Prosopagnosia and

1
Prosopagnosia and Face-Specific Mechanisms
Brad Duchaine Vision Sciences Laboratory Harvard
University http//www.faceblind.org
2
The nature of cognitive specializations
Domain-specificmechanisms specialized for
particular types of content. e.g.-speech,
faces.
Domain-generalmechanisms specialized for
particular processing tasks. e.g.-recognition,
reasoning.
3
Prosopagnosia Acquired Developmental
Long considered an extremely rare condition
www.faceblind.org contacted by 400 prosopagnosics
Majority are developmental
4
Living with Prosopagnosia
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.
I think prosopagnosia has worsened my current
depression, if its 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 cant confidently function
any other way. My avoidance of people
to interact with socially is nearly phobic.
5
Explanation in prosopagnosia
Face-Specific Mechanism
6
Case History Developmental Prosopagnosic
Edward

• 53-year-old right-handed man.
• Ph.D.s in physics and theology.

• Aware of problems as a child.
• Knows of no head trauma.
• MRI showed no abnormalities.

• General face processing impairment.
• Reports no difficulties with object recognition.
• No navigational difficulties.

7
Case History Acquired Prosopagnosic
LJ

• 16-year-old high school student.
• Incident at school dance.

• Knows of no head trauma.
• Incidents over last few years.

• Feels lonely in world devoid of facial
  information.
• Impairment beginning with face detection.

8
(No Transcript)
9
(No Transcript)
10
Case History Acquired Prosopagnosic
LJ

• 16-year-old high school student.
• Incident at school dance.

• Knows of no head trauma.
• Incidents over last few years.

• Feels lonely in world devoid of facial
  information.
• Impairment beginning with face detection.

• Reports normal object recognition.
• Navigational skills are deteriorating.
• CAT, MRI, and EEG are normal.

11
Edwards Face Recognition
Famous Face Recognition
Duchaine Nakayama (2004) Neuron
12
LJs Face Recognition
13
fMRI procedure
Localizer Block-design with 5 stimulus classes.
Faces Scenes
Bodies Objects Scrambled
14
FFA Faces - Objects
Controls
15
PPA Places - Objects
Controls
16
EBA Bodies - Objects
17
Repetition decrease in FFA
Signal Change to Face 2
Different Face
Same Face
Face 1
Face 2
Face 1
Face 2
18
Signal Change Same / Signal Change Diff
19
Explanations for prosopagnosia
A mechanism isnt working, but what is its domain?
20
Within-Class Mechanism
Mechanism for recognizing individual
items. (Damasio et al., 1982)
21
Within-Class Mechanism
22
(No Transcript)
23
(No Transcript)
24
Faces Individual Scores
A
25
(No Transcript)
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
Configural Processing Mechanism
Upright faces activate configural processing.
Face-specific? or General purpose?
Domain-general mechanism for configural
processing (Levine Calvanio, 1989)
30
Parts
Spacing
31
Spacing Changes Correct
Correct Part Changes
32
Configural Processing Mechanism
Demonstrates face-specific impairment.
33
Upright vs Inverted
34
Face Matching Upright versus Inverted
35
Face Matching Upright versus Inverted
Correct
Controls
Edward
LJ
36
Face Matching Upright versus Inverted
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
Verification
40
Naming
Naming
Scaled Correct
Session
41
Naming
Scaled Correct
Session
42
Individual Verification
Scaled Correct
Session
43
Individual Verification
Scaled Correct
Session
44
Family Verification
Correct
Session
45
Family Verification
Correct
Session
46
Rapid Expertise Mechanism
Results are inconsistent with hypothesis
47
Extended Expertise Mechanism
Mechanism for recognition of items from expert
categories (Diamond Carey, 1986)
48
Extended Expertise Mechanism
49
Extended Expertise Mechanism
50
Extended Expertise Mechanism
51
Alternative Explanation
Body Matching
Inverted Matching
Greeble Training
Old-New Tests
Part- Spacing
Within-Class Configural Processing Non-Decomposa
ble Curved Surfaces Rapid Expertise Extended
Expertise
52
Explanation in prosopagnosia
Face-Specific Mechanism
53
(No Transcript)
54
Mr. CKAgnosia without Prosopagnosia
(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 Edwards case
58
(No Transcript)
59
(No Transcript)
60
Poodle face palinopsia
61
Poodle face palinopsia
62
(No Transcript)
63
Expertise Criterion Comparable Verification RTs
Response Time (msec)
Session
64
Expertise Criterion Comparable Verification RTs
Response Time (msec)
Session
65
FFA Faces Objects
Control
Right
66
PPA Scenes - Objects
67
EBA Bodies - Objects
Control
EBA
Edward
68
(No Transcript)
69
Edward
Control
PPA
EBA
70
Imaging Results
Structural MRI showed no obvious abnormalities.
71
Cambridge Test of Face Memory
Duchaine Nakayama (under review)
Neuropsychologia
72
(No Transcript)
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
100
100
Ed
Tina
90
Gayle
Frank
Maureen
90
Dana
80
Joe
70
80
60
Correct
Correct (n 25)
50
Ed
Tina
Gayle
70
40
Frank
Maureen
Dana
30
Joe
60
20
10
50
0
Upright
Inverted
Famous Faces
Sequential Face Matching
75
Mr. CKAgnosia without Prosopagnosia
(Moscovitch et al., 1997)
76
Z values for NMs scores
-10 -8 -6 -4 -2 0 2 4 6
8 10
Face OIT Faces 1 Faces 2 Warrington Famous
Faces Profiles
Accuracy Response Time
Duchaine et al., 2003 Perception
77
Duchaine et al., 2003 Perception
78
(No Transcript)
79
Configural Processing Hypothesis
Predicts that Edward will be impaired.
80
Non-selective response to faces vs. objects
81
Problems with RT criterion
RT criterion is dependent on proportions of
different trial types. It says nothing
about proficiency. Past results show that RT
criterion does not work.
(Gauthier et al., 1998)
82
Greeble Transfer or Task Learning?
(Gauthier et al., 1998)
83
Putative holistic/configural effects are not
face-like

• No evidence of a large inversion effect.
• Part-whole difference between experts novices.
• Part-in-original vs. part-in-whole effects
• --Gauthier et al. (1998)No effects.
• --Gauthier et al. (2002)Two effects in
  opposite directions.
• Composite effect
• --Gauthier et al. (1997)No effect.
• --Gauthier et al. (1998)No effect.
• --Gauthier et al. (2002)No effect.

84
Low- and Mid-Level Vision
Are Edwards face processing impairments due to
problems with low-level or mid-level
vision? Visual acuity Near vision Normal Far
vision Corrected-to-normal Pelli-Robson
Contrast Sensitivity Test Normal Birmingham
Object Recognition Battery Length
match Normal Size match Normal Orientation
match Normal Position of gap match Normal
85
Paradigmatic ExamplesLanguage and Face
Recognition
ChomskyRules and Representations FodorModula
rity of Mind PinkerLanguage Instinct
CowieWhats within?
Bates et alRethinking Innateness
86
Remaining Hypotheses
Other than faces, no examples of classes for
which everyone has expertise.
Little evidence that expertise leads to face-like
processing.
Unclear how to test either hypothesis with Edward
or LJ.
87
Edward Normal inversion effect for face
detection
Low Density
High Density
Upright
88
(No Transcript)
89
Remaining Hypotheses Double Dissociation
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