Selective visual streaming in face recognition: evidence from developmental prosopagnosia.

Computational considerations suggest that efficient face identification requires the categorization and exclusive streaming of previously encoded face visual primitives into a dedicated face recognition system. Unique evidence supporting this claim is provided by a rare case of developmental pure prosopagnosia with otherwise normal visual and cognitive functions. Despite his normal visual memory and ability to describe faces, he is extremely impaired in face recognition. An early event related brain potential (N170) that is normally elicited exclusively by human faces, showed no specificity in this person. MRI revealed a smaller then normal right temporal lobe. These data emphasize the indispensability of the early streaming process for face recognition.