Michel C M, Lehmann D, Henggeler B, Brandeis D
Department of Neurology, University Hospital, Zurich, Switzerland.
Electroencephalogr Clin Neurophysiol. 1992 Jan;82(1):38-44. doi: 10.1016/0013-4694(92)90180-p.
FFT dipole approximation and 3-dimensional dipole modelling were used to determine the locations of the equivalent dipole model sources of the delta, theta, alpha, beta-1 and beta-2 frequency bands in 13 normal subjects during resting. From each subject, 2 successive data sets were analysed, each consisting of 10 epochs of 2 sec randomly collected during 30 min. ANOVAs showed that over subjects, the source locations of EEG frequency bands differed significantly in the vertical and antero-posterior dimensions. Results of data set 2 confirmed those of data set 1. The source of delta was deepest and most anterior, theta more posterior and less deep, alpha most posterior and highest on the vertical dimension, beta-1 deeper and slightly more anterior than alpha, and beta-2 again more anterior and deeper than beta-1. Thus, the depth of source location was not linearly related to temporal frequency. The sources of all 5 bands were oriented in the sagittal direction; delta mean fields had steeper gradients anteriorly, alpha and beta-1 posteriorly. The power map for any frequency was well described by a single phase angle. The results indicate that the different EEG frequency bands during a given EEG epoch are generated by neural populations in different brain locations.
采用快速傅里叶变换（FFT）偶极子近似法和三维偶极子建模法，确定13名正常受试者静息状态下δ、θ、α、β1和β2频段等效偶极子模型源的位置。对每名受试者的2个连续数据集进行分析，每个数据集由在30分钟内随机采集的10个2秒时长的时段组成。方差分析表明，在不同受试者中，脑电图频段的源位置在垂直维度和前后维度上存在显著差异。数据集2的结果证实了数据集1的结果。δ频段的源最深且最靠前，θ频段更靠后且深度稍浅，α频段在垂直维度上最靠后且最高，β1频段比α频段更深且稍靠前，β2频段比β1频段更靠前且更深。因此，源位置的深度与时间频率并非线性相关。所有5个频段的源均沿矢状方向排列；δ平均场在前部具有更陡的梯度，α和β1平均场在后部具有更陡的梯度。任何频率的功率图都可以用一个单一的相位角很好地描述。结果表明，在给定的脑电图时段内，不同的脑电图频段由不同脑区的神经群体产生。
