Seventeen healthy normal volunteers performed three facial recognition
tasks while their cerebral blood flow was measured with PET: categorizing
faces according to gender, recognizing new faces, and recognizing familiar
faces. These tasks activated three different pathways: respectively, the
left inferior temporal lobe and left frontal cortex; a predominantly right
frontal-right parietal-left cerebellar network; and left lingual and left
and right fusiform gyri. These results suggest that humans use different
brain regions in performing these three routine daily activities. The
results are consistent with previous observations concerning organization
of extrastriate visual cortex in human and nonhuman primate lesion studies,
including studies of the unusual syndrome of prosopagnosia (loss of the
ability to recognize familiar faces with intact ability to recognize a face
as a face).Abstract Teaser