An EEG study of visual attention in schizophrenic patients and normal controls.

This is a series of experiments examining the EEG, both at rest and in response to visual stimuli of varied complexity, in schizophrenics and normal controls. Subjects attended on several occasions. The resting EEG of patients was more activated than that of normals on all sessions, although only the patients showed diminished activation as a function of visits. The EEG of normals responded systematically on all occasions, but the patients showed similar response only under conditions of instructional set prescribing active stimulus appraisal. For both groups, subsequent stimulus recognition scores were correlated positively with EEG discrimination of stimuli during inspection. Within the patient group, several measures of pathology correlated both with recognition performance and several EEG parameters. Thus the present study draws together data demonstrating attentional deficit, heightened arousal, and reduced cortical variability in schizophrenics. Attention is drawn to methodological difficulties inherent in this type of study.