Timing, Storage, and Comparison of Stimulus Duration Engage Discrete Anatomical Components of a Perceptual Timing Network
Timing, Storage, and Comparison of Stimulus Duration Engage Discrete Anatomical Components of a Perceptual Timing Network
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DOI：
10.1162/jocn.2008.20153
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发表时间：
2008-12-01
影响因子：
3.2
通讯作者：
Vidal, Franck
中科院分区：
文献类型：
--
作者：
Coull, Jennifer T.;Nazarian, Bruno;Vidal, Franck
时间辨别范式要求受试者将探测刺激的持续时间与先前存储在工作或长期记忆中的样本的持续时间进行比较，从而提供独立于运动反应的计时指数。然而，估计过程本身包含几个组成部分的认知过程，包括计时、存储、检索和持续时间比较。之前的成像研究试图通过简单地测量早期和晚期扫描时期的大脑活动来理清这些成分。我们的目标是通过使用快速事件相关功能磁共振成像来时间锁定对样本和探针刺激本身呈现的血流动力学响应，从而提高这种方法的时间分辨率和精度。与在难度、持续注意力和运动准备要求方面相匹配的控制（颜色估计）任务相比，我们发现左侧壳核的选择性激活用于将刺激持续时间存储（“编码”）到工作记忆（WM）中。此外，壳核活动的增加与计时性能的增强有关，这表明壳核活动的水平可能会调节时间编码的深度。 WM 中的刺激持续时间选择性地激活右颞上回。最后，辅助运动区在任务的采样和探测阶段同样活跃，这表明在计时当前正在及时展开的刺激的持续时间方面发挥着重要作用。
The temporal discrimination paradigm requires subjects to compare the duration of a probe stimulus to that of a sample previously stored in working or long-term memory, thus providing an index of timing that is independent of a motor response. However, the estimation process itself comprises several component cognitive processes, including timing, storage, retrieval, and comparison of durations. Previous imaging studies have attempted to disentangle these components by simply measuring brain activity during early versus late scanning epochs. We aim to improve the temporal resolution and precision of this approach by using rapid event-related functional magnetic resonance imaging to time-lock the hemodynamic response to presentation of the sample and probe stimuli themselves. Compared to a control (color-estimation) task, which was matched in terms of difficulty, sustained attention, and motor preparation requirements, we found selective activation of the left putamen for the storage ("encoding'') of stimulus duration into working memory (WM). Moreover, increased putamen activity was linked to enhanced timing performance, suggesting that the level of putamen activity may modulate the depth of temporal encoding. Retrieval and comparison of stimulus duration in WM selectively activated the right superior temporal gyrus. Finally, the supplementary motor area was equally active during both sample and probe stages of the task, suggesting a fundamental role in timing the duration of a stimulus that is currently unfolding in time.