BACKGROUND: The ability to estimate the passage of time is of fundamental importance for
perceptual and cognitive processes. One experience of time is the
perception of duration, which is not isomorphic to physical duration and can be distorted by a number of factors. Yet, the critical features generating these
perceptual shifts in subjective duration are not understood. METHODOLOGY/FINDINGS: We used prospective duration judgments within and across
sensory modalities to examine the effect of stimulus
predictability and feature change on the
perception of duration. First, we found robust distortions of
perceived duration in auditory,
visual and auditory-visual presentations despite the
predictability of the feature changes in the stimuli. For example, a looming
disc embedded in a series of steady
discs led to time dilation, whereas a steady
disc embedded in a series of looming
discs led to time compression. Second, we addressed whether
visual (auditory) inputs could alter the
perception of duration of auditory (
visual) inputs. When participants were presented with incongruent audio-visual stimuli, the
perceived duration of auditory events could be shortened or lengthened by the presence of conflicting
visual information; however, the
perceived duration of
visual events was seldom distorted by the presence of auditory information and was never
perceived shorter than their actual durations. CONCLUSIONS/SIGNIFICANCE: These results support the existence of multisensory interactions in the
perception of duration and, importantly, suggest that vision can modify auditory
temporal perception in a pure timing task. Insofar as distortions in subjective duration can neither be accounted for by the
unpredictability of an auditory,
visual or auditory-visual event, we propose that it is the intrinsic features of the stimulus that critically affect subjective time distortions.
