Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, MA, USA.
Aristotle University of Thessaloniki, School of Philosophy, Department of Psychology, Thessaloniki, Greece.
Sci Rep. 2018 Jul 3;8(1):10043. doi: 10.1038/s41598-018-28258-4.
The ability to discriminate temporal intervals in the milliseconds-to-seconds range has been accounted for by proposing that duration is encoded in the dynamic change of a neuronal network state. A critical limitation of such networks is that their activity cannot immediately return to the initial state, a restriction that could hinder the processing of intervals presented in rapid succession. Empirical evidence in the literature consistently shows impaired duration discrimination performance for 100 ms intervals demarked by short auditory stimuli immediately preceded by a similar interval. Here we tested whether a similar interference is present with longer intervals (300 ms) demarked either by auditory or by visual stimuli. Our results show that while temporal estimates of auditory stimuli in this range are not affected by the interval between them, duration discrimination with this duration is significantly impaired with visual intervals presented in rapid succession. The difference in performance between modalities is overall consistent with state-dependent temporal computations, as it suggests that the limits due to slow neuronal dynamics greatly depends on the sensory modality with which the intervals are demarked, in line with the idea of intrinsic, modality-specific neural mechanisms for interval timing.
毫秒到秒范围内的时间间隔辨别能力可以通过提出神经元网络状态的动态变化来编码来解释。这种网络的一个关键限制是它们的活动不能立即回到初始状态，这种限制可能会阻碍快速连续呈现的间隔的处理。文献中的实证证据一致表明，对于由短听觉刺激标记的 100 毫秒间隔，以及紧随其后的类似间隔，持续时间辨别性能受损。在这里，我们测试了在更长的间隔（300 毫秒）中是否存在类似的干扰，这些间隔是由听觉或视觉刺激标记的。我们的结果表明，虽然在这个范围内听觉刺激的时间估计不受它们之间间隔的影响，但随着快速连续呈现视觉间隔，这种持续时间的持续时间辨别能力显著受损。不同模态之间的性能差异总体上与基于状态的时间计算一致，因为这表明由于神经元动力学较慢而导致的限制在很大程度上取决于用哪种感觉模态来标记间隔，这与间隔计时的内在、模态特异性神经机制的想法一致。
