Visual orienting in schizophrenia.

Patients with schizophrenia demonstrate a variety of attentional impairments which have proven difficult to relate to specific neural systems. Posner et al. (1988) reported an asymmetric slowing of right visual field orienting in schizophrenia similar to that observed in patients with parietal lesions. We examined the visual orienting performance of 19 patients and controls using two different versions of the Posner paradigm. In overall ANOVAs we found main effects of group, cue condition, and delay interval. However, we did not observe any main effect of visual field or interactions involving visual field. There was some evidence of an asymmetric cost of invalid cues similar to those reported by Posner et al. The bulk of data suggests bilateral attentional deficits.