Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.
School of Psychology, University of Birmingham, Birmingham, United Kingdom.
Sci Rep. 2018 Feb 14;8(1):2990. doi: 10.1038/s41598-018-20423-z.
Many studies have now consistently reported that the phase angle of ongoing oscillatory activity (measured using EEG/MEG), at time of stimulus presentation influences detection when stimuli are near-threshold. However, studies examining whether the adjustment of the phase angle of oscillations is under top-down attentional control have thus far yielded conflicting results. A possible source for the discrepancy could be that the estimation of the phase of ongoing oscillations as well as its uniformity across trials could be affected by task induced changes in the power of oscillations or concurrent evoked responses. One measure, Inter-Trial Phase-Locking (ITPC), or the uniformity of phase angles across trials, is particularly vulnerable to these factors. Here, using various simulations modelling the common task induced changes in the EEG reported in the literature, we demonstrate that apparent changes in Inter-Trial Phase-Locking of oscillatory activity can occur independent of any actual change in the phase of the ongoing activity.
许多研究现在一致报告说，在刺激呈现时正在进行的振荡活动（使用 EEG/MEG 测量）的相位角会影响近阈值刺激的检测。然而，目前还没有研究检查调整振荡的相位角是否受到自上而下的注意力控制。出现差异的一个可能原因是，正在进行的振荡的相位估计及其在试验中的一致性可能会受到振荡功率或并发诱发反应的任务诱导变化的影响。一种度量标准，即试验间相位锁定（ITPC）或试验间相位角的一致性，特别容易受到这些因素的影响。在这里，我们使用各种模拟来模拟文献中报告的常见任务诱导的 EEG 变化，我们证明，正在进行的活动的相位没有实际变化的情况下，振荡活动的试验间相位锁定也可能会出现明显变化。
