Abstract
The ability of subjects to identify and reproduce brief temporal intervals is influenced by many factors; stimulus-, task- or subject-based. The current study examines the role the individual’s personality has upon their perception of short durations, and their metacognition of that percept. Undergraduate subjects (n=120) completed the OLIFE schizotypal personality questionnaire prior to performing a modified temporal-bisection task. In the task, subjects responded to two identical instantiations of a 4deg diameter sinusoidal grating, presented 4deg above fixation for 1.5secs in a rectangular temporal-envelope. They initiated presentation with a button-press, and released the button when they considered the stimulus to be half-way through (750msecs). Subjects were then asked to indicate their ‘most accurate estimate’ of the two intervals and given feedback for the latter half of the trials. The stimuli were either static or drifted, blocked into 100 stimulus pairs. From a group perspective there was a significant order effect whereby the first interval appeared to be shorter (and closer to veridical) than the second, although this effect reduced to insignificance when stimuli were drifted. Subjects had insight into their own performance, indicated by a reduced variance for the ‘best estimate’ compared to the ‘worst’ of the two; this difference increased with feedback. In terms of personality, the positive-psychotic subscales of the OLIFE were correlated with a reduced confidence in performance, but no actual performance difference, and a reduced ability to use feedback. Negative subscales only correlated with an increased ability to use the drift to improve performance. These data are explained in terms of an increased level of noise with increasing positive schizotypy having an effect upon precision rather than accuracy in the decision process. In a greater context, these data are also consistent with a fully-dimensional view of psychosis.
Meeting abstract presented at VSS 2015