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Eight Reasons to Doubt the Existence of a Geometric Module

Eight Reasons to Doubt the Existence of a Geometric Module. Nora S. Newcombe Temple University. When Sociobiology Met Cognitive Psychology. Modular mind Adaptive pressure works to select specific mental abilities Massive modularity Core knowledge Innateness

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Eight Reasons to Doubt the Existence of a Geometric Module

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  1. Eight Reasons to Doubt the Existence of a Geometric Module Nora S. Newcombe Temple University

  2. When Sociobiology Met Cognitive Psychology • Modular mind • Adaptive pressure works to select specific mental abilities • Massive modularity • Core knowledge • Innateness • These evolutionarily-selected modules are (naturally) innately specified

  3. Swiss Army Knife Analogy • “The Swiss Army knife is a flexible tool [because] it is a bundle of tools, each well-designed for solving a different problem – scissors for cutting paper, corkscrew for opening wine, toothpick for cleaning teeth…..Similarly, the human mind … contains a large number of programs, each well-designed for solving a different adaptive problem: choosing a good mate, caring for children, foraging for food, avoiding predators, navigating a landscape, forming coalitions, trading, defending one’s family against aggression, and so on”—Leda Cosmides

  4. Innately-Specified Modules Have Proliferated • Language acquisition • Face processing • Theory of mind • Cheater detection • Geometric module

  5. What Do We Mean By Modularity? • Modular cognitive systems are domain specific, innately specified, hard wired, autonomous, and not assembled. • Fodor (1983, p. 37)

  6. Neural Specialization Does Not Entail Encapsulated Modularity • Brain areas generally need to ‘talk to’ one another to support a function

  7. Case Study of the Geometric Module • A representation of geometric information that guides reorientation following disorientation • That does NOT use nongeometric information even when doing so would be advantageous

  8. Hermer & Spelke (1996): Search Rates for Toddlers White Room F F C C .10 .39 .08 .31 .39 .12 .49 .12 R R N N C = Correct N = Near R = Reversal F = Far

  9. Hermer & Spelke: Search Rates for Adults White Room F F C C .02 .57 .96 0 .41 0 0 .04 R R N N C = Correct N = Near R = Reversal F = Far

  10. Language-as-Bridge Hypothesis • Adults may have a further system of representation that is uniquely human and that emerges over the course of development. This system may connect to many other systems of representation, regardless of their domain-specific content. Its operation may be governed by rules and principles allowing the arbitrary combination of information from distinct, domain-specific sources….The language faculty appears to have all the right properties to serve as this uniquely human combinatorial system of representation. --Hermer-Vazquez, Spelke & Katsnelson (1999, p. 34)

  11. Support for Role of Language • Transition to feature use at 6 years is correlated with productive use of left and right • Training left and right leads to feature use • Adults who do linguistic shadowing task concurrently do not use features

  12. Adaptive Combination Models • Various sources of spatial information • Ego-referenced: response learning and path integration • Allo-referenced: cue learning, place learning • Weighting depends on • Salience • Certainty and variability with which information is encoded • Validity • probabilities of finding objects given use of the information, derived from interaction with the environment • Weighting develops both in real time and in developmental time

  13. Point 1: Evidence Against Encapsulation from Non-Human Animals • Monkeys use colored walls and large but not small features (a sensible choice given likely cue validity) • Other species • Chickens • Pigeons • Fish • See Cheng & Newcombe, PBR 2005, for review

  14. Point 2: Featural Cues Are Only Neglected in Tiny Rooms Cheng & Newcombe (Psychonomic Bulletin & Review, 2005) Note: Perfect Performance = 100

  15. Point 3: Use of Features Varies for Several Reasons • Activity • Active motion focuses spatial attention • Active motion leads to remodeling of hippocampal firing • Nature of landmarks • More distal landmarks provide more useful and ecologically valid information • Larger landmarks may be more salient and more likely to be stable

  16. Room Within Room Studies • Small waist-high enclosure (Hermer-Spelke size) centered within “large” room (Learmonth et al. size) • Large room had one colored wall • Children stay within small enclosure Learmonth, Newcombe, Sheridan & Jones (Developmental Science, 2008)

  17. How the Data Fit An Adaptive Combination Model • Distal Action Target Proximal Age at Success • Feature? Possible? to Feature? Hermer-Spelke No No Yes 6 years Learmonth Yes Yes Yes 18 months et al. (earliest tested) Study 1 Yes No No 6 years Studies 2 & 3 Yes No Yes 4 years

  18. How the Data Fit An Adaptive Combination Model • Distal Action Target Proximal Age at Success • Feature? Possible? to Feature? Hermer-Spelke No No Yes 6 years Learmonth Yes Yes Yes 18 months et al. (earliest tested) Study 1 Yes No No 6 years Studies 2 & 3 Yes No Yes 4 years

  19. How the Data Fit An Adaptive Combination Model • Distal Action Target Proximal Age at Success • Feature? Possible? to Feature? Hermer-Spelke No No Yes 6 years Learmonth Yes Yes Yes 18 months et al. (earliest tested) Study 1 Yes No No 6 years Studies 2 & 3 Yes No Yes 4 years

  20. Point 4: Featural Cue Use is Easy to Get When Lacking Learmonth, Newcombe, Sheridan & Jones (Developmental Science, 2008) Similar finding: Twyman, Spetch & Friedman, (Developmental Psychology, 2007)

  21. * Point 5: Spatial as Well as Verbal Shadowing Reduces Feature Use in Adults Ratliff & Newcombe, Cognitive Psychology, 2007 Also--Hupbach et al., Spatial Cognition & Computation, 2007 F C .06 .52 .33 .10 R N Usual results with white room and with colored wall but no concurrent task

  22. Point 6: New Evidence from Conflict Paradigms • When features are moved, subjects must choose a location based either on features or on geometry • These paradigms reveal the fundamental similarity of human adults to children and non-human animals • Ratliff & Newcombe, Psychological Science, 2008

  23. Conflict Procedure “There are four hiding spots in this room, one at each corner”

  24. “I will hide a pair of keys in the same place every time”

  25. Conflict Procedure • 4 practice trials (target & landmark stable) • Leave the room • Brief delay ~ 2 minutes (drawing task) • While the participant waits outside, the experimenter goes back into the room to move the landmark clockwise to the next adjacent wall • Two conflict test trials

  26. Where are the keys? D A B C

  27. L Experiment 1 TRAINING (Between Subjects) TESTING N = 32 Indirect Landmark E G Small room (4x6ft) n = 8 Large room (8x12ft) n = 8 G L Direct Landmark Small room (4x6ft) n = 8 E G Large room (8x12ft) n = 8 G (Landmark = L, Geometrically appropriate = G, and Error = E)

  28. Adaptive Combination Predictions • When forced to choose one cue over the other (geometry vs. features), conflict test will result in a room size effect • Distal landmarks are more valid in the larger room • Corners related to feature cues will be more likely to be chosen in the larger room • Geometric cues are more salient in the smaller room • Geometric cues will be chosen most often in the smaller room

  29. Results • Significant Room Size effect (p < 0.01) • Geometric information guided reorientation in the small room • Features guided reorientation in the larger room SMALL ROOM TRAINING & TESTING LARGE ROOM TRAINING & TESTING E G E .43 (.06) G .16 (.04) 0 0 .38 (.06) .19 (.05) L G .56 (.06) .28 (.06) L G (Landmark = L, Geometrically appropriate = G, and Error = E)

  30. Experiment 2 • How does prior experience impact feature use in a conflict situation? • Replicates experiment 1 but switches room sizes between training and testing • Predictions: • Replicate no effect of landmark location (direct/indirect) • Training in the larger room will increase feature use among adults reorienting in the small room

  31. Results • Cross-experiment comparisons: • Significant effect of training • Feature use increased in small room testing from Exp. 1 (small room training) to Exp. 2 (large room training) LARGE ROOM TRAINING/ SMALL ROOM TESTING SMALL ROOM TRAINING/ LARGE ROOM TESTING G E E G .10 (.04) 0 .03 (.02) 0 .03 (.02) .94 (.03) L G .81 (.04) .10 (.04) G L (Landmark = L, Geometrically appropriate = G, and Error = E)

  32. Conclusions • Feature use is not associative: • No effect of feature location (direct vs. indirect) in Exp 1 or 2 • Experience is important • As expected, large room experience boosts feature use for the small room test • Reorientation depends on process of combining weights associated with features and geometry • Not simply relying on the most salient cue • Although the conflict procedure does not allow direct assessment of combination

  33. Point 7: Geometric Information May Be a Special Case of Relative Information • The modularity position predicts failure to reorient in the absence of geometric information • Is reorientation a more general discrimination of relative quantity task? Non-geometric, Relative Cue Non-relative Cues Huttenlocher and Lourenco, 2007

  34. Why Might Relative Cues Be Easiest? • Multiple cues • Area, spatial density, and number • Nominal versus ordinal scale • “Cues which specify order along a magnitude scale (more, less) may be more easily mapped onto spatial position (left, right) than two distinct unordered properties (red, blue) which are mapped separately onto spatial position” (Huttenlocher & Lourenco, 2007)

  35. Is This Pattern True Across Species? • Since the initial claims of modularity were made from animal research… • Will mice replicate this pattern of results?

  36. C57 mice – 4 per group Non-geometric Relative Cue Non-geometric Non-Relative Non-geometric Non-Relative

  37. Results: AccuracyTwyman, Newcombe & Gould, J. Comparative Psychology, in press Small - Large 81% Yellow - Blue 69% Dots - Gray 69% Even though there is a trend for the relative cue group to be more accurate, there were no significant differences between groups

  38. Results: Trials to CriterionTwyman, Newcombe & Gould, J. Comparative Psychology, in press Small versus Large 12 trials (0.00) Yellow versus Blue 38 trials (5.77) Dot versus Gray 33 trials (6.81) The small-large group learned the task significantly faster than either the yellow-blue or the dot-gray group.

  39. Point 8: Use of Features is NOT Merely Associative • One might have thought 7 points were enough—but the modularity theorists have a comeback--

  40. The Module Strikes Back • Lee, Shusterman & Spelke (2006) argue that— • Search behavior following disorientation depends on two distinct processes: a modular reorientation process…and an associative process that directly links landmarks to locations(p. 581)

  41. Return of the Jedi • Problems with Lee et al. • Small moveable landmarks • Defining quite small area • Alternative way to test the two step hypothesis • Use of colored wall in an octagon with alternating short and long sides to discriminate among 3 all white corners

  42. A D B C The Octagonal Space

  43. Photo of the Octagon

  44. Starting with An All-White Octagon • Questions • Can children use geometry in a more complex figure? • YES if total GC choices > 50% • Can children use geometry in a figure without an axis of principal symmetry? • YES if total GC choices > 50% • Methodologically, have children been successfully disoriented? • YES if correct choice NOT > average of other GC choices

  45. Data from All-White OctagonNewcombe et al., Developmental Science, in press • At left, we see that both 2- and 3-year-old children were reliably greater than chance in choosing geometrically correct corners • At right, we see a slight and non-reliable ability to choose the correct corner from among the 4 geometrically correct corners

  46. Data from Octagon with Colored WallNewcombe et al., Developmental Science, in press • At left, we see that both 3- and 5year-old children were reliably greater than chance in choosing geometrically correct corners • At right, we now see a reliable ability to choose the correct corner from among the 4 geometrically correct corners

  47. What About the Targets in All-White Corners? • Correct choices reliably greater than average of other GC corners • 35% versus 14% at 3 years • 38% versus 10% at 5 years • These data show that young children do in fact use features to reorient

  48. X X X Can Children Use Features ALONE?Newcombe et al., Developmental Science, in press Three Hiding Boxes Two Hiding Boxes On these 2 conditions, children averaged 50%, reliably greater than chance (33%) In this condition, children averaged 64%, reliably greater than chance (50%)

  49. Specific Conclusions • Strong evidence for coding of geometric information • Little evidence for an encapsulated geometric module or the role of language in puncturing it • Good evidence that different types of spatial information are routinely (though not invariably) combined • Combination process depends on • Cue salience • Encoding variability and certainty • Acquiring information on cue validity through action and experience

  50. General Conclusion • We can analyze spatial navigation and orientation as an evolved mental skill without postulating • Encapsulated modularity • Highly specific innate endowment

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