Effect of a concurrent stimulus on timing depends on level of schizotypy: Evidence from a visual and an auditory temporal bisection task

The ability to perceive time is central to cognition. However, the ability to judge durations accurately is impaired in schizophrenia and schizotypy. Conclusions about similar aetiology of both, are constrained by sparse empirical evidence. Two experiments – using the temporal bisection task – examined the impact of schizotypy on judgements for visual and auditory stimuli. A click train manipulation, known to influence durations was also included. The following findings emerged. First clicker increased the percentage of long responses irrespective of schizotypy level, but only for visual and not for auditory stimuli. Second , auditory durations were overestimated compared to visual durations. Third , high schizotypy showed a pattern consistent with a lengthening memory for the anchors. The results suggest there are differences in perception of durations among low and high schizotypy –low schizotypals overestimate durations, indicative of the pacemaker component. The pattern of duration judgments of high schizotypals is compatible with a lengthening distortion in memory for standard durations of auditory stimuli – the auditory anchors seem to be lengthened compared to the visual anchors, for high schizotypals. Results from high schizotypals accord with previous evidence from those suffering from schizophrenia suggesting a similar pattern of distortion in time perception in schizophrenia and schizotypy.