Automatic Temporal Expectancy: A High-Density Event-Related Potential Study
Automatic Temporal Expectancy: A High-Density Event-Related Potential Study
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DOI：
10.1371/journal.pone.0062896
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发表时间：
2013-05-01
期刊：
影响因子：
3.7
通讯作者：
Bisiacchi, Patrizia Silvia
中科院分区：
文献类型：
--
作者：
Mento, Giovanni;Tarantino, Vincenza;Bisiacchi, Patrizia Silvia
我们如何计算时间还没有完全弄清楚。问题包括自动大脑机制是否参与时间规则的环境结构以预测事件，以及这是否可以与任务相关的过程分离，包括反应准备、选择和执行。为了研究这些问题，在高密度事件相关电位记录过程中，研究人员专门设计了一个被动的时间古怪任务，该任务既不需要基于时间的运动反应，也不需要明确的决定。参与者被呈现给一对视听刺激(S1和S2)，其中散布着根据奇怪的概率分布操纵的刺激间间隔(ISI)。在标准条件下(70%的试验)，ISI持续1500毫秒，而在两种不同的条件下(各15%)，ISI持续2500毫秒和3000毫秒。对标准ISI的被动过度展示驱使参与者自动和渐进地创建对S2开始的内隐时间预期，这反映在或有负变化反应的时间进程中，该时间进程总是对应于S2最大期望点达到峰值，然后在极性上向基线反转。对S1和ISI相关的ERP活动的脑来源分析显示，感觉皮层区域和辅助运动区(SMA)分别被激活。特别是，由于SMA的时间进程与标准的ISI同步，我们认为该区域是颞叶CNV的主要皮质生成器，反映了支撑时间预期的自动的、动作无关的机制。
How we compute time is not fully understood. Questions include whether an automatic brain mechanism is engaged in temporally regular environmental structure in order to anticipate events, and whether this can be dissociated from task-related processes, including response preparation, selection and execution. To investigate these issues, a passive temporal oddball task requiring neither time-based motor response nor explicit decision was specifically designed and delivered to participants during high-density, event-related potentials recording. Participants were presented with pairs of audiovisual stimuli (S1 and S2) interspersed with an Inter-Stimulus Interval (ISI) that was manipulated according to an oddball probabilistic distribution. In the standard condition (70% of trials), the ISI lasted 1,500 ms, while in the two alternative, deviant conditions (15% each), it lasted 2,500 and 3,000 ms. The passive over-exposition to the standard ISI drove participants to automatically and progressively create an implicit temporal expectation of S2 onset, reflected by the time course of the Contingent Negative Variation response, which always peaked in correspondence to the point of S2 maximum expectation and afterwards inverted in polarity towards the baseline. Brain source analysis of S1-and ISI-related ERP activity revealed activation of sensorial cortical areas and the supplementary motor area (SMA), respectively. In particular, since the SMA time course synchronised with standard ISI, we suggest that this area is the major cortical generator of the temporal CNV reflecting an automatic, action-independent mechanism underlying temporal expectancy.