P3, Decision, and Gestalt Circle: Towards Understanding the Function of the P3b Component of the Event-Related EEG Potential as a Bridge Between Perception and Action

额叶中央P3a和顶叶P3b的P3复合体是从头皮记录到的人类脑电电位中最显著的成分之一。然而，即使经过数百项研究，测量为P3b的皮质激活所起的作用仍然不是很清楚。经典的假设是，P3b表示工作记忆的更新，只受知觉参数的影响，而不受行为反应参数的影响。尽管这些假设长期以来都是错误的，但仍然没有被更好的建议所取代。最近的一种观点认为，P3b与对感知到的刺激做出反应的决定过程有关。但这种关系的确切性质仍然不清楚。这个项目的目的是进一步讨论，首先是通过仔细审查P3b和刺激反应联系之间长期被忽视的关系。我们最近的初步研究导致了这一工作假说：P3b反映了现有刺激-反应环节的激活。P3b将越大，这种刺激-反应联系越强，目前它被启动的越少。拟议的实验将通过研究通过将反应与感知分离而对P3b施加的影响来测试和完善这一假设。这将通过修改用于测量P3的两个基本范式来完成：古怪任务和事件预测。将应用新的数据分析方法。最终目标是得出详细的、基于证据的P3b理论。希望通过对P3b的理解，也能更好地理解P3b所反映的将知觉与行动联系在一起的综合认知功能。

The P3 complex of fronto-central P3a and parietal P3b is among the most conspicuous components of the human EEG potential as may be recorded from the scalp. Yet, even after hundreds of studies, the role played by the cortical activation measured as P3b is still not well understood. Classical assumptions are that P3b indicates updating of working memory and is affected by perceptual parameters only, rather than by parameters of behavioral responses. Though falsified since long, these assumptions have still not been replaced by better suggestions. A more recent view holds that P3b is related to the process of decision about what to do in response to perceived stimuli. But the exact nature of this relationship has remained unclear.This project is designed to take this discussion further, above all by scrutinizing the long-neglected relation between P3b and stimulus-response-links. Our recent preliminary studies have led to this working hypothesis: P3b reflects activation of an existing stimulus-response link. P3b will be the larger, the stronger is this stimulus-response link and the less it has presently been primed.The proposed experiments will test and refine this hypothesis through studying effects exerted on P3b by decoupling responses from perception. This will be done in modifications of the two basic paradigms used for measuring P3: the oddball task and the prediction of events. New data-analytic methods will be applied.The final aim is to arrive at a detailed, evidence-based theory of P3b. It is hoped that, by understanding P3b, the integrative cognitive function reflected by P3b, tying perception and action together, will be better understood as well.