Subjective Duration Distortions Mirror Neural Repetition Suppression

Abstract

BackgroundSubjective duration is strongly influenced by repetition and novelty, such that an oddball stimulus in a stream of repeated stimuli appears to last longer in duration in comparison. We hypothesize that this duration illusion, called the temporal oddball effect, is a result of the difference in expectation between the oddball and the repeated stimuli. Specifically, we conjecture that the repeated stimuli contract in duration as a result of increased predictability; these duration contractions, we suggest, result from decreased neural response amplitude with repetition, known as repetition suppression.Methodology/Principal FindingsParticipants viewed trials consisting of lines presented at a particular orientation (standard stimuli) followed by a line presented at a different orientation (oddball stimulus). We found that the size of the oddball effect correlates with the number of repetitions of the standard stimulus as well as the amount of deviance from the oddball stimulus; both of these results are consistent with a repetition suppression hypothesis. Further, we find that the temporal oddball effect is sensitive to experimental context – that is, the size of the oddball effect for a particular experimental trial is influenced by the range of duration distortions seen in preceding trials.Conclusions/SignificanceOur data suggest that the repetition-related duration contractions causing the oddball effect are a result of neural repetition suppression. More generally, subjective duration may reflect the prediction error associated with a stimulus and, consequently, the efficiency of encoding that stimulus. Additionally, we emphasize that experimental context effects need to be taken into consideration when designing duration-related tasks.

Subjective Duration as a Signature of Coding Efficiency: Emerging Links Among Stimulus Repetition, Predictive Coding, and Cortical GABA Levels

“…The oddball effect increases with increasing presentations of the standard, consistent with progressively stronger RS of increasingly predictable items (Kim & McAuley, 2013;Pariyadath & Eagleman, 2012). In addition, for oddball tasks in which a deviation in line orientation has to be detected, the oddball effect is positively related to the discrepancy between the angle of the repeated and novel items, consistent with the idea that the effect is driven by the size of the mismatch between observed and predicted sensory input (Pariyadath and Eagleman, 2012;Schindel et al, 2011; but see Kim & McAuley, 2013).…”

Attentional entrainment and perceived event duration

“…One alternative explanation of the oddball effect that has been proposed is that it is an indirect consequence of reduced neural activity in response to the repeated standard stimulus [24,27,30]. According to the repetition suppression/predictive coding view, temporal expansion of an oddball event in an otherwise identical stream of events occurs because the repeated or more generally predictable standard stimulus that precedes the oddball stimulus produces habituation, rather than because the oddball stimulus produces attentional capture.…”

“…That is, the longer the interval preceding the oddball, the more participants were able to predict that the oddball was going to occur (i.e. prepare for the oddball to occur), akin to a variable foreperiod effect [28][29][30]. To consider this possibility, we conducted a second experiment wherein we kept the short (469 ms), medium (700 ms) and long (931 ms) IOIs preceding the oddball the same, comprising the early, on-time and late conditions in Experiment 1, but varied the tempo of the stimulus sequence so that the relative onset time of the oddball varied.…”

“…Previous studies have shown that the duration of the oddball stimulus tends to be overestimated [13,24], but various factors influence the magnitude of this effect [25][26][27] and not all studies have revealed overestimation [28][29][30]. Tse and co-workers manipulated perceptual features of oddball/ standards and standard duration (ranging from 75 to 2100 ms) in a series of experiments involving an oddball paradigm in which stimuli mostly consisted of simple visual shapes, but also included auditory oddball conditions [13].…”

Effects of pitch distance and likelihood on the perceived duration of deviant auditory events

“…A different theoretical account is that the oddball effect is an indirect consequence of reduced neural activity in response to the repeated standard stimulus (Pariyadath & Eagleman, 2007, 2012Schindel, Rowlands, & Arnold, 2011). On this repetition suppression view, the temporal expansion of the oddball event is a by-product of reduced neural activity to the repeated or more generally predictable stimulus, rather than the result of enhanced attention to the oddball stimulus.…”