Stroganova T A, Posikera I N, Prokof'ev A O, Morozov A A, Obukhov Iu V, Morozov V A
Zh Vyssh Nerv Deiat Im I P Pavlova. 2009 Nov-Dec;59(6):660-72.
We examined the changes in the phase-locked and total alpha oscillations of EEG during perception of illusory (Kanizsa square) and non-illusory images in 16 healthy adults. We applied a wavelet-based time-frequency analysis to compute alpha band power, statistical evaluation was performed using repeated-measures ANOVA and the non-parametric multi-way analysis. Results showed that both stimuli provoked an initial increase of total alpha power emerging not later than in 100 ms after the stimulus onset. The increase was caused by the phase-locked alpha response, and the illusory contour was systematically followed by a higher level of alpha power than the non-illusory one. Further suppression of total alpha power occurred within the time window of 200-500 ms after the stimulus onset and did not depend on the stimulus type. Both stages of the total alpha response were more prominent over the parieto-occipito-temporal scalp areas. We hypothesize that the first stage of alpha response is related to the modulation of the activity of neural circuits participating in processing of a coherent pattern whereas a later suppression of total alpha power links to the orienting processes.
我们研究了16名健康成年人在感知虚幻（卡尼萨方块）和非虚幻图像期间脑电图（EEG）中锁相和总阿尔法振荡的变化。我们应用基于小波的时频分析来计算阿尔法频段功率，使用重复测量方差分析和非参数多因素分析进行统计评估。结果表明，两种刺激均引发总阿尔法功率的初始增加，且不迟于刺激开始后100毫秒出现。这种增加是由锁相阿尔法反应引起的，并且虚幻轮廓之后的阿尔法功率水平系统地高于非虚幻轮廓。在刺激开始后的200 - 500毫秒时间窗口内发生了总阿尔法功率的进一步抑制，且不依赖于刺激类型。总阿尔法反应的两个阶段在顶枕颞头皮区域更为显著。我们推测，阿尔法反应的第一阶段与参与处理连贯模式的神经回路活动的调制有关，而总阿尔法功率的后期抑制与定向过程相关。
