Rhythmic brain activity may reflect a functional mechanism that facilitates cortical processing and dynamic interareal interactions and thereby give rise to complex behavior. Using magnetoencephalography (MEG), we investigated rhythmic brain activity in a brain-wide network and their relation to behavior, while human subjects executed a variant of the Simon task, a simple stimulus-response task with well-studied behavioral effects. We hypothesized that the faster reaction times (RT) on stimulus-response congruent versus incongruent trials are associated with oscillatory power changes, reflecting a change in local cortical activation. Additionally, we hypothesized that the faster reaction times for trials following instances with the same stimulus-response contingency (the so-called Gratton effect) is related to contingency-induced changes in the state of the network, as measured by differences in local spectral power and interareal phase coherence. This would be achieved by temporarily upregulating the connectivity strength between behaviorally relevant network nodes. We identified regions-of-interest that differed in local synchrony during the response phase of the Simon task. Within this network, spectral power in none of the nodes in either of the studied frequencies was significantly different in the pre-cue window of the subsequent trial. Nor was there a significant difference in coherence between the task-relevant nodes that could explain the superior behavioral performance after compatible consecutive trials.

中文翻译：

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调查刺激前皮质振荡活动对行为的影响

有节奏的大脑活动可能反映了一种促进皮层处理和动态区域间相互作用的功能机制，从而产生复杂的行为。使用脑磁图 (MEG)，我们研究了全脑网络中的节律性大脑活动及其与行为的关系，而人类受试者则执行了 Simon 任务的变体，这是一项简单的刺激反应任务，对行为影响进行了深入研究。我们假设刺激-反应一致与不一致试验的更快反应时间 (RT) 与振荡功率变化有关，反映了局部皮层激活的变化。此外，我们假设，在具有相同刺激 - 反应偶然性（所谓的格拉顿效应）的实例之后的试验的更快反应时间与网络状态的偶然性引起的变化有关，如通过局部光谱功率和区域间的差异来衡量的相位一致性。这将通过临时上调行为相关网络节点之间的连接强度来实现。我们确定了在 Simon 任务的响应阶段在本地同步方面不同的感兴趣区域。在该网络中，在后续试验的预提示窗口中，任一研究频率中没有一个节点的频谱功率有显着差异。