Barry Robert J
Brain & Behaviour Research Institute and School of Psychology, University of Wollongong, Wollongong 2522, Australia.
Biol Psychol. 2009 Mar;80(3):292-9. doi: 10.1016/j.biopsycho.2008.10.009. Epub 2008 Nov 6.
Current views of the genesis of the event-related potential (ERP) contrast the phase-reset and evoked activity models. In the former, a portion of the ongoing electroencephalographic (EEG) activity becomes phase-locked at stimulus onset; in the latter, processing in the brain contributes additional time-locked activity at each trial. This study aimed to explore these perspectives in an auditory Go/NoGo task. The interactions between these processes were examined using the amplitudes and topographies of pre- and post-stimulus EEGs in traditional bands, and the averaged ERPs, together with time-frequency analysis. Results indicate that both evoked activity and phase locking of ongoing EEG activity contribute substantially to the different Go and NoGo ERP components. Phase locking contributes most strongly to the early exogenous ERP components, with evoked brain activity related to cognitive processing contributing strongly to the endogenous ERP components. Evidence also suggests that extensive phase realignments may generate the power increases associated with early exogenous components. It is concluded that exogenous ERP components arise substantially from phase-resetting mechanisms involving ongoing EEG activity. In contrast, the endogenous components are substantially produced by evoked activity in various frequency bands, and their differences reflect differential cortical processing required for appropriate responding to the Go vs. NoGo stimuli.
当前对事件相关电位（ERP）起源的看法对比了相位重置和诱发活动模型。在前者中，一部分正在进行的脑电图（EEG）活动在刺激开始时变得相位锁定；在后者中，大脑中的处理过程在每次试验中都会产生额外的时间锁定活动。本研究旨在通过听觉Go/NoGo任务探索这些观点。使用传统频段中刺激前和刺激后EEG的幅度和地形图、平均ERP以及时频分析来检查这些过程之间的相互作用。结果表明，诱发活动和正在进行的EEG活动的相位锁定都对不同的Go和NoGo ERP成分有很大贡献。相位锁定对早期外源性ERP成分贡献最大，而与认知处理相关的诱发脑活动对内源性ERP成分贡献很大。证据还表明，广泛的相位重新调整可能会产生与早期外源性成分相关的功率增加。得出的结论是，外源性ERP成分主要源于涉及正在进行的EEG活动的相位重置机制。相比之下，内源性成分主要由不同频段的诱发活动产生，它们的差异反映了对Go与NoGo刺激做出适当反应所需的不同皮质处理。
