Face processing is central to social interaction. We use faces to identify people, determine what they are feeling, what they are attending to, and trait judgments based on faces contribute to how we behave toward others (e.g., Is this person trustworthy? Attractive to me?). In the human brain, face recognition is mediated by a distributed cortical network that includes visual, limbic, and prefrontal areas. However, the nature of the computations underlying face processing and the function of the different areas contributing to face processing remain unclear. To better understand the computational and neural basis of face processing, we will carry out behavioral and neuroimaging studies with participants who have suffered brain damage that disrupts their ability to recognize faces. This condition is known as acquired prosopagnosia, and our lab has developed the world's largest database of participants with acquired prosopagnosia (N=20 and growing). These prosopagnosic participants have varied face perception impairments as well as varied damage to the face processing network. This project will advance our knowledge of face processing in individuals with normal face processing and will also be the first step toward the development of a classification system for acquired prosopagnosia. Such a classification system would be valuable, because different types of prosopagnosia are likely to be responsive to different types of interventions.
The primary objective of the current proposal is to test fundamental cognitive and neural predictions of two influential models of face. Previous studies investigating face perception in prosopagnosia have examined only a few abilities in small samples. The proposed project, in contrast, will investigate a wide range of face perception abilities in at least 20 patients drawn from the PI's prosopagnosia database (www.faceblind.org). The studies will address three primary aims. They will test and, if necessary, revise the cognitive structure of a broad model of face perception (Aim 1), test and revise a model of facial trait perception (Aim 2), and test the neural predictions of these two models (Aim 3). The proposed project will yield two main intellectual outcomes: evaluation of the face perception models and their revision as necessary, and a taxonomy of acquired prosopagnosia. Creation of a taxonomy of acquired prosopagnosia will be a major advance, because the current practice of grouping together different types of acquired prosopagnosia hampers efforts to understand the condition and develop rehabilitation methods. Media coverage of our findings is likely to increase public awareness of prosopagnosia. The face perception battery created will be made freely available as user-friendly programs that will be useful for both researchers and clinicians. Undergraduate researchers, many of whom are members of minorities under-represented in science, will get hands-on experience in this project.
