Developmental Prosopagnosia, The Bruce-Young Model of Face Processing, & the Intriguing Cases of Dr. S and AB

… and Prof. Rader, Oliver Sachs, Jane Goodall, & about 1 in 20 people

Anatomy of a Case Study

Referring ProblemObservationsHistory*Test Results*Inferences concerning cognitive processes

The Case of Dr. S.•Has had trouble recognizing people her whole life; she came to see a neuropsychologist to have her “face blindness” analyzed

I met lots of people. I had very intense conversations and I didn’t recognize them, even though they had been helpful by giving me lifts… People don’t like not to be remembered. So I always say, ‘You beautiful ladies, I don’t recognize you; excuse me, have we met before?

•Has above average IQ as measured by the WAIS•Including non-verbal items

•Does not have trouble with basic perception (as measured by•The Benton et al. Line Orientation Task•The Mental Rotation Task

•Has a first cousin with a similar problem•Failed to recognize the neuropsychologist & mistook other blond women for her•Has trouble with geographical orientation (finding her way around)

•Very high verbal fluency

The Benton et al. Line Orientation Task

Dr. S’s performance = normal

Mooney Faces – judgments of sex and age

Face Tests

Dr. S’s performance = normal

Benton et al. Facial Recognition Test—matching an identical face in the same or different orientation

Performance of Dr. S. = normal

Warrington Recognition Memory Battery Face Section: 50 stimulus cards with unfamiliar faces of men The subject has to judge how pleasant each face is Each card is shown for 3 seconds

Immediately after seeing the 50 cards, the subject is shown cards with pairs of faces and has to say which appeared earlier

Dr. S’s performance = normal

Pictures of Famous Faces

1. Subject is shown faces and asked, “Do you know the name of this person?”

2. Subject is given a set of names and asked, “Do you know the occupation of this

person?”

The subject is also shown a set of faces and asked for each face, “Do you know the occupation of this person?”

Nancy Pelosi

Dr. S’s performance = poor when face is the stimulus

De Haan Test of Familiar Faces

Subject is shown a face and is asked, “Have you ever seen this face before?”

Dr. S’s performance = very poor for familiar faces

Bruce-Young Model of Face Processing

What’s wrong with Dr. S???Procedure: Consider the set of face tests and what the pattern of Dr. S’s performance tells us about the processing of each structure in the model

Structural encoding? Can she do the Benton Face Recognition Test?

Directed Visual Processing?Can she do the Mooney Face Test?

Face Recognition Units (FRUs) ?Can she do the Warrington Recognition Battery?

Person Identity Nodes (PINs) ?Can she give the occupation of someone froma face?

So is the problem with her PINs?

NO!!

How do we know?From the results of the de Haan test!!!

Dr. S has problems just judging whether she has seen someone before when she has!

So, her problem must lie with the FRUs

But then, why can she do the Warrington Recognition Battery with faces????