1. Prosopagnosia and Face-Specific Mechanisms Brad Duchaine Vision Sciences Laboratory Harvard University http://www.faceblind.org

2. The nature of cognitive specializations Domain-general—mechanisms specialized for particular processing tasks. e.g.-recognition, reasoning. Domain-specific—mechanisms specialized for particular types of content. e.g.-speech, faces.

3. Prosopagnosia: Acquired & Developmental www.faceblind.orgwww.faceblind.org contacted by 400 prosopagnosics Long considered an extremely rare condition Majority are developmental

4. “While traveling, I had a stopover at O'Hare and I was approached by a stranger in the lounge area. It took 10-15 seconds of casual conversation before realizing who it was. It was my brother.” Living with Prosopagnosia “I think prosopagnosia has worsened my current depression, if it’s not the root cause of it. This condition always affects my ability to form normal social links to others. I prefer to be a recluse because I can’t confidently function any other way. My avoidance of people to interact with socially is nearly phobic.”

5. Explanation in prosopagnosia Face-Specific Mechanism Within-Class Mechanism Configural Processing Mechanism Curvature Mechanism Non-Decomposable Mechanism Rapid Expertise Mechanism Extended Expertise Mechanism

6. Edward Case History: Developmental Prosopagnosic General face processing impairment. Reports no difficulties with object recognition. No navigational difficulties. Aware of problems as a child. Knows of no head trauma. MRI showed no abnormalities. 53-year-old right-handed man. Ph.D.s in physics and theology.

7. LJ Case History: Acquired Prosopagnosic Feels lonely in world devoid of facial information. Impairment beginning with face detection. Knows of no head trauma. Incidents over last few years. 16-year-old high school student. Incident at school dance.

10. LJ Case History: Acquired Prosopagnosic Feels lonely in world devoid of facial information. Impairment beginning with face detection. Knows of no head trauma. Incidents over last few years. 16-year-old high school student. Incident at school dance. Reports normal object recognition. Navigational skills are deteriorating. CAT, MRI, and EEG are normal.

11. Controls 25 faces 21.6 (2.5) Famous Face Recognition Edward’s Face Recognition Edward 3 Duchaine & Nakayama (2004) Neuron

12. LJ’s Face Recognition Famous Face Recognition 32 faces Controls 28.8 (3.2) 1 LJ

13. fMRI procedure Localizer: Block-design with 5 stimulus classes. Faces Scenes Bodies Objects Scrambled

14. Controls Edward LJ FFA: Faces - Objects

15. PPA: Places - Objects Controls Edward LJ

16. Control Edward LJ EBA: Bodies - Objects

17. % Signal Change to Face 2 Repetition decrease in FFA Face 1Face 2Face 1Face 2 Different FaceSame Face

18. % Signal Change Same / % Signal Change Diff

19. A mechanism isn’t working, but what is its domain? Explanations for prosopagnosia Predicted ImpairmentsProposed Domains Curved surfaces (Kosslyn et al., 1995; Laeng & Caviness, 2001) Within-class recognition (Damasio et al., 1982) Configural Information (Levine & Calvanio, 1989) Upright faces (Farah, 1996) Non-decomposable objects (Farah, 1991) Rapid Expert Classes (Gauthier et al., 1999) Extended Expert Classes (Carey & Diamond, 1986; Carey, 1992) ? ?

20. Mechanism for recognizing individual items. (Damasio et al., 1982) Within-Class Mechanism

21. Tools Landscapes Cars Houses Horses Guns Faces Sunglasses Within-Class Mechanism

24. Faces: Individual Scores A’

26. Response time z scores

27. Non-Decomposable Mechanism Mechanism for representing objects difficult to decompose into parts (Farah, 1991) May require holistic strategy. Hypothesis not explicit about what objects qualify.

28. Curvature Mechanism Mechanism for representing curved surfaces (Kosslyn et al., 1995; Laeng & Caviness, 2001). Laeng & Caviness (2001): Dogs, glasses, and cars.

29. Upright faces activate configural processing. Configural Processing Mechanism Domain-general mechanism for configural processing (Levine & Calvanio, 1989) Face-specific? or General purpose?

30. Parts Spacing Parts Spacing

31. Spacing Changes % Correct Part Changes Spacing Changes % Correct Part Changes

32. Configural Processing Mechanism Demonstrates face-specific impairment. Normal House spacing inconsistent with: Configural processing hypothesis Non-decomposable hypothesis

33. Upright vs Inverted Non-decomposable hypothesis Curvature hypothesis

34. Face Matching: Upright versus Inverted

35. Controls Face Matching: Upright versus Inverted EdwardLJ % Correct

36. Face Matching: Upright versus Inverted Curvature hypothesis Non-decomposable hypothesis Normal inverted performance inconsistent with: No special processing for upright faces. Edward processes upright and inverted faces similarly. LJ performs worse with upright faces than inverted faces. Upright representations sent to “black hole”.

37. Rapid Expertise Mechanism Mechanism for recognition of items from expert categories (Gauthier et al., 1997, 1999)

38. Rapid Expertise Mechanism Edward not a face expert after 53 years. LJ has lost his expertise with faces.

39. Rapid Expert Mechanism Eight sessions of training (Gauthier & Tarr, 2002). Sessions 1-4: Between 495-680 Test Trials Sessions 5-8: 180 Test Trials Verification Yes Triz No Naming T (for Triz)

40. Naming Scaled % Correct Session Naming

41. Session Scaled % Correct Naming

42. Scaled % Correct Session Individual Verification

43. Scaled % Correct Session Individual Verification

44. Session % Correct Family Verification

45. % Correct Family Verification Session

46. Rapid Expertise Mechanism Results are inconsistent with hypothesis Greeble results are inconsistent with: Within-class hypothesis (Damasio et al., 1982) Curvature hypothesis (Kosslyn et al., 1995; Laeng & Caviness, 2001)

47. Extended Expertise Mechanism Mechanism for recognition of items from expert categories (Diamond & Carey, 1986)

48. Extended Expertise Mechanism

51. Within-Class Configural Processing Non-Decomposable Curved Surfaces Rapid Expertise Extended Expertise Old-New Tests Part- Spacing Inverted Matching Greeble Training Body Matching XXXXXX XXXXXX XXXXXX XXXXXX XXXXXXXX Alternative Explanation

52. Explanation in prosopagnosia Face-Specific Mechanism Configural Processing Mechanism Within-Class Mechanism Curvature Mechanism Non-Decomposable Mechanism Rapid Expertise Mechanism Extended Expertise Mechanism

53. General-purpose “Richard Nixon?” “Richard Nixon” Face-specific

54. Mr. CK: Agnosia without Prosopagnosia CK cannot recognize objects CK can recognize faces Inverted faces (Moscovitch et al., 1997)

55. Faces, Domains, and Natural Categories Results strongly support existence of what have been called domain-specific mechanisms Domain-specificity and natural categories Specialization for a natural category

56. Developmental Inferences Edward never developed face-specific mechanisms. His behavioral and fMRI results show that he developed normal object recognition mechanisms. Functionally dissociable and developmentally dissociable.

57. Inferences from Edward’s case Mature Mechanisms Specific Developmental Mechanisms Faces General ObjectsPlaces Core Mechanisms

60. Poodle face palinopsia

63. Session Response Time (msec) Expertise Criterion: Comparable Verification RTs

64. Session Response Time (msec) Expertise Criterion: Comparable Verification RTs

65. FFA: Faces – Objects Edward Right Control Right FFA

66. PPA: Scenes - Objects Edward Right Control Right PPA

67. EBA: Bodies - Objects Control Edward EBA

68. Edward Right

69. PPA EBA EdwardControl

70. Structural MRI showed no obvious abnormalities. Imaging Results

71. Cambridge Test of Face Memory Examples Test item with identical images Test item with novel images Test item with novel images with noise Duchaine & Nakayama (under review) Neuropsychologia

72. Item Number Cumulative Score Introduction Novel imagesNovel images with noise

73. Future Directions Developmental Prosopagnosia Neural basis Dissecting face processing Etiology Genetic basis of face perception Autism & prosopagnosia Plasticity/Therapies Developmental Topographagnosia? Psychophysics Face recognition test Training with inverted faces Activation of face recognition

74. Rapid Expertise Hypothesis 50 60 70 80 90 100 UprightInverted Sequential Face Matching % Correct Ed Tina Gayle Frank Maureen Dana Joe 0 10 20 30 40 50 60 70 80 90 100 Famous Faces % Correct (n = 25) Ed Tina Gayle Frank Maureen Dana Joe

75. Mr. CK: Agnosia without Prosopagnosia CK cannot recognize objects CK can recognize faces Inverted faces (Moscovitch et al., 1997)

76. Face OIT Faces #1 Faces #2 Warrington Famous Faces Profiles -10 -8 -6 -4 -2 0 2 4 6 8 10 Accuracy Response Time Z values for NM’s scores Duchaine et al., 2003 Perception

77. Face OIT Faces #1 Faces #2 Warrington Famous Faces Profiles Emotion Hexagon Eyes Test Emotion Matching Emotional Intensity -10 -8 -6 -4 -2 0 2 4 6 8 10 Accuracy Response Time Z values for NM’s scores Duchaine et al., 2003 Perception

79. Configural Processing Hypothesis Predicts that Edward will be impaired. # Correct

80. Non-selective response to faces vs. objects Face - FixationObject - Fixation +-+-

81. RT criterion is dependent on proportions of different trial types. It says nothing about proficiency. Past results show that RT criterion does not work. 1 3 3 2 (Gauthier et al., 1998) Problems with RT criterion

82. (Gauthier et al., 1998) Greeble Transfer or Task Learning?

83. 1.No evidence of a large inversion effect. 2.Part-whole difference between experts & novices. 3.Part-in-original vs. part-in-whole effects: --Gauthier et al. (1998)—No effects. --Gauthier et al. (2002)—Two effects in opposite directions. 4.Composite effect: --Gauthier et al. (1997)—No effect. --Gauthier et al. (1998)—No effect. --Gauthier et al. (2002)—No effect. Putative holistic/configural effects are not face-like

84. Low- and Mid-Level Vision Are Edward’s face processing impairments due to problems with low-level or mid-level vision? Visual acuity Near visionNormal Far visionCorrected-to-normal Pelli-Robson Contrast Sensitivity TestNormal Birmingham Object Recognition Battery Length matchNormal Size matchNormal Orientation matchNormal Position of gap matchNormal

85. Paradigmatic Examples: Language and Face Recognition Chomsky—Rules and Representations Fodor—Modularity of Mind Pinker—Language Instinct Cowie—What’s within? Bates et al—Rethinking Innateness Language is a difficult test case. Face recognition more tractable ability.

86. Face-specific hypothesis (Farah, 1996; Moscovitch et al., 1997) Other than faces, no examples of classes for which everyone has expertise. Unclear how to test either hypothesis with Edward or LJ. Extended expertise hypothesis (Diamond & Carey, 1986; Carey, 1992) ? ? Remaining Hypotheses Little evidence that expertise leads to face-like processing.

87. Edward: Normal inversion effect for face detection Low Density High Density Upright Inverted

89. Remaining Hypotheses: Double Dissociation Mr. CK: Airplane & toy soldier expert (Moscovitch et al., 1997) RM: Car expert (Sergent & Signoret, 1992)

90. Remaining Hypotheses: Critical Period Face Configural Face configural processing does not develop without input during the first months of life. (Le Grand et al., 2001) No critical period for non-face expertise.

91. Remaining Hypotheses Face-specific Hypothesis (Farah, 1996; Moscovitch et al., 1997) Extended Expertise Hypothesis (Carey & Diamond, 1986; Carey, 1992) ? ?