Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU Dresden, Dresden 01307, Germany.
Faculty of Psychology, Shandong Normal University, Jinan 250014, China.
J Neurosci. 2023 Jun 21;43(25):4709-4724. doi: 10.1523/JNEUROSCI.2004-22.2023. Epub 2023 May 23.
Everyday tasks and goal-directed behavior involve the maintenance and continuous updating of information in working memory (WM). WM gating reflects switches between these two core states. Neurobiological considerations suggest that the catecholaminergic and the GABAergic are likely involved in these dynamics. Both of these neurotransmitter systems likely underlie the effects to auricular transcutaneous vagus nerve stimulation (atVNS). We examine the effects of atVNS on WM gating dynamics and their underlying neurophysiological and neurobiological processes in a randomized crossover study design in healthy humans of both sexes. We show that atVNS specifically modulates WM gate closing and thus specifically modulates neural mechanisms enabling the maintenance of information in WM. WM gate opening processes were not affected. atVNS modulates WM gate closing processes through the modulation of EEG alpha band activity. This was the case for clusters of activity in the EEG signal referring to stimulus information, motor response information, and fractions of information carrying stimulus-response mapping rules during WM gate closing. EEG-beamforming shows that modulations of activity in fronto-polar, orbital, and inferior parietal regions are associated with these effects. The data suggest that these effects are not because of modulations of the catecholaminergic (noradrenaline) system as indicated by lack of modulatory effects in pupil diameter dynamics, in the inter-relation of EEG and pupil diameter dynamics and saliva markers of noradrenaline activity. Considering other findings, it appears that a central effect of atVNS during cognitive processing refers to the stabilization of information in neural circuits, putatively mediated via the GABAergic system. Goal-directed behavior depends on how well information in short-term memory can be flexibly updated but also on how well it can be shielded from distraction. These two functions were guarded by a working memory gate. We show how an increasingly popular brain stimulation techniques specifically enhances the ability to close the working memory gate to shield information from distraction. We show what physiological and anatomic aspects underlie these effects.
日常任务和目标导向行为涉及到工作记忆 (WM) 中信息的维护和持续更新。WM 门控反映了这两种核心状态之间的转换。神经生物学考虑表明，儿茶酚胺能系统和 GABA 能系统可能参与这些动态变化。这两种神经递质系统都可能是耳穴经皮迷走神经刺激 (atVNS) 的作用基础。我们在一项随机交叉研究设计中，在健康的男性和女性中，检查了 atVNS 对 WM 门控动力学及其潜在神经生理和神经生物学过程的影响。我们表明，atVNS 特异性地调节 WM 门控关闭，从而特异性地调节使 WM 中的信息得以维持的神经机制。WM 门控打开过程不受影响。atVNS 通过调节 EEGα波段活动来调节 WM 门控关闭过程。在 WM 门控关闭过程中，当涉及刺激信息、运动反应信息以及携带刺激-反应映射规则的信息分数的 EEG 信号中的活动簇时，情况就是如此。EEG 波束形成显示，额叶极、眶额和下顶叶区域活动的调节与这些效应有关。这些数据表明，这些效应不是由于儿茶酚胺（去甲肾上腺素）系统的调节所致，因为瞳孔直径动力学的调节作用、EEG 和瞳孔直径动力学的相互关系以及去甲肾上腺素活动的唾液标记物都没有显示出调节作用。考虑到其他发现，似乎 atVNS 在认知处理过程中的中枢作用是指通过 GABA 能系统稳定神经回路中的信息。目标导向行为取决于短期记忆中的信息在多大程度上可以灵活更新，也取决于信息在多大程度上可以免受干扰。这两个功能由一个工作记忆门来保护。我们展示了一种越来越流行的脑刺激技术如何特异性地增强关闭工作记忆门以屏蔽信息免受干扰的能力。我们展示了这些效应的基础是什么生理和解剖方面。
