Further observations on the nature of prosopagnosia.

Two new cases of prosopagnosia are described and compared with pertinent clinical material from the English language literature. The interpretation of this disorder most compatible with the clinical data appears to us to be that there is an underspecification of visuoperceptive information preventing both the formation of significant face images and the retrieval of well-known face memoranda existing within a relatively intact visual remote memory store. Failure of formation of immediate memoranda of similarly complex visual images is also commonly observed but does not seem to be a requirement for the symptom of prosopagnosia. Conceptualizing this abnormality as simply a material specific visual agnosia of images beyond the classifier level would still appear to be acceptable if less informative.