Slow habituation of induced gamma and beta oscillations in association with unreality experiences in schizotypy

Highly schizotypal individuals exhibit deficits in attentional processing, in particular dysfunctional habituation. This has led to the suggestion that abnormal habituation may represent a trait marker of psychotic vulnerability. This study examined the difference between high- and low-schizotypal individuals' habituation of nonphase-locked gamma and beta-1 oscillations, with and without attention. Measures of schizotypy were obtained from 40 participants and habituation to different tones was examined over trials of three interval lengths, under conditions of attention and inattention. The data showed that all participants habituated over trials with long intervals when attending to the stimuli. However, those participants who scored high on the unreality subscale exhibited significantly less habituation relative to those with low unreality scores for the short-interval trials. Furthermore, there was no difference in the orienting response to the initial stimuli between these subgroups. These results are discussed in terms of a dysfunctional rehearsal process influencing habituation for those with high-unreality scores.