[Unilateral lesions of the periarcuate cortex in the monkey]

Subpial unilateral ablations of the postarcuate cortex (area 6) were performed in four macaque monkeys. After the operation the animals showed a tactile contralateral neglect and a visual neglect for stimuli presented in the space immediately around the contralateral hemiface, they tended to use the hand ipsilateral to the lesion and their mouth and face movements in response to contralateral stimuli were disorganized. No primary motor deficits were described. With time there was a marked recovery of the symptomatology, but the preference for using the ipsilateral hand and extinction of the contralateral stimuli were present until the animals' death. The deficits after the postarcuate cortex are discussed with reference to previous electrophysiological data.