Rubia Katya, Smith Anna B, Brammer Michael J, Taylor Eric
Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK.
Neuroimage. 2003 Sep;20(1):351-8. doi: 10.1016/s1053-8119(03)00275-1.
Inhibitory control and error detection are among the highest evolved human self-monitoring functions. Attempts in functional neuroimaging to effectively isolate inhibitory motor control from other cognitive functions have met with limited success. Different brain regions in inferior, mesial, and dorsolateral prefrontal cortices and parietal and temporal lobes have been related to inhibitory control in go/no-go and stop tasks. The widespread activation reflects the fact that the designs used so far have comeasured additional noninhibitory cognitive functions such as selective attention, response competition, decision making, target detection, and inhibition failure. Here we use rapid, mixed trial, event-related functional magnetic resonance imaging to correlate brain activation with an extremely difficult situation of inhibitory control in a challenging stop task that controls for noninhibitory functions. The difficulty of the stop task, requiring withholding of a triggered motor response, was assured by an algorithm that adjusted the task individually so that each subject only succeeded on half of all stop trials, failing on the other half. This design allowed to elegantly separate brain activation related to successful motor response inhibition and to inhibition failure or error detection. Brain activation correlating with successful inhibitory control in 20 healthy volunteers could be isolated in right inferior prefrontal cortex. Failure to inhibit was associated with activation in mesial frontopolar and bilateral inferior parietal cortices, presumably reflecting an attention network for error detection.
抑制控制和错误检测是人类进化程度最高的自我监测功能之一。在功能神经成像中，试图有效区分抑制性运动控制与其他认知功能的尝试取得的成功有限。额下回、内侧和背外侧前额叶皮质以及顶叶和颞叶的不同脑区已被证实与停止信号任务和去/不去任务中的抑制控制有关。广泛的激活反映了这样一个事实，即到目前为止所采用的设计还同时测量了额外的非抑制性认知功能，如选择性注意、反应竞争、决策、目标检测和抑制失败。在这里，我们使用快速、混合试验、事件相关功能磁共振成像，将大脑激活与一个具有挑战性的停止信号任务中的抑制控制极端困难情况相关联，该任务可控制非抑制性功能。停止信号任务的难度在于需要抑制触发的运动反应，这通过一种算法来确保，该算法会根据个体情况调整任务，使每个受试者在所有停止信号试验中只有一半成功，另一半失败。这种设计能够巧妙地分离与成功运动反应抑制以及抑制失败或错误检测相关的大脑激活。在20名健康志愿者中，与成功抑制控制相关的大脑激活可在右侧额下回中分离出来。抑制失败与内侧额极和双侧顶下皮质的激活有关，这可能反映了一个用于错误检测的注意网络。
