Abstract
The ability of subjects to identify and reproduce brief temporal intervals is influenced by many factors whether stimulus-, task- or subject-based. Previously we have shown the effects of personality on sub-second timing judgements (VSS 2015); the current study extends this result to supra-second judgements, to examine the postulated dissociation between sub- and supra-second timing mechanisms. 141 undergraduate subjects completed the OLIFE schizotypal personality questionnaire prior to performing a modified temporal-bisection task. Subjects responded to two identical instantiations of a 4deg grating, presented 4deg above fixation for 3 secs 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. Subjects were then asked to indicate their 'most accurate estimate' of the two intervals. The stimuli were static and blocked into four repeats of 50 stimulus pairs. The significant order-effect seen in the sub-second data disappeared; this was at the expense of accuracy, as the mid-point was consistently underestimated. Precision in the response was increased as a proportion of total duration, reducing the variance below that predicted by Weber's law. This result is consistent with a breakdown of the scalar properties of time perception in the early supra-second range. All subjects showed good insight into their own performance, though that insight did not necessarily correlate with the veridical bisection point; they were consistently and confidently wrong. The significant correlations with schizotypy seen in the sub-second data were not replicated in the current study. These data support a partial dissociation of timing mechanisms, but also suggest that not only is perception the critical mitigator of confidence in time, but that individuals effectively compensate for differences in perception at the level of metacognition in early supra-second time.
Meeting abstract presented at VSS 2017