Animal studies have shown that the @entity25 in the frequency range of spindles and slow-waves, and in the gamma band occur synchronously over large parts of the cerebral cortex. Coherence analysis was used to investigate these oscillations in the @entity1 sleep electroencephalogram. In all-night electroencephalogram recordings from eight young subjects power and coherence spectra within and between cerebral hemispheres were computed from bipolar derivations placed bilaterally along the antero-posterior @entity2270 . The 0.75-50 Hz range was examined with a resolution of 0.25 Hz. Distinct peaks in coherence were present in non-rapid eye @entity10522 but not in rapid eye @entity10522 . The most prominent and consistent peak was seen in the range of sleep spindles (13-14 Hz), and additional peaks were present in the alpha band (9-10 Hz) and low delta band (1-2 Hz). Whereas coherence in the spindle range was highest in stage 2, the alpha peak was most prominent in slow-wave sleep (stages 3 and 4). Interhemispheric coherence at 30 Hz was higher in rapid eye @entity10522 than in non-rapid eye @entity10522 . There were also marked sleep state-independent regional differences. Coherence between homologous interhemispheric derivations was high in the low frequency range and declined with increasing frequencies, whereas coherence of intrahemispheric and non-homologous interhemispheric derivations was at a low level throughout the spectra. It is concluded that coherence analysis may provide insights into large-scale functional connectivities of brain regions during sleep. The high coherence of sleep spindles is an indication for their widespread and quasi-synchronous occurrence throughout the cortex and may point to their specific role in the sleep process.

Coherence analysis of the XXXX sleep electroencephalogram.

@entity1 :: ('9606', 'Species') :: ['human'] @entity10522 :: ('MESH:D020189', 'Disease') :: ['movement sleep'] @entity2270 :: ('MESH:C566610', 'Disease') :: ['axis'] @entity25 :: ('MESH:D012893', 'Disease') :: ['sleep-related oscillations']
@entity1 :: (9606,Species) :: ['human']
