Task-switching is one of the most popular paradigms to investigate cognitive control. The main finding of interest is the switch cost: RTs in switch trials are longer than RTs in repetition trials. Despite the massive amount of research in these topics, little is known about the underlying temporal dynamics of the cortical regions involved in these phenomena.

Here we used high density EEG to unveil the spatiotemporal neural dynamics associated with both the switch cost and to its modulation over time (time-on-task effect), as two markers of cognitive control reflecting effortful and procedural mechanisms, respectively. We found that, as a function of task practice, the switch cost decreased and both the switch-positivity and the switch-negativity event-related responses increased, although the latter showed a larger modulatory effect. At a source level, this effect was revealed by a progressively higher activation of the left middle and superior frontal gyrus.

任务切换是研究认知控制的最流行范例之一。感兴趣的主要发现是转换成本：转换试验中的RT比重复试验中的RT长。尽管在这些主题上进行了大量研究，但对于涉及这些现象的皮质区域的潜在时间动态知之甚少。

在这里，我们使用高密度脑电图揭示了时空神经动力学，它与切换成本及其随时间的调制（工作时间效应）相关，作为认知控制的两个标志，分别反映了努力的和程序的机制。我们发现，作为任务实践的函数，开关成本降低，并且开关阳性和开关阴性事件相关的响应都增加，尽管后者显示出更大的调节作用。从源头上看，这种作用通过左中上额额回和上额额回的逐渐增加的激活来揭示。