Abstract
The duration of a flickering stimulus is perceived as longer than that of a stable stimulus. This kind of phenomenon, also known as time distortion, has been widely used in studies of time perception. Although many hypotheses about time encoding have been reported, including a spatially specific clock system and the general magnitude system, recent electrophysiological studies have shown that interval information can be encoded by neural oscillations. In this study, we investigated whether neural oscillations can explain time dilation induced by flickering visual stimuli. During the experiments, subjects were asked to reproduce the duration of the target stimulus (450, 650, or 850 ms) while the temporal frequencies of the target or distractors were modulated. In experiment 1 (N = 9), the distractors appeared before the target onset and disappeared after the target offset. The reproduced target duration was longer when either the target or distractor flickered compared to when either one was stable. In addition, a flickering distractor ipsilateral to the target induced longer dilation than a flickering distractor contralateral to the target. Flickering distractors caused longer time dilations than flickering targets. In experiment 2 (N = 9), similar durations were used for both the distractors and the target. Although flickering distractors still induced time dilation, dilation induced by flickering distractors was shorter than that induced by the flickering target. There are three important findings from this study. First, flickering task-irrelevant distractors distort the perceived duration of target stimuli. Second, the amount of dilation depends on the distance between cortical areas, which correspond to stimulus locations. Finally, longer-duration flickering distractors caused longer time dilation. These findings support the hypothesis that time information is encoded by neural oscillations.
Meeting abstract presented at VSS 2016