Department of Psychology, Michigan State University, East Lansing, 48824, USA.
Cogn Affect Behav Neurosci. 2012 Dec;12(4):629-43. doi: 10.3758/s13415-012-0105-y.
How does switching tasks affect our ability to monitor and adapt our behavior? Largely independent lines of research have examined how individuals monitor their actions and adjust to errors, on the one hand, and how they are able to switch between two or more tasks, on the other. Few studies, however, have explored how these two aspects of cognitive-behavioral flexibility interact. That is, how individuals monitor their actions when task rules are switched remains unknown. The present study sought to address this question by examining the action-monitoring consequences of response switching-a form of task switching that involves switching the response that is associated with a particular stimulus. We recorded event-related brain potentials (ERPs) while participants performed a modified letter flanker task in which the stimulus-response (S-R) mappings were reversed between blocks. Specifically, we examined three ERPs-the N2, the error-related negativity (ERN), and the error positivity (Pe)-that have been closely associated with action monitoring. The findings revealed that S-R reversal blocks were associated with dynamic alterations of action-monitoring brain activity: the N2 and ERN were enhanced, whereas the Pe was reduced. Moreover, participants were less likely to adapt their posterror behavior in S-R reversal blocks. Taken together, these data suggest that response switching results in early enhancements of effortful control mechanisms (N2 and ERN) at the expense of reductions in later response evaluation processes (Pe). Thus, when rules change, our attempts at control are accompanied by less attention to our actions.
切换任务如何影响我们监控和调整行为的能力？一方面，大量独立的研究考察了个体如何监控自己的行为并适应错误，另一方面，也考察了他们如何在两个或更多任务之间切换。然而，很少有研究探讨认知行为灵活性的这两个方面如何相互作用。也就是说，当任务规则发生变化时，个体如何监控自己的行为仍不得而知。本研究通过考察反应切换（一种涉及与特定刺激相关的反应切换的任务切换形式）的动作监控后果来解决这个问题。我们在参与者执行改良版字母 Flanker 任务时记录了事件相关脑电位（ERPs），在该任务中，刺激-反应（S-R）映射在块之间发生反转。具体来说，我们检查了与动作监控密切相关的三种 ERPs-N2、错误相关负波（ERN）和错误正波（Pe）。研究结果表明，S-R 反转块与动作监控脑活动的动态变化有关：N2 和 ERN 增强，而 Pe 减少。此外，参与者在 S-R 反转块中不太可能调整其错误后行为。总之，这些数据表明，反应切换导致努力控制机制（N2 和 ERN）的早期增强，而后期反应评估过程（Pe）的减少。因此，当规则发生变化时，我们的控制尝试伴随着对我们行为的关注减少。
