Neuroimaging Laboratory, Santa Lucia Foundation, via Ardeatina, 306, Rome, Italy.
Neuroimage. 2011 Aug 1;57(3):1251-63. doi: 10.1016/j.neuroimage.2011.05.014. Epub 2011 May 12.
Clock-counter models, the most influential cognitive models of temporal computation, have been successful in explaining a large set of behavioral data. However, it remains unclear whether the component operations postulated in these models correspond to any specific biological mechanism. Using stimuli in different sensory modalities and manipulating physical properties known to bias the 'subjective' perception of time (speed for vision and pitch for audition), the present study aimed to highlight brain areas where activity correlates with the 'subjective' perception of time: a time accumulator according to clock-counter models. Using functional MRI we found that during the encoding of a temporal interval in the millisecond range (600 and 1000 ms), the hemodynamic response of a few brain regions correlated with the interval reproduction performance. For the visual modality, the activity of the putamen, the mid-insula and the mid-temporal cortex reflected the subjective interval duration, which was biased according to the different speeds of the visual stimuli. This effect was found only when subjects encoded the stimulus duration and was specific for the visual modality, where a significant overestimation of time with increasing speed was observed. These results demonstrate a definite relation between 'subjective time' and brain activity, supporting the hypothesis of a physiological correlate of time 'accumulation'.
钟摆计数器模型是最具影响力的时间计算认知模型之一，它成功地解释了大量行为数据。然而，这些模型中假定的组成操作是否对应于任何特定的生物机制仍不清楚。本研究使用不同感觉模态的刺激，并操纵已知会影响“主观”时间感知的物理属性（视觉的速度和听觉的音高），旨在突出与“主观”时间感知相关的大脑区域：根据钟摆计数器模型的时间累加器。使用功能磁共振成像，我们发现，在毫秒范围内（600 到 1000 毫秒）的时间间隔编码过程中，几个大脑区域的血液动力学反应与间隔再现性能相关。对于视觉模态，壳核、中脑岛和中颞皮质的活动反映了主观的间隔持续时间，这受到视觉刺激不同速度的影响。这种效应仅在受试者编码刺激持续时间时才出现，并且是视觉模态特有的，在视觉模态中观察到随着速度的增加而对时间的显著高估。这些结果表明“主观时间”和大脑活动之间存在明确的关系，支持时间“累加”的生理相关假设。
