Min Byoung-Kyong, Busch Niko A, Debener Stefan, Kranczioch Cornelia, Hanslmayr Simon, Engel Andreas K, Herrmann Christoph S
Department of Biological Psychology, Otto-von-Guericke University, Magdeburg, Germany.
Int J Psychophysiol. 2007 Jul;65(1):58-68. doi: 10.1016/j.ijpsycho.2007.03.002. Epub 2007 Mar 12.
Some authors have proposed that event-related potentials (ERPs) are generated by a neuronal response which is additive to and independent of ongoing activity, others demonstrated that they are generated by partial phase-resetting of ongoing activity. We investigated the relationship between event-related oscillatory activity in the alpha band and prestimulus levels of ongoing alpha activity on ERPs. EEG was recorded from 23 participants performing a visual discrimination task. Individuals were assigned to one of three groups according to the amount of prestimulus total alpha activity, and distinct differences of the event-related EEG dynamics between groups were observed. While all groups exhibited an event-related increase in phase-locked (evoked) alpha activity, only individuals with sustained prestimulus alpha activity showed alpha-blocking, that is, a considerable decrease of poststimulus non-phase-locked alpha activity. In contrast, individuals without observable prestimulus total alpha activity showed a concurrent increase of phase-locked and non-phase-locked alpha activity after stimulation. Data from this group seems to be in favor of an additive event-related neuronal response without alpha-blocking. However, the dissociable EEG dynamics of total and evoked alpha activities together with a complementary simulation analysis indicated a partial event-related reorganization of ongoing brain activity. We conclude that both partial phase-resetting and partial additive power contribute dynamically to the generation of ERPs. The prestimulus brain state exerts a prominent influence on event-related brain responses.
一些作者提出，事件相关电位（ERP）是由一种与持续活动相加且独立的神经元反应产生的，另一些人则证明它们是由持续活动的部分相位重置产生的。我们研究了α波段中与事件相关的振荡活动和ERP上持续α活动的刺激前水平之间的关系。记录了23名执行视觉辨别任务的参与者的脑电图。根据刺激前总α活动量将个体分为三组之一，并观察到各组之间与事件相关的脑电图动态存在明显差异。虽然所有组在锁相（诱发）α活动中均表现出与事件相关的增加，但只有具有持续刺激前α活动的个体表现出α阻断，即刺激后非锁相α活动显著减少。相反，没有可观察到的刺激前总α活动的个体在刺激后表现出锁相和非锁相α活动同时增加。该组的数据似乎支持没有α阻断的相加性事件相关神经元反应。然而，总α活动和诱发α活动的可分离脑电图动态以及互补模拟分析表明，正在进行的大脑活动存在部分与事件相关的重组。我们得出结论，部分相位重置和部分相加功率都对ERP的产生有动态贡献。刺激前的脑状态对与事件相关的脑反应有显著影响。
