Eight Reasons to Doubt the Existence of a Geometric Module

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 ones family
  against aggression, and so onLeda 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
.08
.31
.10
.39
.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
.96
.02
.57
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
Experiment 1
N 32
TRAINING (Between Subjects)
TESTING
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 lt 0.01)
• Geometric information guided reorientation in the
  small room
• Features guided reorientation in the larger room

LARGE ROOM TRAINING TESTING
SMALL ROOM TRAINING TESTING
E
G
E
.43 (.06)
G
.16 (.04)
0
0
.19 (.05)
.38 (.06)
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)

SMALL ROOM TRAINING/ LARGE ROOM TESTING
LARGE ROOM TRAINING/ SMALL ROOM TESTING
G
E
E
G
.10 (.04)
0
.03 (.02)
0
.94 (.03)
.03 (.02)
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 enoughbut
  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 processand 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
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 gt 50
• Can children use geometry in a figure without an
  axis of principal symmetry?
• YES if total GC choices gt 50
• Methodologically, have children been successfully
  disoriented?
• YES if correct choice NOT gt 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
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