Guevara M A, Lorenzo I, Arce C, Ramos J, Corsi-Cabrera M
Departamento de Psicofisiología, Facultad de Psicología, Universidad Nacional Autónoma de México, Mexico, D.F.
Sleep. 1995 May;18(4):257-65. doi: 10.1093/sleep/18.4.257.
Inter- (INTERr) and intrahemispheric (INTRAr) electroencephalographic (EEG) correlations were assessed in eight young male adults during wakefulness with eyes closed before going to sleep, and during stage 2, stage 4 and paradoxical sleep (PS) on the second night spent at the laboratory. Pearson product-moment correlations were calculated between EEG signals of every pair of electrodes (C3, C4, F3, F4, T3, T4) for six bands and for every 0.5 Hz from 1.5 to 15 Hz. Previous results of higher INTERr during sleep compared to during wakefulness were confirmed for the delta and theta bands during stage 2 sleep and PS and for sleep spindles during stage 2 sleep. The present results extend these findings to INTERr between F3 and F4 and during stage 4 sleep. INTRAr of 1.5-6.5 and 11-15 Hz was significantly higher during stages 2 and 4, whereas during PS INTRAr did not change. These data show that cortical changes during sleep are also observed in functional differentiation between cortical sites. Inter- and intrahemispheric differentiation is attenuated during stage 2 and 4 sleep, whereas during PS only inter-hemispheric differentiation is attenuated but intrahemispheric differentiation maintains similar levels of wakefulness. The attenuation of cortical differentiation may be of relevance for the understanding of mental activity changes during sleep.
在八名年轻男性成年人中，于睡前闭眼清醒状态下以及在实验室度过的第二晚的睡眠2期、4期和异相睡眠（PS）期间，评估了半球间（INTERr）和半球内（INTRAr）脑电图（EEG）相关性。计算了每对电极（C3、C4、F3、F4、T3、T4）的EEG信号在六个频段以及从1.5至15Hz每0.5Hz频率下的皮尔逊积差相关性。睡眠期间半球间相关性高于清醒期间这一先前结果，在睡眠2期和PS期间的δ和θ频段以及睡眠2期的睡眠纺锤波方面得到了证实。本研究结果将这些发现扩展至F3和F4之间以及睡眠4期的半球间相关性。在睡眠2期和4期，1.5 - 6.5Hz和11 - 15Hz的半球内相关性显著更高，而异相睡眠期间半球内相关性未发生变化。这些数据表明，睡眠期间的皮质变化也体现在皮质位点之间的功能分化上。在睡眠2期和4期，半球间和半球内分化减弱，而异相睡眠期间仅半球间分化减弱，但半球内分化维持与清醒时相似的水平。皮质分化的减弱可能与理解睡眠期间的心理活动变化相关。
