Prospects of using electroencephalographic signatures of the chronoregulatory processes for meaningful, parsimonious and quantitative description of the sleep–wake sub-states

Abstract

The two traditional terminological systems for description of sleep–wake phenomena are based on criteria for visual scoring of sleep and on measuring EEG power densities in conventional frequency bands. There are serious limitations concerning the use of these terminologies for distinguishing different sleep–wake sub-states and transitions between them. Polysomnographic recordings obtained throughout all-night sleep (n = 14) and during 24-hour multiple sleep latency test (n = 32) were analyzed to demonstrate the possibilities (1) to uncover the universal three principal component structure of wake and sleep EEG spectra, (2) to predict such wake–sleep parameters as sleepiness, sleep latency, amount of any sleep stage, etc. from the three principal component scores, and (3) to link the magnitudes and time courses of these scores with the levels and kinetics of sleep–wake regulatory processes. This demonstration could lead to the development of a theoretically based terminological system allowing meaningful, parsimonious and quantitative description of sub-states along the sleep–wake continuum.