PROCESSING FRAGMENTED FORMS AND STRATEGIC CONTROL OF ORIENTING IN VISUAL NEGLECT

A single case study is reported of a patient with a right parietal les ion who showed: (1) clinical left neglect; (2) poor report of right-fi eld items in identifying bilateral simultaneously presented stimuli; a nd (3) particularly poor processing of fragmented forms within his lef t visual field. We suggest that, in this patient, neglect is related t o an impairment in orienting attention to contour information followin g his right-hemisphere lesion. This is exacerbated by the use of fragm ented forms, but can be overcome by strategic allocation of attention to the left under bilateral presentation conditions. Neglect of the le ft, and extinction for right-side stimuli, reflect unbalanced competit ion on the attentional orienting system due respectively to (1) poor p erceptual processing and (2) strategically attending to the left side of space.