Crone Eveline A, Wendelken Carter, Donohue Sarah E, Bunge Silvia A
Center for Mind and Brain, University of California, Davis, USA.
Cereb Cortex. 2006 Apr;16(4):475-86. doi: 10.1093/cercor/bhi127. Epub 2005 Jul 6.
The ability to retrieve and flexibly switch between task rules is seen as an important component of cognitive control. It is often assumed that lateral prefrontal cortex (latPFC) is important for switching between rules. However, activation associated with rule-switching is less reliably observed in latPFC than in medial PFC (specifically, pre-supplementary motor area). In this study, we tested the hypothesis that medial PFC is important for reconfiguration of task sets, whereas latPFC is important for retrieving, maintaining and implementing relevant rules (i.e. rule representation). Twenty young adults participated in a functional magnetic resonance imaging study in which they determined the correct response to a target stimulus on the basis of an instructional cue. For bivalent targets, the appropriate response depended on the currently relevant rule. In contrast, univalent targets were always associated with the same response. Brain regions of interest were characterized according to their responsiveness to bivalent and univalent targets, on both rule-switch and rule-repetition trials. The data support the hypothesis that rule representation and task-set reconfiguration are separable cognitive processes, associated with dissociable neural activation in latPFC and medial PFC, respectively. Activation profiles of posterior parietal cortex, basal ganglia and rostrolateral PFC are also examined and discussed.
在任务规则之间进行检索和灵活切换的能力被视为认知控制的一个重要组成部分。人们通常认为外侧前额叶皮层（latPFC）对于规则切换很重要。然而，与规则切换相关的激活在latPFC中不如在内侧前额叶皮层（具体来说，是前辅助运动区）中观察得可靠。在本研究中，我们检验了以下假设：内侧前额叶皮层对于任务集的重新配置很重要，而latPFC对于检索、维持和执行相关规则（即规则表征）很重要。20名年轻成年人参与了一项功能磁共振成像研究，他们根据指示线索确定对目标刺激的正确反应。对于二价目标，适当的反应取决于当前相关的规则。相比之下，单价目标总是与相同的反应相关联。根据在规则切换和规则重复试验中对二价和单价目标的反应性，对感兴趣的脑区进行了表征。数据支持以下假设：规则表征和任务集重新配置是可分离的认知过程，分别与latPFC和内侧前额叶皮层中可分离的神经激活相关。还对顶叶后皮层、基底神经节和额外侧PFC的激活情况进行了检查和讨论。
