Boehler Carsten N, Schevernels Hanne, Hopf Jens-Max, Stoppel Christian M, Krebs Ruth M
Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, 9000, Ghent, Belgium,
Cogn Affect Behav Neurosci. 2014 Jun;14(2):593-609. doi: 10.3758/s13415-014-0251-5.
Response inhibition is an important cognitive-control function that allows for already-initiated or habitual behavioral responses to be promptly withheld when needed. A typical paradigm to study this function is the stop-signal task. From this task, the stop-signal response time (SSRT) can be derived, which indexes how rapidly an already-initiated response can be canceled. Typically, SSRTs range around 200 ms, identifying response inhibition as a particularly rapid cognitive-control process. Even so, it has recently been shown that SSRTs can be further accelerated if successful response inhibition is rewarded. Since this earlier study effectively ruled out differential preparatory (proactive) control adjustments, the reward benefits likely relied on boosted reactive control. Yet, given how rapidly such control processes would need to be enhanced, alternative explanations circumventing reactive control are important to consider. We addressed this question with an fMRI study by gauging the overlap of the brain networks associated with reward-related and response-inhibition-related processes in a reward-modulated stop-signal task. In line with the view that reactive control can indeed be boosted swiftly by reward availability, we found that the activity in key brain areas related to response inhibition was enhanced for reward-related stop trials. Furthermore, we observed that this beneficial reward effect was triggered by enhanced connectivity between task-unspecific (reward-related) and task-specific (inhibition-related) areas in the medial prefrontal cortex (mPFC). The present data hence suggest that reward information can be translated very rapidly into behavioral benefits (here, within ~200 ms) through enhanced reactive control, underscoring the immediate responsiveness of such control processes to reward availability in general.
反应抑制是一种重要的认知控制功能，它能使已经启动的或习惯性的行为反应在需要时迅速被抑制。研究这一功能的典型范式是停止信号任务。从这个任务中，可以得出停止信号反应时间（SSRT），它反映了已经启动的反应能够被取消的速度。通常，SSRTs在200毫秒左右，这表明反应抑制是一个特别快速的认知控制过程。即便如此，最近的研究表明，如果成功的反应抑制得到奖励，SSRTs可以进一步加快。由于早期的这项研究有效地排除了不同的准备性（主动性）控制调整，奖励带来的益处可能依赖于增强的反应性控制。然而，考虑到这种控制过程需要如此迅速地增强，规避反应性控制的其他解释也很重要。我们通过一项功能磁共振成像（fMRI）研究来解决这个问题，该研究测量了奖励调制停止信号任务中与奖励相关和反应抑制相关过程的脑网络重叠情况。与奖励可用性确实能迅速增强反应性控制的观点一致，我们发现与反应抑制相关的关键脑区在与奖励相关的停止试验中的活动增强了。此外，我们观察到这种有益的奖励效应是由内侧前额叶皮层（mPFC）中任务非特异性（奖励相关）和任务特异性（抑制相关）区域之间增强的连通性触发的。因此，目前的数据表明，奖励信息可以通过增强反应性控制非常迅速地转化为行为益处（在此处，约200毫秒内），这突出了这种控制过程一般对奖励可用性的即时反应性。
