1. Arizona State University
Memory and Cognition
PSY 324
Topic: Visual Imagery
Dr. Ellen Campana
Arizona State University

2. Visual Imagery

3. What is Imagery? Think about the following questions….
How many windows are on front of where you live?
How is the furniture arranged in your bedroom?
Are an elephant’s ears rounded or pointy?
What does a pumpkin pie smell like?
You use mental imagery to answer these
Mental imagery = experiencing a sensory impression in the absence of sensory input

4. Uses of Imagery Creative process of music Sports Psychology
Paul McCartney’s “Yesterday”
Conductors use “inner audition” to practice without orchestras
Imagine sounds
Imagine locations of instruments
Sports Psychology
Swimming – imagining all of the strokes
Time to mentally rehearse linked to real times
Jack Nicklaus, golfing, discovered an error

5. Uses of Imagery
Visual Imagery (mental imagery of visual info) useful in scientific discoveries
Einstein’s theory of relativity came from imagining himself riding along a beam of light

6. The Study of Imagery Early ideas
Aristotle: thought is impossible without an image
Wundt: images are one of three basic elements of consciousness (others: sensations, feelings)
Strong link between images and thought
Gave rise to imageless-thought debate
Can people think without images?
Galton said yes: people who have difficulty forming images can still think
Wundt still said no

7. The Study of Imagery Behaviorism
Rise of behaviorism shut down the imageless-thought debate
Study of imagery is unproductive because visual images are invisible to everyone else
Watson (1928) called visual imagery “unproven” and “mythological”
1920’s-1950’s: no study of imagery in mainstream psychology

8. The Study of Imagery The Cognitive Revolution
Cognitive psychologists developed ways to measure behavior to infer cognitive processes (like visual imagery)
Memory (Paivio, 1963, 1965)
Mental chronometry (Shepard & Meltzer, 1971)
Study of imagery returned to mainstream psychology
Research continues today

9. Visual Imagery Research

10. Demonstrating that Imagery Exists
Paivio (1963, 1965): concrete vs. abstract nouns
Method: paired-associate learning
Training: participants learn pairs of words
Testing: participants presented with first word of pair, task is to recall the second (recognition task)
Two types of word pairs (within-Ss design)
Concrete: truck – tree (both easy to form image of)
Abstract: truth – idea (both hard to form image of)
Result: concrete pairs were easier to recall
Interpretation: Conceptual-peg hypothesis

11. Demonstrating that Imagery Exists
Shepard and Metzler (1971)
Mental chronometry – general idea of measuring how long it takes to carry out various cognitive tasks
Task: participants saw two objects, had to indicate quickly whether the two objects were the same or different
Results: Time it took to indicate that they were the same object was directly related to how far the object had to be rotated
Interpretation: imagery and perception share some of the same mechanisms

12. Shepard & Metzler (1971)

13. Imagery and Perception
Major question: do imagery and perception share the same mechanisms?
Kosslyn (1973): mental scanning
Task: Memorize an image, then answer questions about whether certain parts appear in the image
Time it takes to say yes is related to distance between initial focus and correct part

14. Kosslyn (1973)

15. Imagery and Perception
Major question: do imagery and perception share the same mechanisms?
Kosslyn (1973): mental scanning
Task: Memorize an image, then answer questions about whether certain parts appear in the image
Time it takes to say yes is related to distance between initial focus and correct part
Lea (1975): alternative explanation for result
Perhaps as people scan they are distracted by other parts
Kosslyn (1978): ruled out alternative explanation

16. Imagery and Perception

17. Imagery and Perception
Kosslyn’s experiments were convincing, but there was another alternative explanation
Pylyshyn (1973) – results are based on propositional mechanisms, not on spatial representation
Ushered in the imagery debate (still going on)

18. Propositional vs. Spatial
Basic idea: just because the experience is spatial doesn’t mean the underlying representation is
Spatial experience of mental images could be an epiphenomenon (side effect)
Epiphenomenon: related to / co-occurring with the mechanism, but not actually part of the mechanism
Information could be encoded with language (propositional representation) or with images (depective representations) – can’t tell
Propositional rep. is like a semantic network

19. Propositional vs Spatial

20. How Does Phlyshyn Explain Kosslyn’s First Set of Results?
Tacit-knowledge explanation
People in the mental scanning task behave based on what happens in a real scene (tacit knowledge)
In the real world it takes longer to travel greater distances
Simulate this behavior in the experiment
This explanation seems overly complicated and doesn’t seem to scale to complex scenes
Phylyshyn still makes these arguments, so they have to be addressed

21. Propositional vs Spatial

22. Against Propositional Representation
Finke and Pinker (1982)
Short presentation of simple display with 4 random dots, followed (after 2-sec delay) by an arrow
Participants had to say whether the arrow pointed to one of the dots in the first display (gone now)

23. Finke and Pinker (1982)

24. Against Propositional Representation
Finke and Pinker (1982)
Short presentation of simple display with 4 random dots, followed (after 2-sec delay) by an arrow
Participants had to say whether the arrow pointed to one of the dots in the first display (gone now)
Results: time it took to respond “yes” was directly related to distance from arrow
Why couldn’t this be propositional?
No time to convert to propositions, no meaning in the dots (except spatial relations)

25. Propositional vs. Spatial
Phylyshyn refuses to cede, responding to each study with tacit knowledge explanations
He is in the minority
Most researchers think there’s overwhelming evidence that mental imagery is spatial
Let’s assume (like most people) that mental imagery is spatial, and go on talking about how it relates to perception

26. Imagery and Perception

27. Size in the Visual Field
As you move closer to objects in the real world
Object fills more of your visual field
Details are easier to see
Kosslyn (1978) used these facts to investigate mental imagery

28. Size in Visual Field

29. Kosslyn (1978) Task Conditions (within-subjects)
Imagine two objects, moving close enough so that the bigger object fills most of visual field
Answer questions about one of the animals
Conditions (within-subjects)
Question about the animal when it was bigger than the other animal
Question about the animal when it was smaller than the other animal
Result: questions answered faster when it was bigger
Same as with a similar perceptual task

30. Kosslyn (1978)

31. Kosslyn (1978)
In addition to the question-answering experiment, participants did a mental walk task
Imagine an animal
Walk toward it until it “overflows” the visual field
How far away is it? (estimate distance)
Let’s try:
Cat
This building
Result: Greater distances for larger objects

32. Interactions Between Perception and Imagery
Visual images can interact with perception
Perky (1910) – subliminal presentation
Participants imagined an object and described their mental image to the experimenter
While they did this, an image of the same object was projected very dimly
No participants reported seeing the image
Descriptions of mental images matched details of real image
Farah (1985) – priming task
Mental images prime performance in a perception task

33. H Farah (1985) Imagine the letter ___
Indicate whether it was in the first or second white square H
Results: participants were more accurate when the letter that appeared matched the letter they had imagined

34. Imagery and the Brain

35. Brain’s Response to Imagery
Imagery neurons (Kreiman & coworkers, 2000)
Respond to both perceiving and imagining an object
Single cell recording, but in humans
fMRI & PET
most studies show overlap for perceiving and imagining (visual cortex, frontal lobes)
More activity toward the back of the brain for perception than imagery
Nonvisual areas deactivated (Amedi & coworkers, 2005)

36. Brain’s Response to Imagery
Transcranial Magnetic Stimuluation
Method for temporarily disrupting function in part of the brain
Lets researchers demonstrate causality, not just correlation (if you disrupt it and people can still do the task it cannot be causal)
Kosslyn and coworkers (1999) used this method to show that areas involved in both perception and imagery were causally linked to imagery (not an epiphenomenon)

37. Brain’s Response to Imagery
Neuropsychological case studies
Some evidence of related mechanism
MGS: mental imagery changed after removal of occipital lobe tissue
Perceptual problems accompanied by problems with imagery
Unilateral neglect (Map of part of Milan study)
Some evidence of independence
Dissociations between imagery and perception
R.M. Could see and draw but not imagine and draw, etc.
C.K. Visual agnosia (could not name pictures) but OK drawing from imagination

38. Putting it all Together
Some evidence for common mechanism BUT also some evidence for separate mechanisms
Behrmann & Coworkers (1994) have an account that brings them together (top-down vs. bottom-up)
No true “answer,” just continuing debate

39. Other stuff…

40. Using Images to Improve Memory
Method of Loci
“Placing” objects at places within a familiar location to remember them – walking through that location when remembering
Peg-word Technique
Learning a rhyme (one is a bun, two is a shoe…) and then imagining things you want to remember asssociated with those things

41. Mental Representation of Mechanical Systems
People can use visual imagery to solve problems
Five-gear problem
Water-pouring problem
Pulley problem
It has also been important for scientific discovery
Einstien’s theory of relativity

42. The End