Impaired configurational processing in a case of progressive prosopagnosia associated with predominant right temporal lobe atrophy.

F.G., a 71-year-old right-handed man, presented with a slowly progressive deterioration in his ability to recognize faces of familiar and famous persons, contrasting with the relative preservation of other cognitive domains. His primary face perception skills were intact. Along with his face-recognition deficit, F.G. also exhibited a mild visual agnosia. A more detailed analysis of his performance on visuoperceptual tests revealed a selective deficit in retrieving the configurational representation of complex visual entities and an over-reliance on analysing individual features. Quantitative volumetric measurements of his temporal lobe structures showed a prevalent atrophy of the right fusiform gyrus and parahippocampal cortex. The results of the present study suggest that a right temporal variant of frontotemporal lobar degeneration may be characterized over a period of several years by an impaired configurational processing of visually complex entities in the absence of any semantic deficit.