Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Cognitive Psychologists Study Mental
Representations
•
Methods
– Self report
– Rationalist approach
– Empirical support
•
Experiments
•
Neuropsychological studies

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Mental Imagery
•
Internal representation of items that are not currently being sensed
– May be old, new, futuristic, imaginary
– May involve any of the sensory modalities
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Imagine a taste, a sight, a touch
– Majority of research on Visual Imagery

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Mental Imagery
•
Kosslyn proposes images are used to help solve certain types of problems
– How many chairs are there in your house?
– Do bunnies have whiskers?

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Dual Code Theory
•
Paivio (1971)
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We use two codes to represent information
– Image codes- analogue codes, shares some perceptual features
– Symbolic codes- arbitrary symbols to represent items (e.g., words)
– Two codes are linked

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Evidence for Dual Code Theory
•
Paivio compared concrete words
(potato, horse) with abstract words
(justice, love)
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Found participants were better able to recall concrete words
•
Concluded that dual code was created for concrete words (analog & verbal label) but not for abstract words

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Visual Codes are Processed
Differently than Symbolic Codes
– Visual information interferes with spatial information
– Verbal labels interfere with spoken words
– Sequence matters more for words, not so much for unrelated images
– Thus, each type of code is affected by different manipulations

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Evidence for Dual Code Theory
•
Brooks (1968)
– One group saw a block diagram of a letter
– Memorized it
– Were asked to mentally travel the letter and indicate if the corner was on the extreme top or bottom
Start

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Evidence for Dual Code Theory
•
Brooks (1968) cont.
– Second group saw a sentence
– Memorized it A bird in the hand is not in the bush
– Were asked to classify each word as a noun by indicating "yes" or
"no"
– Verbal task

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Evidence for Dual Code Theory
•
Brooks (1968) cont.
•
Participants were then asked to respond in one
Yes
No Yes
No of two ways Yes No
– Say “Yes” or “No” Yes No
– Point to the answer “Yes or No”
Yes
No Yes
No
– Why was this important?

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Evidence for Dual Code Theory
•
Brooks (1968) Results
Task Verbal Pointing
Letter Diagrams
11.3 sec.
28.2 sec.
Sentences
13.8 sec.
9.8 sec.
For image task, RT was slower when pointing.
For the symbolic task, RT was slower for the verbal response.
Different pattern = different processing for different codes

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Evidence for Dual Code Theory
• te Linde (1982)
•
Participants answered questions about word or picture pairs
Question Word Stimuli Picture Stimuli
Associated?
Mouse-Cheese
Similar size?
Thimble-Acorn

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1000
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Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7 te Linde (1982) Results
Words
Pictures
Association
Decision
Size

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Propositional Theory
•
Do not store in form of images
•
Instead have a “generic” code that is called “propositional”
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Stores the meaning of the concept
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Create a verbal or visual code by transforming the propositional code

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Propositional Representations

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Test Your Visual Imagery Ability!
•
Form a mental image of this picture
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Which of the pictures on the next slide are part of this picture?

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Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
2
4

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Try Again with Another Design
•
Form a mental image of this picture
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Which of the pictures on the next slide are part of this picture?

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Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
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4

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Carmichael, Hogan, & Walters (1932)
•
Participants were shown simple figures with one of two verbal labels
Sun or ship’s wheel
Hourglass
Or
Table

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Carmichael, Hogan, & Walters
(1932) Results

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Carmichael, Hogan, & Walters (1932)
Results
•
Later participants were asked to draw items seen
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Participants distorted the images to fit the labels
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This pattern supports the idea that images may be stored propositionally not as original analog image

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Analogical Limitations
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Inability to see parts has led some to support a propositional code rather than an analogical code
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Demonstrates mental images are not always precise

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Finke, Pinker & Farah (1989)
•
Imagine a capital letter D. Rotate the figure
90 degrees to the left. Now place a capital letter J at the bottom
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Imagine a capital letter N. Connect a diagonal line from the top right corner to the bottom left corner. Now rotate the figure 90 degrees to the right
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Demonstrates that participants could manipulate images

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Mental Imagery
•
Shepard & Metzler
(1971)
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Subjects had to decide whether displays had two similar shapes
•
Some pairs were similar, but rotated to various degrees

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Shepard & Metzler (1971) Results

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Mental Imagery Studies Demonstrate
•
Active process
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Response times are proportional to degree of rotation
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People can rotate images in threedimensional space as easily as twodimensional space
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Images are “Mental Sculptures”

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Functional-Equivalency Hypothesis
•
First proposed by Shepard and Kosslyn
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Mental images are internal representations that operate in a way that is analogous to the functioning of the perception of physical objects

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Neuropsychological Evidence & Mental
Imagery
•
Cohen & Kosslyn
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Same brain areas are involved in perception and mental rotation
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Support for functional-equivalence hypothesis

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Functional-Equivalence Evidence
•
Kosslyn (1975)
– Examine how participants scan and use images
– Some participants imagine an elephant next to a rabbit
– Others imagine a rabbit next to a fly
– Then answer questions about the rabbit
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Does the rabbit have whiskers?
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Does the rabbit have ears?
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Does the rabbit have a beak?
– Reaction time to answer is measured

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Kosslyn (1976)
•
Asked college students and fourth graders simple questions about animals
– Does a cat have claws?
– Does a cat have a head?
•
Varied the type of instructions used to answer questions
– Imagery instructions
– No imagery

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Kosslyn (1976) Results
•
In imagery condition, questions were answered faster if the attribute was larger
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In no imagery condition, questions were answered faster based on distinctiveness of characteristic for the animal, no impact of size

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Size Judgments (Moyer, 1973)
•
Which is larger, moose or roach?
•
Which is larger, wolf or lion?
– When objects are similar in size, participants imagine both objects and then compare the size of the objects in their image
– Similar results when making comparisons of actual physical objects
– The closer in size, the longer the reaction time

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Functional-Equivalence Evidence
•
Kosslyn (1983)
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Memorize map
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Later ask to scan image
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Manipulate distance between items in scan
– Hut to grasses
– Lake to Hut
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Measure reaction time

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Kosslyn (1983) Results
•
Linear relationship between the distance to scan and actual reaction time of participants
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Further support for functional-equivalence hypothesis
– Mental images are internal representations that operate in a way that is analogous to the functioning of the perception of physical objects

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Finke (1989) on Functional Equivalence
•
We use similar transformation on objects and mental images
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Spatial arrangements of a mental image are similar to spatial arrangements of actual object
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Images can be used to generate information not explicitly stored during encoding
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Processes of visual system are used on both mental images and visual objects

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Demand Characteristics
•
Major criticisms of Kosslyn’s Research
– Pylyshyn
– There is only one code, propositional
– The results due to task demands
– The instructions imply some necessary relationship between the physical distance and time required

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Demand Characteristics & Mental
Scanning
•
Participants give the experimenters the pattern they expect
– Intons-Peterson replicated research but mislead experimenters
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If experimenter expectations are part of demand characteristics, then leading them to believe that longer distances would lead to faster responding should alter the results
•
Evidence was found to support demand characteristics idea

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Demand Characteristics & Mental
Scanning
•
Jolicoeur & Kosslyn (1985)
– Created a false demand characteristic for a U shaped function for participants
– Proposed that Gestalt principle of proximity makes close points “hard”, and distant points would also take longer
– No experimental expectancy effect found
– Supports idea that image is being used

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Johnson-Laird (1983)
•
Proposed there are three types of mental representations
–
Propositional representations which are pieces of information resembling natural language
–
Mental models which are structural analogies of the world
– Mental imagery which are perceptual models from a particular point of view

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Characteristics of a Mental Model
•
A representation of a described situation rather than a representation of a text itself or the propositions conveyed by a text
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The structure corresponds to the functional relations among entities as they would exist in the world
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A simulation of events in the world, either real or imaginary

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Evidence for Mental Models
•
Kerr (1983)
– Studied participants who were blind
– Created a tactile Kosslyn Map study equivalent
– Participants had to study the island, given a physical map to touch
– Asked the same scanning questions
– Found the same pattern of results—longer distances, longer reaction times

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Visual Imagery & Spatial Imagery
•
Visual Imagery (images are visual)
– Seeing colors
– Comparing shapes
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Spatial Imagery (analog spatial format)
– Rotating objects
– Aiming and shooting at a target

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Neuroscience Evidence
•
Farah (1988)
– Brain Injury Case Study (L.H.)
– Gave some visual tasks
•
Color identification, object naming
– Gave some imagery tasks
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Mental rotation, mental scanning

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Farah (1988) Results
•
L.H.
– Poor visual image skill
– Normal spatial image skill
•
Thus, both types of imagery must exist

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
In Sum, Researchers Have Proposed
•
Evidence for analog codes
•
Evidence for propositional codes
•
Evidence for mental models
•
Evidence for a mental imagery that is spatial
•
Evidence for mental imagery that is visual

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Cognitive Maps: Historically
•
Tolman – Rats
• von Frisch – Bees
•
Thorndyke – Humans

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Creating Cognitive Maps
•
Gain increased spatial knowledge
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Using three types of knowledge
– Landmark (special buildings)
– Route-road (procedures to get to one place from another)
– Survey (global map-like view)

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Tversky (1993)
•
Cognitive maps more like cognitive collages
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Constructionist view of creating cognitive maps
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Distortions can occur when using heuristics

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Heuristics Affecting Cognitive Maps
•
Rotation heuristic
– Tend to ‘regularize’ tilted landmarks in maps to appropriate E-W or N-S axis
•
Alignment heuristic
– Students view two maps of the Americas
– One a correct map, and a second map which was altered (South America was moved westward with respect to North America)
– A majority of students thought the altered map was the correct one

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Heuristics Affecting Cognitive Maps
•
Density Heuristic
– More landmarks between two points, the greater the distance we estimate
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Right angle bias
– Streets are drawn at 90-degree angles (even when they are not)
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Symmetry heuristic
– Irregular geographic boundaries are made regular (e.g., Americans straighten out the
Canadian border)

Cognitive Psychology, Fifth Edition, Robert J. Sternberg
Chapter 7
Creating Maps from Text
•
Tversky
– What impact does the perspective of participant versus observer play in creation of a code
•
As a participant, emphasize propositional code
•
As an observer, emphasize perceptual code
– Findings indicate both play a role