[Are the lesions responsible for prosopagnosia always bilateral?].

To localize the lesions responsible for prosopagnosia one must first consider how recent anatomico-physiological data have modified our view of the visual system: the visual cortex has been parceled into a mosaic of visual areas, each of them processing preferentially a particular feature (form, colour, movement); there is evidence of a face area in the monkey temporal lobe, and a new model of the inferior longitudinal fasciculus has been offered. It is currently accepted that face recognition deficits are due to bilateral occipito-temporal lesions, but in view of several recent reports in which the lesions were localized on CT or MRI one may doubt that these lesions are necessarily bilateral. In some cases a right unilateral lesion seemed to be sufficient to induce prosopagnosia.