SELECTIVELY DISTRIBUTED-PROCESSING OF VISUAL OBJECT RECOGNITION IN THE TEMPORAL AND FRONTAL LOBES OF THE HUMAN BRAIN

Evoked potentials to visually driven cognitive tasks were recorded thr ough depth electrodes placed bilaterally within the amygdala, hippocam pus, midtemporal and inferotemporal cortex, and lateral frontal cortex of 6 epileptic patients. Task-related differential response patterns were used to identify the recording sites engaged by specific aspects of visual encoding, In this group of 6 patients, the amygdala was most frequently engaged in encoding the familiarity of faces; midtemporal and inferotemporal cortex, in encoding perceptual identity and object categorization; and lateral frontal cortex, in holding visual object i nformation in working memory. The two aspects of encoding that most fr equently engaged the hippocampal region were related to working memory and object categorization. The processing of complex visual knowledge is thus anatomically distributed but regionally specialized. These ex periments also showed that identical input and output parameters can e ngage different areas of the brain depending on the nature of the inst ructional set.