Egner Tobias, Hirsch Joy
Functional MRI Research Center, Columbia University, New York, NY 10032, USA.
Neuroimage. 2005 Jan 15;24(2):539-47. doi: 10.1016/j.neuroimage.2004.09.007.
It is well known that performance on a given trial of a cognitive task is affected by the nature of previous trials. For example, conflict effects on interference tasks, such as the Stroop task, are reduced subsequent to high-conflict trials relative to low-conflict trials. This interaction effect between previous and current trial types is called "conflict adaptation" and thought to be due to processing adjustments in cognitive control. The current study aimed to identify the neural substrates of cognitive control during conflict adaptation by isolating neural correlates of reduced conflict from those of increased cognitive control. We expected cognitive control to be implemented by prefrontal cortex through context-specific modulation of posterior regions involved in sensory and motor aspects of task performance. We collected event-related fMRI data on a color-word naming Stroop task and found distinct fronto-parietal networks of current trial conflict detection and conflict adaptation through cognitive control. Conflict adaptation was associated with increased activity in left middle frontal gyrus (GFm) and superior frontal gyrus (GFs), consistent with increased cognitive control, and with decreased activity in bilateral prefrontal and parietal cortices, consistent with reduced response conflict. Psychophysiological interaction analysis (PPI) revealed that cognitive control activation in GFs and GFm was accompanied by increased functional integration with bilateral inferior frontal, right temporal and parietal areas, and the anterior cerebellum. These data suggest that cognitive control is implemented by medial and lateral prefrontal cortices that bias processes in regions that have been implicated in high-level perceptual and motor processes.
众所周知，在认知任务的给定试验中，表现会受到先前试验性质的影响。例如，在诸如斯特鲁普任务等干扰任务上的冲突效应，相对于低冲突试验，在高冲突试验之后会降低。先前试验类型与当前试验类型之间的这种交互效应被称为“冲突适应”，并被认为是由于认知控制中的加工调整所致。当前的研究旨在通过将冲突减少的神经关联与认知控制增强的神经关联区分开来，确定冲突适应过程中认知控制的神经基础。我们预期认知控制是由前额叶皮层通过对参与任务表现的感觉和运动方面的后部区域进行特定情境的调节来实现的。我们收集了关于颜色-单词命名斯特鲁普任务的事件相关功能磁共振成像数据，并通过认知控制发现了当前试验冲突检测和冲突适应的不同额顶叶网络。冲突适应与左侧额中回（GFm）和额上回（GFs）的活动增加有关，这与认知控制增强一致，同时与双侧前额叶和顶叶皮质的活动减少有关，这与反应冲突减少一致。心理生理交互分析（PPI）显示，GFs和GFm中的认知控制激活伴随着与双侧额下回、右侧颞叶和顶叶区域以及前小脑的功能整合增加。这些数据表明，认知控制是由内侧和外侧前额叶皮层实现的，它们对涉及高级感知和运动过程的区域中的加工过程产生偏向作用。
