University of California, Los Angeles, CA 90095, USA.
J Cogn Neurosci. 2011 Nov;23(11):3388-99. doi: 10.1162/jocn_a_00031. Epub 2011 Mar 31.
The right inferior frontal gyrus (rIFG) has been hypothesized to mediate response inhibition. Typically response inhibition is signaled by an external stop cue, which provides a top-down signal to initiate the process. However, recent behavioral findings suggest that response inhibition can also be triggered automatically by bottom-up processes. In the present study, we evaluated whether rIFG activity would also be observed during automatic inhibition, in which no stop cue was presented and no motor inhibition was actually required. We measured rIFG activation in response to stimuli that were previously associated with stop signals but which required a response on the current trial (reversal trials). The results revealed an increase in rIFG (pars triangularis) activity, suggesting that it can be activated by associations between stimuli and stopping. Moreover, its role in inhibition tasks is not contingent on the presence of an external stop cue. We conclude that rIFG involvement in stopping is consistent with a role in reprogramming of action plans, which may comprise inhibition, and its activity can be triggered through automatic, bottom-up processing.
右侧额下回（rIFG）被假设介导反应抑制。通常情况下，反应抑制由外部停止线索信号发出，这提供了一个自上而下的信号来启动该过程。然而，最近的行为研究结果表明，反应抑制也可以通过自下而上的过程自动触发。在本研究中，我们评估了在没有呈现停止线索且实际上不需要运动抑制的情况下，rIFG 活动是否也会在自动抑制中被观察到。我们测量了 rIFG 在对先前与停止信号相关但当前试验需要反应（反转试验）的刺激的反应中的激活。结果显示 rIFG（三角部）的活性增加，表明它可以通过刺激与停止之间的关联被激活。此外，它在抑制任务中的作用不依赖于外部停止线索的存在。我们得出结论，rIFG 参与停止与重新编程动作计划的作用一致，这可能包括抑制，并且它的活动可以通过自动的、自下而上的处理来触发。
