Information processing deficits in anhedonia and perceptual aberration: a psychophysiological analysis

Building on recent reports of psychophysiological deviance in two groups believed to be at risk for psychosis, the present study sought to identify corresponding cognitive deviance in these groups. Subjects defined according to Chapman's questionnaires on physical anhedonia (n = 16) and perceptual aberration (n = 16) were tested in an auditory discrimination task while brain wave and autonomic activity was monitored. Although the discrimination performance of at-risk subjects equaled that of controls (n = 16), significant group differences occurred in event-related brain potential and heart rate responses. Interpreted within an information processing model of the discrimination task, these results suggest a deficit in the use of memory templates by anhedonics, for which they can compensate if given adequate stimulus input.