VISUAL-SPATIAL LOCALIZATION BY PATIENTS WITH FRONTAL-LOBE LESIONS INVADING OR SPARING AREA-46

MONKEYS With unilateral principal sulcus (PS) lesions show a contralat eral deficit in localizing remembered targets, especially as the recal l interval is lengthened. We tested 20 patients with unilateral fronta l-lobe excisions that invaded (FI) or spared (FS) area 46 (putative ho mologue of PS) and 32 normal controls (NC) on a task where subjects ha d to indicate the location of a light dot either immediately, or after 30s, with or without interference. The FI group was worse than the NC group following both delay conditions. NC and FS groups differed only after interference. We concluded that area 46 is involved in recallin g the location of visual targets, but unlike the monkey, the deficit i s not restricted to a particular part of the visual field.