Prosopagnosia: a bihemispheric disorder.

A 54-year-old, right-handed male suffered three sequential infarcts. The first two destroyed much of the right posterior parietal area, the posterior-medial portion of the right temporal lobe and virtually the entire right occipital lobe producing left homonymous hemianopsia and left visual neglect but no prosopagnosia. A third vascular accident involved the left parieto-occipital lobe and immediately produced prosopagnosia that has persisted. The sequential correlations of lesion and symptomatology in this case demonstrate that development of persistent prosopagnosia occurred only after bilateral damage.