Post-interval potentials in temporal judgements

Research suggests that post-stimulus positive deflections could be associated with timing. We compared offset-locked potentials N1, P2, N1P2, and late positive component (LPC) in temporal generalization and temporal bisection-with visual probe intervals. In both tasks, the LPC amplitude decreased with the duration of the current probe interval. A larger LPC was found after shorter intervals, whereas other ERP amplitudes did not change between tasks or across durations. We also found that the LPC for different responses indicates subjective time. We discussed our findings in relation to theories of human timing.

The contents of visual working memory delay the perceived offset of matching visual stimuli

Previous research suggests that the perception of stimulus onset can be accelerated by a match between the contents of visual working memory and the stimulus presented alone in the peripheral visual field. This onset acceleration effect might contribute to previously reported effects of working memory on perceived stimulus duration. However, it remains possible that the contents of visual working memory may also modulate the offset perception of matching visual stimuli, thereby contributing to the modulation of duration perception by working memory. The present study directly tested this possibility by using a simple reaction time task to assess the effect of visual working memory on perceived stimulus offset. Participants were asked to maintain a sample stimulus in working memory and subsequently had to respond to the offset of a single visual target. Across three experiments, we showed that the offset response was reliably slower when the target matched the sample held in visual working memory, as compared with when the target did not. This effect was not likely attributed to the mechanism of repetition priming from the presentation of the sample, because we failed to observe a priming effect either when the sample was only passively viewed without working memory demands or when the sample was initially encoded into memory but did not need to be actively maintained in mind by the time the offset target appeared. The findings provide direct evidence indicating that active maintenance of information in visual working memory delays the perceived offset of matching visual stimuli.