Fractionating the neural substrate of cognitive control processes
Fractionating the neural substrate of cognitive control processes
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DOI：
10.1073/pnas.222193299
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发表时间：
2002-10-29
影响因子：
11.1
通讯作者：
Berman, KF
中科院分区：
文献类型：
--
作者：
Dreher, JC;Berman, KF
认知控制的心理学和神经生物学理论必须解释认知操作之间灵活的、看似不明显的转变。当受试者在不同的任务之间切换时，他们必须抑制前一项任务，并重新参与另一项任务。对脱离任务的抑制在一段时间内保持活跃，当重新参与同一任务时必须克服。在这里，我们使用了任务切换范式，该范式允许区分两个控制过程：当重新参与之前执行的任务时，克服该任务的抑制；以及在中断一段时间后重新启动一系列任务。在行为上，这些过程反映在以下事实上：(I)切换到最近执行的任务，因此不太可能从抑制中完全恢复，比切换到最近较少执行的任务所需的时间更长，以及(Ii)在中断一段时间后重新参与一系列任务会瞬时增加反应时间。使用事件相关功能磁共振成像，我们发现这两种行为效应伴随着双重分离：与最近执行的任务相比，切换到最近执行的任务时，右侧前额叶皮质更活跃，而当启动一系列任务时，前扣带回皮质被招募。这些结果提供了对人类额叶的功能组织及其在涉及认知控制的不同过程中的作用的见解。
Psychological and neurobiological theories of cognitive control must account for flexible, seemless transitions among cognitive operations. When subjects switch between tasks, they must both inhibit the previous task and re-engage in a different task. Inhibition of the disengaged task remains active for a period of time and has to be overcome when re-engaging in the same task. Here we used a task-switching paradigm that allows distinction of two control processes: overcoming the inhibition of a previously performed task when re-engaging it and restarting a sequence of tasks after a period of interruption. Behaviorally, these processes were reflected in the facts that: (i) switching to a recently performed task, that is thus unlikely to have fully recovered from inhibition, takes longer than switching to a task less recently performed and (ii) re-engaging in a sequence of tasks after a period of interruption transiently increases response time. Using event-related functional MRI, we found that these two behavioral effects were accompanied by a double dissociation: the right lateral prefrontal cortex was more activated when switching to a task recently performed compared to a task less recently performed, while the anterior cingulate cortex was recruited when a sequence of tasks was initiated. These results provide insights into the functional organization of the frontal lobe in humans and its role in distinct processes involved in cognitive control.