The Bernstein Center Freiburg

Informal Seminar
Rainer Stollhoff

Max Planck Institute for Mathematics in the Sciences
Leipzig, Germany

Modeling Prosopagnosia: Computational Theory and Experimental Investigations of a Deficit in Face Recognition
Wednesday, July 28, 2010

11:00 h sharp
Bernstein Center
1st floor
Prosopagnosia is a profound deficit in facial identification which can be either acquired due to brain damage or is present from birth, i.e. congenital. Normally, faces and objects are processed by different cortical systems, and the spatial separation underlies the selectivity of the deficit in acquired prosopagnosia. This separation is still present in congenital prosopagnosia (CP) and questions modular accounts of the deficit.

In this talk, I will present a computational model of CP that was derived from formal considerations, implemented in artificial neural network models of facial information encoding, and tested in experiments with CP subjects. The main hypothesis is that the deficit in CP is caused by a failure to obtain adequate descriptions of individual faces: A predisposition towards a reduced structural connectivity in visual cortical areas enforces descriptions of visual stimuli that lack the amount of detail necessary to distinguish a specific exemplar from its population, i.e. achieve a successful identification.

In contrast to previous models of acquired prosopagnosia, here, the developmental aspect of CP is incorporated explicitly into the model, quantitative arguments for a deficit that is task specific (identification) - and not necessarily domain specific (faces) - are provided for synthetic as well as real data (face images), and the model is validated empirically in experiments with CP subjects.
The talk is open to the public. Guests are cordially invited!