Department of Experimental Psychology, Ghent University, Ghent, 9000, Belgium, and Center for Cognitive Neuroscience, Duke University, Durham, North Carolina 27708.
J Neurosci. 2013 Oct 23;33(43):16961-70. doi: 10.1523/JNEUROSCI.1208-13.2013.
Cognitive control requires a fine balance between stability, the protection of an on-going task-set, and flexibility, the ability to update a task-set in line with changing contingencies. It is thought that emotional processing modulates this balance, but results have been equivocal regarding the direction of this modulation. Here, we tested the hypothesis that a crucial determinant of this modulation is whether affective stimuli represent performance-contingent or task-irrelevant signals. Combining functional magnetic resonance imaging with a conflict task-switching paradigm, we contrasted the effects of presenting negative- and positive-valence pictures on the stability/flexibility trade-off in humans, depending on whether picture presentation was contingent on behavioral performance. Both the behavioral and neural expressions of cognitive control were modulated by stimulus valence and performance contingency: in the performance-contingent condition, cognitive flexibility was enhanced following positive pictures, whereas in the nonperformance-contingent condition, positive stimuli promoted cognitive stability. The imaging data showed that, as anticipated, the stability/flexibility trade-off per se was reflected in differential recruitment of dorsolateral frontoparietal and striatal regions. In contrast, the affective modulation of stability/flexibility shifts was mirrored, unexpectedly, by neural responses in ventromedial prefrontal and posterior cingulate cortices, core nodes of the "default mode" network. Our results demonstrate that the affective modulation of cognitive control depends on the performance contingency of the affect-inducing stimuli, and they document medial default mode regions to mediate the flexibility-promoting effects of performance-contingent positive affect, thus extending recent work that recasts these regions as serving a key role in on-task control processes.
认知控制需要在稳定性和灵活性之间取得精细的平衡，前者保护正在进行的任务集，后者使任务集能够根据不断变化的环境进行更新。人们认为情绪处理会调节这种平衡，但关于这种调节的方向，结果一直存在争议。在这里，我们检验了这样一个假设，即这种调节的一个关键决定因素是情感刺激是代表与绩效相关的信号还是与任务无关的信号。我们结合功能磁共振成像和冲突任务转换范式，对比了在人类中呈现负性和正性图片对稳定性/灵活性权衡的影响，这取决于图片呈现是否取决于行为表现。认知控制的行为和神经表达都受到刺激效价和表现关联性的调节：在表现关联性条件下，正性图片增强了认知灵活性，而在非表现关联性条件下，正性刺激促进了认知稳定性。成像数据表明，如预期的那样，稳定性/灵活性权衡本身反映了背外侧额顶叶和纹状体区域的差异招募。相比之下，出乎意料的是，稳定性/灵活性转变的情感调节反映在腹内侧前额叶和后扣带回皮层的神经反应中，这些区域是“默认模式”网络的核心节点。我们的结果表明，认知控制的情感调节取决于引起情感的刺激的表现关联性，并且记录了内侧默认模式区域介导了与表现关联性的正性情感相关的灵活性促进作用，从而扩展了最近的工作，重新定义了这些区域在任务相关控制过程中发挥关键作用。
