Achermann P, Borbély A A
Institute of Pharmacology, University of Zürich, Switzerland.
J Sleep Res. 1998;7 Suppl 1:36-41. doi: 10.1046/j.1365-2869.7.s1.6.x.
Coherence analysis of the human sleep electroencephalogram (EEG) was used to investigate relations between brain regions. In all-night EEG recordings from eight young subjects, the temporal evolution of power and coherence spectra within and between cerebral hemispheres was investigated from bipolar derivations along the antero-posterior axis. Distinct peaks in the power and coherence spectra were present in NREM sleep but not in REM sleep. They were situated in the frequency range of sleep spindles (13-14 Hz), alpha band (9-10 Hz) and low delta band (1-2 Hz). Whereas the peaks coincided in the power and coherence spectra, a dissociation of their temporal evolution was observed. In the low delta band, only power but not coherence showed a decline across successive NREM sleep episodes. Moreover, power increased gradually in the first part of a NREM sleep episode, whereas coherence showed a rapid rise. The results indicate that the intrahemispheric and interhemispheric coherence of EEG activity attains readily a high level in NREM sleep and is largely independent of the signal amplitude.
人类睡眠脑电图（EEG）的相干分析被用于研究脑区之间的关系。在对八名年轻受试者的整夜脑电图记录中，沿着前后轴的双极导联研究了大脑半球内和半球间功率谱和相干谱的时间演变。在非快速眼动睡眠（NREM）中，功率谱和相干谱中存在明显的峰值，但在快速眼动睡眠（REM）中则没有。它们位于睡眠纺锤波频率范围（13 - 14Hz）、α波段（9 - 10Hz）和低δ波段（1 - 2Hz）。虽然功率谱和相干谱中的峰值重合，但观察到它们的时间演变存在分离。在低δ波段，只有功率而不是相干性在连续的NREM睡眠阶段呈现下降。此外，在NREM睡眠阶段的第一部分，功率逐渐增加，而相干性则迅速上升。结果表明，脑电图活动的半球内和半球间相干性在NREM睡眠中很容易达到高水平，并且在很大程度上与信号幅度无关。
