Neurophysiological evaluation of sensory gating and selective attention in schizotypal personality

Current debate centres around the question of whether schizotypal personality is part of a spectrum of schizophrenia-related disorders. Investigations of biological markers for schizophrenia in schizotypal subjects have tried to test this relationship. Given that there is considerable evidence for both sensory gating and binaural selective attention abnormalities in schizophrenia, as reflected by event-related potentials (ERP), these attention and preattention mechanisms were investigated in students scoring in the top (n = 11) and bottom (n = 12) 10% of scores on the Schizotypal Personality Questionnaire (Raine, 1991). Groups were matched for age, gender composition, handedness and education. Results failed to reveal group differences in suppression of the P50 in the sensory gating task, suggesting that preattentive gating is not disturbed. In contrast, on the selective attention task, predicted patterns of ERP differences were generally found. The schizotypal group was characterized by hyperarousal as indexed by shorter latencies of most ERP components, selective dishabituation of the orienting response to the rare salient stimuli, response-set deficits, intrusion effects, as well as large post-response cognitive processing of stimuli. Results were consistent with ERP abnormalities found in schizophrenics with florid and low formal thought disorders