Department of Psychology, University of Groningen, Groningen, 9712 TS, The Netherlands
Department of Psychology, University of Groningen, Groningen, 9712 TS, The Netherlands.
J Neurosci. 2021 May 19;41(20):4514-4523. doi: 10.1523/JNEUROSCI.0628-20.2021. Epub 2021 Apr 8.
Our subjective perception of time is optimized to temporal regularities in the environment. This is illustrated by the central tendency effect: When estimating a range of intervals, short intervals are overestimated, whereas long intervals are underestimated to reduce the overall estimation error. Most models of interval timing ascribe this effect to the weighting of the current interval with previous memory traces after the interval has been perceived. Alternatively, the perception of the duration could already be flexibly tuned to its temporal context. We investigated this hypothesis using an interval reproduction task in which human participants (both sexes) reproduced a shorter and longer interval range. As expected, reproductions were biased toward the subjective mean of each presented range. EEG analyses showed that temporal context indeed affected neural dynamics during the perception phase. Specifically, longer previous durations decreased contingent negative variation and P2 amplitude and increased beta power. In addition, multivariate pattern analysis showed that it is possible to decode context from the transient EEG signal quickly after both onset and offset of the perception phase. Together, these results suggest that temporal context creates dynamic expectations which actively affect the perception of duration. The subjective sense of duration does not arise in isolation, but is informed by previous experiences. This is demonstrated by abundant evidence showing that the production of duration estimates is biased toward previously experienced time intervals. However, it is yet unknown whether this temporal context actively affects perception or only asserts its influence in later, postperceptual stages as proposed by most current formal models of this task. Using an interval reproduction task, we show that EEG signatures flexibly adapt to the temporal context during perceptual encoding. Furthermore, interval history can be decoded from the transient EEG signal even when the current duration was identical. Thus, our results demonstrate that context actively influences perception.
我们对时间的主观感知是优化的，以适应环境中的时间规律。这一现象体现在中央趋势效应中：在估计一系列时间间隔时，短时间间隔会被高估，而长时间间隔会被低估，以减少总体估计误差。大多数时间间隔计时模型将这种效应归因于在感知到间隔后，对当前间隔进行加权，同时考虑先前的记忆痕迹。或者，对持续时间的感知可以灵活地根据其时间上下文进行调整。我们使用间隔再现任务来研究这一假设，在该任务中，人类参与者（男女都有）再现了较短和较长的间隔范围。正如预期的那样，再现会偏向于呈现的每个范围内的主观平均值。脑电图分析表明，时间上下文确实会影响感知阶段的神经动力学。具体来说，较长的先前持续时间会降低伴随负变和 P2 振幅，并增加β功率。此外，多元模式分析表明，在感知阶段的开始和结束后，从瞬态 EEG 信号中解码上下文是可能的。总之，这些结果表明，时间上下文会产生动态的预期，这些预期会主动影响对持续时间的感知。持续时间的主观感觉不是孤立产生的，而是受到先前经验的影响。这一点有大量证据表明，在产生持续时间估计时，会偏向于先前经历过的时间间隔。然而，目前关于这项任务的大多数正式模型都认为，时间上下文是否主动影响感知，或者只是在感知后阶段施加其影响，尚不清楚。我们使用间隔再现任务表明，在感知编码过程中，脑电图特征可以灵活地适应时间上下文。此外，即使当前持续时间相同，也可以从瞬态 EEG 信号中解码间隔历史。因此，我们的结果表明，上下文会主动影响感知。
