 1, 153-163)
• substantial genetic component
• Video clip
– Invisible wall
– Autism and symptoms (3:56)
• http://www.youtube.com/watch?v=FuWWie1DlJY
Attention and Autism
Eye movement:
normal (white
markers) vs. autistic
viewers (black
markers)
“neuroenhancing drugs”
• http://www.newyorker.com/reporting/2009/
04/27/090427fa_fact_talbot
• A young man I’ll call Alex recently graduated
from Harvard. As a history major, Alex wrote
about a dozen papers a semester. He also ran a
student organization, for which he often worked
more than forty hours a week; when he wasn’t on
the job, he had classes. Weeknights were devoted
to all the schoolwork that he couldn’t finish during
the day, and weekend nights were spent drinking
with friends and going to dance parties. “Trite as it
sounds,” he told me, it seemed important to
“maybe appreciate my own youth.” Since, in
essence, this life was impossible, Alex began
taking Adderall to make it possible.
Adderall, a stimulant composed of mixed amphetamine
salts, is commonly prescribed for children and adults who
have been given a diagnosis of attention-deficit
hyperactivity disorder. But in recent years Adderall and
Ritalin, another stimulant, have been adopted as cognitive
enhancers: drugs that high-functioning, overcommitted
people take to become higher-functioning and more
overcommitted.
During his college years, Alex took fifteen milligrams of
Adderall most evenings, usually after dinner,
guaranteeing that he would maintain intense focus while
losing “any ability to sleep for approximately eight to
ten hours.”
Attention
• Video demonstration
• Change blindness
– http://viscog.beckman.illinois.edu/flashmovie/1
2.php
– http://viscog.beckman.illinois.edu/flashmovie/1
0.php
Attention
• Process of concentrating on specific
features of the environment, or on
certain thoughts or activities
– Excluding other features of the
environment
Mechanism of attention
• (Q1) How does attention work?
• Show me your models.
• Selective attention
• Divided attention (e.g., multi-tasking)
• Visual attention
Selective Attention
• How does it happen?
• How do you characterize the
mechanism of selective attention?
– What would be a good metaphor to describe
selective attention?
Selective Attention
• Ability to focus on one message and
ignore all others
– Research method: dichotic listening
• One message is presented to the left ear
and another to the right ear
• Participant “shadows” one message to
ensure he is attending to that message
Dichotic listening method
In the shadowing procedure, a person repeats out
loud words they have just heard.
But they are required to shadow only the attended
message (the message given to his left ear) and
ignore the unattended message (the message given
to his right ear).
Selective Attention
• Results of dichotic listening
– Participants could not report the
content of the message in unattended
ear
Broadbent’s filter model of attention.
• Sensory memory
– Holds all incoming information for a
fraction of a second
– Transfers all information to next stage
• Filter
– Identifies attended message based on physical
characteristics
– Only attended message is passed on to the next
stage
• Detector
– Processes all information to determine higherlevel characteristics of the message
Broadbent’s Filter Model
• Early-selection model
– Filters message before incoming
information is analyzed for meaning
Verifying Broadbent’s filter model
• Broadbent’s (1958) “split-scan”
experiment
Two letters were presented to two
ears at the same time
M
H
R
S
W P
Condition 1: subjects were asked
to report the letters in any order
Two letters were presented to two
ears at the same time
M
H
R
S
W P
Condition 2: subjects were asked
to report pairs of letters in the
order each pair was presented.
Results
Condition 1: subjects were asked
to report the letters in any order
M
H
R
S
Accuracy  65%
Subjects tended to report all
letters presented to one ear
(MRW) and then to the other
ear (HSP)
W P
Condition 2: subjects were asked
to report pairs of letters in the
order each pair was presented.
Accuracy  20%
• Broadbent’s (1958) “split-scan”
experiment
– Easy: report information from one ear
and then the other
– Hard: Switching back and forth
between ears
– It is difficult to switch attention
between ears
“Cocktail party phenomenon”
– You are in a cocktail party.
– You are talking with someone intently.
– Somewhere, someone else mentions
your name.
– You notice that even though your
attention is fully committed to the
person you were talking with.
• Ss were asked to shadow
the message received to
the left ear only.
• Left ear:
– Dear 7 Jane
• Right ear:
– 9 Aunt 6
• Shadowing report
– Dear Aunt Jane
Treisman’s attenuation model of selective
attention.
Tresiman’s Attenuation
Theory
• Intermediate-selection model
– Attended message can be separated
from unattended message early in the
information-processing system
– Selection can also occur later
Task load and selective attention
• Attention is more like resources
– Kahneman’s (1973) capacity theory
– When a particular task demands lots of processing
resources, then other tasks get fewer resources.
No task
Hard task
Attention capacity
Easy task
Attention blink
• CogLab Attention blink
• (10 min)
• Attention blink: DVD
• (Q2) Under what conditions can we pay
attention to more than one thing at a time?
Divided Attention
• Practice enables people to simultaneously
do two things which at first were difficult
– E.g., driving and singing
• After hours of practice, you can drive and
sing.
• How does that happen?
• What makes a task(s) automatic?
• If you can transferring task information
from short term memory to long term
memory, you can make the task automatic.
Divided Attention
• Schneider and Shiffrin (1977)
– Divide attention between remembering
target and monitoring rapidly
presented stimuli
• Memory set: 1-4 target characters
• Test frames: could contain random dot
patterns, a target, distractors
Caption: Consistent mapping condition for Schneider and Shiffrin’s (1977)
experiment.
Caption: Improvement in performance with practice in Schneider and Schiffrin’s
(1977) experiment. The arrow indicates the point at which participants reported
that the task had become automatic. This is the result of experiments in which
there were four target stimuli in the memory set and two stimuli in each frame.
Divided Attention
• Consistent mapping condition: target would
be numbers, and distractors would be letters
• Over time, participants became able to
divide their attention
• Automatic processing occurs without
intention and only uses some of a person’s
cognitive resources
Divided Attention
• Stroop effect
– Name of the word interferes with the ability to
name the ink color
– Cannot avoid paying attention to the meanings
of the words
Caption: Varied mapping condition for Schneider and Shiffrin’s (1977) experiment. This is
more difficult than the consistent mapping condition because all the characters are letters and
also because a character that was a distractor on one trial (like the T) can become a target on
another trial, and a character that was in the memory set on one trial (like the P) can become a
distractor on another trial.
Divided Attention
• Schneider and Shiffrin (1977)
– Varied mapping condition: rules changed from
trial to trail
– Over time, participants never achieved
automatic processing
Divided Attention
• Controlled processing: participants paid
close attention, and their search was slow
and controlled
%
correct
Caption: Comparing performance on the consistent and varied mapping tasks. Note that the
horizontal axis indicates the duration of each target frame. These graphs show that frames
must be presented for longer durations to achieve good performance in the varied mapping
condition.
• Controlled processing: participants
paid close attention and their search
was slow and controlled
• Strayer and Johnston (2001)
– Simulated driving task
– Participants on cell phone missed twice
as many red lights and took longer to
apply the breaks
• Same result using “hands-free” cell phone
Divided Attention
• 100-Car Naturalistic Driving Study
– Risk of accident is four times higher
when using a cell phone
• (Q3) How are attention and visual
perception related?
Attention and Visual Perception
• Inattentional blindness: a stimulus that is
not attended is not perceived, even though a
person might be looking directly at it
– Video: the mind’s eye,
• attention blink (Ch. 9-10)
Attention and Visual Perception
• Change blindness: if shown two versions of
a picture, differences between them are not
immediately apparent.
– http://viscog.beckman.illinois.edu/flashmovie/1
1.php
Visual Attention
• Visual attention and eye movement
• Eye tracker
• Eye tracking machine and demo
– http://www.youtube.com/watch?v=lGehsY7pcrc
• Attention helps select information.
• This is necessary because of the way the eye is
structured.
– Most cones reside around the fovea.
– To get accurate information about a scene, we need to
select carefully particular parts of the scene.
Attention and Visual
Processing
• Saccades – rapid movements of the
eyes from one place to another
• Fixations – short pauses on points of
interest
• Studied by using an eye tracker
Binding problem
• Visual features are assessed in a piece-meal
fashion.
• How do you integrate those?
Caption: Steps in Treisman’s feature integration theory. Objects are analyzed
into their features in the preattentive stage, and then the features are
combined later with the aid of attention.
Feature Integration Theory (FIT)
• Preattentive stage
–
–
–
–
Automatic
No effort or attention
Unaware of process
Object analyzed into features
• Focused attention stage
– Attention plays key role
– Features are combined
Feature Integration Theory (FIT)
• Treisman and Schmidt (1982)
– Ignore black numbers and focus on objects
– Report what you saw at each of the 4 locations
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61
ch 6
62
ch 6
63
Illusionary conjunctions
• We tend to put different features from
different objects together.
• brain damaged patients (parietal lobe) show
illusionary conjunctions even when they
view the stimuli for 10 seconds.
ch 6
64
Unilateral neglect
Copies of the black (A)
and
the white (B) vertical
contour.
Copies of the black (A)
and
the white (B) diagonal
contour.
• Video Clip
– Unilateral neglect (The Mind Eye)
Additional materials
Attention and Visual
Processing
• Stimulus salience – areas which
stand out and attract attention
– Bottom-up process
• Scene schema
– Top-down process
Attention (executive function)
• Planning
• Rational thinking
• Controlling one’s emotion
Posner, M. I., Rothbart, M. K. (2007) Research on Attention networks as a model
for the integration of psychological science. Annual Review of Psychology, 58,
1-23.
Read aloud each word
Green
Yellow
Red
Orange
Blue
Violet
Red
Yellow
Green
Raven test: (Carpenter, Just, &
Shell, 1990)
Attention revisited
• Human
– Executive control
– Metacognitive ability (controlling your own
attention / cognition) and deploying your
cognitive resources to achieve goals.