Department of Physiological Psychology, University of Salzburg, Austria.
Neuroimage. 2012 Feb 15;59(4):3379-88. doi: 10.1016/j.neuroimage.2011.11.010. Epub 2011 Nov 10.
In the present study we have tested the hypothesis that evoked traveling alpha waves are behaviorally significant. The results of a visual-semantic categorization task show that three early ERP components including the P1-N1 complex had a dominant frequency characteristic in the alpha range and behaved like traveling waves do. They exhibited a traveling direction from midline occipital to right lateral parietal sites. Phase analyses revealed that this traveling behavior of ERP components could be explained by phase-delays in the alpha but not theta and beta frequency range. Most importantly, we found that the speed of the traveling alpha wave was significantly and negatively correlated with reaction time indicating that slow traveling speed was associated with fast picture-categorization. We conclude that evoked alpha oscillations are functionally associated with early access to visual-semantic information and generate--or at least modulate--the early waveforms of the visual ERP.
在本研究中，我们检验了诱发的游走 alpha 波在行为上具有重要意义的假设。视觉语义分类任务的结果表明，包括 P1-N1 复合体在内的三个早期 ERP 成分具有 alpha 范围内的主导频率特征，表现得像游走波一样。它们表现出从中线枕部到右侧顶叶的游走方向。相位分析表明，ERP 成分的这种游走行为可以用 alpha 而不是 theta 和 beta 频率范围内的相位延迟来解释。最重要的是，我们发现游走 alpha 波的速度与反应时间呈显著负相关，表明较慢的游走速度与快速的图片分类有关。我们得出结论，诱发的 alpha 振荡与早期视觉语义信息的获取有关，并产生——或者至少调节——视觉 ERP 的早期波形。
