Changes in frequency and amplitude of delta activity during sleep

Automatic detection of slow wave sleep using two channel electro-oculography

“…Therefore rather similar proportions of sleep stages are usually obtained by different scorers even if epoch-by-epoch inter-scorer agreements are rather low. The counting of individual slow waves has been suggested to quantify SWS sleep (Church et al, 1975;Hasan, 1996). Beside substantial accuracy in automatic online detection of SWS and non-SWS, also a more continuous parameter slow wave time (SWT), was estimated in this study (Fig.…”

Power and coherent oscillations distinguish REM sleep, stage 1 and wakefulness

“…Differences in absolute power spectra between stage 2, stage 3, stage 4, REM sleep and wakefulness have been documented (Church et al, 1975;Borbély et al, 1981;Uchida et al, 1994;Armitage, 1995;CorsiCabrera et al, 2000). Coherent activity between and within cortical hemispheres is important for binding together dispersed information into a unified cognitive experience and for understanding functional organization of the brain.…”

Sleep EEG Analysis by Linear Prediction: Frequency Changes of Slow-Wave Activity within NREM and REM Sleep Episodes in Healthy Men

“…It has already been noted that delta frequency, defined as frequency at which the maximum power is located, decreases as stage 4 progresses during the night, from NREMP 1 to NREMP 3 [29], We report here a different and more complex evolution of the DMF that appears to be a function of the NREM-REM sleep cycles. Our results indicate that DMF decreases during NREMP while it increases during REM.…”