Li C-S R, Yan P, Chao H H-A, Sinha R, Paliwal P, Constable R T, Zhang S, Lee T-W
Department of Psychiatry, Connecticut Mental Health Center, Yale University School of Medicine, New Haven, CT 06519, USA.
Neuroscience. 2008 Sep 9;155(4):1142-51. doi: 10.1016/j.neuroscience.2008.06.062. Epub 2008 Jul 8.
The ability to detect errors and adjust behavior accordingly is essential for maneuvering in an uncertain environment. Errors are particularly prone to occur when multiple, conflicting responses are registered in a situation that requires flexible behavioral outputs. Previous studies have provided evidence indicating the importance of the medial cortical brain regions including the cingulate cortex in processing conflicting information. However, conflicting situations can be successfully resolved, or lead to errors, prompting a behavioral change in the observers. In particular, how does the brain use error signals specifically to adjust behavior on the fly? Here we employ a stop signal task (SST) to elicit errors approximately half of the time in high-conflict trials despite constant behavioral adjustment of the observers. Using functional magnetic resonance imaging, we show greater and, sequentially, less activation in the medial cortical regions when observers made an error, compared with when they successfully resolved high-conflict responses. Errors also evoked greater activity in the cuneus, retrosplenial cortex, insula, and subcortical structures including the thalamus and the region of the epithalamus (the habenula). We further showed that the error-related medial cortical activities are not correlated with post-error behavioral adjustment, as indexed by post-error slowing (PES) in go trial reaction time. These results delineate an error-specific pattern of brain activation during the SST. The results also suggest that the relationship between error-related activity and post-error behavioral adjustment may be more complicated than has been conceptualized by the conflict monitoring hypothesis.
在不确定的环境中灵活行动，检测错误并据此调整行为的能力至关重要。当在需要灵活行为输出的情境中记录到多种相互冲突的反应时，尤其容易出现错误。先前的研究提供了证据，表明包括扣带回皮质在内的内侧皮质脑区在处理冲突信息方面的重要性。然而，冲突情境可以成功解决，也可能导致错误，从而促使观察者的行为发生改变。特别是，大脑如何具体利用错误信号即时调整行为呢？在这里，我们采用停止信号任务（SST），尽管观察者不断进行行为调整，但在高冲突试验中仍有大约一半的时间会引发错误。利用功能磁共振成像，我们发现与成功解决高冲突反应相比，观察者犯错时内侧皮质区域的激活先增强后减弱。错误还在楔叶、压后皮质、脑岛以及包括丘脑和上丘脑区域（缰核）在内的皮质下结构中引发了更强的活动。我们进一步表明，错误相关的内侧皮质活动与错误后行为调整不相关，错误后行为调整以继续试验反应时中的错误后减缓（PES）为指标。这些结果描绘了SST期间特定于错误的大脑激活模式。结果还表明，错误相关活动与错误后行为调整之间的关系可能比冲突监测假说所设想的更为复杂。
