Pigeau R A, Frame A M
Defence and Civil Institute of Environmental Medicine, North York, Ont., Canada.
Electroencephalogr Clin Neurophysiol. 1992 Mar-Apr;84(2):101-9. doi: 10.1016/0168-5597(92)90014-3.
Reactivity to photic stimulation was studied in 16 subjects who were divided into 2 groups based on the relative amounts of spontaneous EEG alpha produced during a 4 min eyes-closed baseline condition. During the experimental session the subjects were presented with thirteen 1 min periods of sinusoidally modulated light stimulation at frequencies ranging from 2 Hz below their spontaneous peak alpha frequency (SPAF) to 2 Hz above in 0.33 Hz intervals. Using FFTs, steady-state visual evoked responses (VERs) were extracted from each subject's EEG for each condition. VER magnitude for high alpha subjects varied with the proximity of the stimulus frequency to the SPAF, the VER for low alpha subjects did not. Conversely, low alpha subjects showed a similar effect in side-band alpha activity (once the VER had been extracted) whereas high alpha subjects did not. The results are explained in terms of a possible difference in the coupling strength between thalamic and cortical alpha sources.
在16名受试者中研究了对光刺激的反应性，这些受试者根据在4分钟闭眼基线条件下产生的自发性脑电图α波的相对量分为两组。在实验过程中，向受试者呈现13个1分钟的正弦调制光刺激时段，频率范围从低于其自发性峰值α频率（SPAF）2Hz到高于该频率2Hz，间隔为0.33Hz。使用快速傅里叶变换（FFT），从每个受试者在每种条件下的脑电图中提取稳态视觉诱发电位（VER）。高α波受试者的VER幅度随刺激频率与SPAF的接近程度而变化，低α波受试者的VER则不然。相反，低α波受试者在边带α波活动中表现出类似的效应（一旦提取了VER），而高α波受试者则没有。结果根据丘脑和皮质α波源之间耦合强度可能存在的差异进行了解释。
