Houshmand Chatroudi Amirmahmoud, Rostami Reza, Nasrabadi Ali Motie, Yotsumoto Yuko
Department of Life Sciences, The University of Tokyo, Tokyo, Tokyo, Japan.
Faculty of Psychology and Educational Sciences, University of Tehran, Tehran, Tehran, Iran.
PLoS One. 2021 Feb 22;16(2):e0247416. doi: 10.1371/journal.pone.0247416. eCollection 2021.
Early electroencephalographic studies that focused on finding brain correlates of psychic events led to the discovery of the P300. Since then, the P300 has become the focus of many basic and clinical neuroscience studies. However, despite its wide applications, the underlying function of the P300 is not yet clearly understood. One line of research among the many studies that have attempted to elucidate the underlying subroutine of the P300 in the brain has suggested that the physiological function of the P300 is related to inhibition. While some intracranial, behavioral, and event-related potential studies have provided support for this theory, little is known about the inhibitory mechanism. In this study, using alpha event-related desynchronization (ERD) and effective connectivity, based on the causal (one-way directed) relationship between alpha ERD and P300 sources, we demonstrated that P300's associated inhibition is implemented at a higher information processing stage in a localized brain region. We discuss how inhibition as the primary function of the P300 is not inconsistent with 'resource allocation' and 'working memory updating' theories about its cognitive function. In light of our findings regarding the scope and information processing stage of inhibition of the P300, we reconcile the inhibitory account of the P300 with working memory updating theory. Finally, based on the compensatory behavior of alpha ERD at the time of suppression of the P300, we propose two distinct yet complementary working memory mechanisms (inhibition and desynchronizing excitation) that render target perception possible.
早期专注于寻找心理事件大脑关联的脑电图研究促成了P300的发现。从那时起，P300就成为了许多基础和临床神经科学研究的焦点。然而，尽管其应用广泛，P300的潜在功能尚未得到清晰理解。众多试图阐明P300在大脑中潜在子程序的研究中有一条研究路线表明，P300的生理功能与抑制有关。虽然一些颅内、行为和事件相关电位研究为这一理论提供了支持，但对抑制机制却知之甚少。在本研究中，基于α事件相关去同步化（ERD）和有效连接性，利用α ERD与P300源之间的因果（单向定向）关系，我们证明了P300相关的抑制作用在局部脑区的更高信息处理阶段得以实现。我们讨论了作为P300主要功能的抑制作用如何与关于其认知功能的“资源分配”和“工作记忆更新”理论并不矛盾。鉴于我们关于P300抑制作用的范围和信息处理阶段的研究结果，我们将P300的抑制解释与工作记忆更新理论进行了调和。最后，基于P300抑制时α ERD的补偿行为，我们提出了两种不同但互补的工作记忆机制（抑制和去同步化兴奋），使目标感知成为可能。
