Department of Psychosomatic Medicine and Psychotherapy, Medical Faculty, Medical Center - University of Freiburg, Freiburg, Germany.
Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.
Int J Psychophysiol. 2018 Jun;128:52-61. doi: 10.1016/j.ijpsycho.2018.03.020. Epub 2018 Mar 28.
While the contingent negative variation (CNV) has been the subject of extensive research over the last fifty years, the maximum duration during which such cortical negativity can be maintained has, to the best of our knowledge, never been systematically explored. Participants were presented with the classic S1-S2 paradigm task, where a warning stimulus (S1) acts as a cue for the appearance of an imperative stimulus (S2). A fast motor response was required upon S2 arrival. Inter-stimulus intervals (ISIs) of 2.5, 5, 7.5 and 10 s duration were presented in blocked fashion. Data was analysed using both EEG referenced to linked mastoids and the current source density (CSD) technique, which maximizes the cortical origin of the measured voltage. Mean late CNV (lCNV) amplitude was found to be significantly higher for fast reaction time (RT) trials when CSD data was split according to the median into 'fast' and 'slow' RT halves. Post-hoc comparisons showed that this RT effect was particularly strong for the 10 s condition. This may be explained by the lack of an lCNV component and thus of cortical negativity prior to S2 in the 10 s condition. Our results suggest that intervals of a duration between 7.5 and 10 s represent the upper boundary during which the lCNV component can be elicited.
虽然负向变程（CNV）在过去五十年中已经成为广泛研究的主题，但据我们所知，这种皮质负性可以维持的最大持续时间从未被系统地探索过。参与者接受了经典的 S1-S2 范式任务，其中警告刺激（S1）作为出现强制性刺激（S2）的提示。当 S2 到达时需要快速做出运动反应。以块的形式呈现持续时间为 2.5、5、7.5 和 10 秒的刺激间间隔（ISIs）。使用 EEG 参考链接乳突和电流源密度（CSD）技术对数据进行分析，该技术最大限度地提高了所测量电压的皮质起源。当根据中位数将 CSD 数据分为“快速”和“慢速”RT 半部分时，发现快速反应时间（RT）试验的平均晚期 CNV（lCNV）振幅明显更高。事后比较表明，这种 RT 效应在 10 秒条件下特别强烈。这可能是由于在 10 秒条件下，S2 之前缺乏 lCNV 成分，因此没有皮质负性。我们的结果表明，持续时间在 7.5 和 10 秒之间的间隔代表了可以引出 lCNV 成分的上限。
