Chapter 7

1. Chapter 7 Joel Cooper University of Utah

2. Sketch (You have until 6:10) • Sketch a map of Salt Lake City • Label the following • Major shopping malls • Parks • Courthouse • Major business • Tourist attractions • Zoo • Interstates • Airport • River(s) and lakes

3. Today’s Lecture • Mental Maps • Mental Representation • Levels of Analysis • Dual-Code Theory • Propositional Theory • Functional Equivalence

4. Tversky (1993) • Cognitive maps: Internal representations of our physical environment, particularly centering on spatial relationships • More of a collage than map • Heuristics distort cognitive maps in a fairly systematic way

5. Creating Cognitive Maps • Humans gain increased spatial knowledge using three strategies • Landmark (environmental freatures) • Route-road (procedures to get to one place from another) • Survey (Estimating distances between landmarks -- Maplike)

6. 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

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

8. Encoding Processes • Acoustic • Visual • Semantic • Olfactory • Tactile LTM STM Encoding Retrieval Time

9. Mental Representation • Internal representation of environment that is spatial or visual in nature • May include representations from any sensory modality • May represent Non-existent items • Kosslyn proposes images are used to help solve certain types of problems • How many chairs are there in your house? • Do bunnies have whiskers?

10. Representation and Manipulation • Representation ≠ Reality • Evidence for representation • Memory • Manipulation • Imagination • Creation • Prediction • Observation What is the form of Mental Representation?

11. What is the form of Mental Representation? • Answer: It depends on your perspective. • Levels of Analysis (LOA) Subjective Experience -- Epiphenomenal Neuro-Chemical -- Physical

12. Models of Mental Representation • Dual Code Theory • Propositional Theory • Functional Equivalence • Neurological Evidence / Support Cognitive / Philosophical perspective

13. LOA and Mental Representation • Many ways (Levels) to describe mental representations • The myriad models may simply provide a description at a different LOA • Some account for the research better than others • Supported ≠ Correct • All Descriptions include a tradeoff between • Generality • Specificity

14. Cognitive Psychological Approach • Methods • Self report • Rationalist approach • Empirical support • Experiments • Neuropsychological studies

15. Dual Code Theory • Paivio (1971) • We use two codes to represent information • Analogue codes– (often image) shares some perceptual features • Verbal codes- arbitrary symbols to represent items • Two codes are linked

16. Representations of a Carpet Analog Representations Symbolic/Propositional representation Carpet, Rug

17. Analogue Code Analogous Some perceptual similarity Concrete Spatial Simultaneous access Symbolic Code Arbitrarily symbolic Abstract Categorical Sequential purveyor of information Analogues and Symbols

18. Evidence for Dual Code Theory • Concrete (potato, horse) vs. abstract words (justice, love) • Concrete better recall • Concluded for concrete (analog & verbal label) not abstract words

19. Additional Evidence for Dual Code • Visual information has different characteristics than verbal code • Visual/spatial with a visual spatial task = bad time sharing • Visual/spatial with a verbal/auditory task = good time sharing • Shows each type of code is affected by different manipulations

20. 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

21. Evidence for Dual Code Theory • Brooks (1968) cont. • Second group saw a sentence • Memorized it • Were asked to classify each word as a noun by indicating "yes" or "no" • Verbal task A bird in the hand is not in the bush

22. Evidence for Dual Code Theory • Brooks (1968) cont. • Participants were then asked to respond in one of two ways • Say “Yes” or “No” • Point to the answer “Yes or No” • Why was this important? Yes No

23. Evidence for Dual Code Theory • Brooks (1968) Results For letter task, RT was slower when pointing. For the sentence task, RT was slower for the verbal response. This provides evidence for two types of codes being used.

24. Evidence for Dual Code Theory • te Linde (1982) • Participants answered questions about word or picture pairs

25. te Linde (1982) Results

26. Lets Test Your Imagery Ability! • Form a mental image of this picture • Which of the pictures on the next slide are part of this picture?

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28. Try Again with Another Design • Form a mental image of this picture • Which of the pictures on the next slide are part of this picture?

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30. Carmichael, Hogan, & Walters (1932) • Participants were shown simple figures with one of two verbal labels Hourglass Or Table Sun or ship’s wheel

31. Carmichael, Hogan, & Walters (1932) Results • Later participants were asked to draw items seen • Participants distorted the images to fit the labels • Interpreted as the images may be stored as propositional information

32. Analogical Limitations • Inability to see parts has led some to support a propositional code rather than an analogical code • Demonstrates mental images are not always precise

33. Propositional Theory • Do not store in form of images or statements • Instead have a “generic” code that is called “propositional” • Stores the meaning of the concept • Create a verbal or visual code by transforming the propositional code Images Statements Proposition [Relationship between elements] ([Subject element], [Object element])

34. Propositional Representation • The furry mouse bit the cat who is now hiding underneath the table. • How many propositions? [Action, Bit] [(Mouse, Cat)] {The cat the mouse bit; The mouse bit the cat; The cat was bitten by the mouse} [Attribute] [(Furry, Mouse)] {The furry mouse, The mouse with furry, The The mouse that is furry, Fur covers the mouse} [Attribute [(Hide, Cat)]… [Spatial Relation, Under] [(Table, Cat)]…

35. Problems for Propositional Theory • Direct object manipulation • Unitary interpretation of ambiguous figures from memory

36. 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. Draw this shape. • 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. Draw this shape

37. Functional-Equivalency Hypothesis • First proposed by Shepard and Kosslyn • Mental images are internal representations that operate in a way that is analogous to the functioning of the perception of physical objects =

38. Functional Equivalence Finke, Pinker & Farah (1989) Suggested functional equivalence for: • Mental rotation • Image scaling • Image scanning

39. Mental Rotation • Shepard & Metzler (1971) • Subjects had to decide whether displays had two similar shapes • Some pairs were similar, but rotated to various degrees

41. Shepard & Metzler (1971) Results

42. Mental Imagery Studies Demonstrate • Active process • Response times are proportional to degree of rotation • Speed in 2D 3D • Images are “Mental Sculptures” =

43. Neuropsychological Evidence & Mental Imagery • Cohen & Kosslyn • Same brain areas are involved in perception and mental rotation • Support for functional-equivalence hypothesis

44. Image Scaling • 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 • Does the rabbit have whiskers? • Does the rabbit have ears? • Does the rabbit have a beak? • Reaction time to answer is measured

45. Image Scaling Judgments faster for rabbits next to smaller creatures (larger visual image)

46. Image Scaling (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

47. Image Scanning • Kosslyn (1983) • Memorize map • Later ask to scan image • Manipulate distance between items in scan • Hut to grasses • Lake to Hut • Measure reaction time

48. Image Scanning • Linear relationship between the distance to scan and actual reaction time of participants • 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

49. Demand Characteristics • Major criticisms of Kosslyn’s Research • 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

50. Demand Characteristics &Mental Scanning • Participants give the experimenters the pattern they expect • Intons-Peterson replicated research but mislead experimenters • 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