1990/01/01 by Torbjörn Åkerstedt, Mats Gillberg · 4 citations
Medicine · Neuroscience · Psychology · #Ambulatory #Audiology #Electroencephalography #Electrooculography #Eyes open #Internal medicine #Medicine #Neuroscience #Polysomnography #Psychiatry #Psychology #Sleep Stages #Sleep and Wakefulness Research #Sleep and Work-Related Fatigue #Sleep and related disorders #Somnolence #Vigilance (psychology)
paper · doi:10.3109/00207459008994241
crossref issued 1990/01/01 · crossref published 1990/01/01 · crossref published-print 1990/01/01 · openalex publication_date 1990/01/01 · crossref published-online 2009/07/07 · crossref created 2009/12/07 · crossref deposited 2019/05/24 · openalex created_date 2025/10/10 · crossref indexed 2026/08/01 · openalex updated_date 2026/08/05
Eight subjects were kept awake and active overnight in a sleep lab isolated from environmental time cues. Ambulatory EEG and EOG were continuously recorded and sleepiness ratings carried out every two hours as was a short EEG test session with eyes open for 5 min and closed for 2 min. The EEG was subjected to spectral analysis and the EOG was visually scored for slow rolling eye movements (SEM). Intrusions of SEM and of alpha and theta power density during waking, open-eyed activity strongly differentiated between high and low subjective sleepiness (the differentiation was poorer for closed eyes) and the mean intraindividual correlations between subjective and objective sleepiness were very high. Still, the covariation was curvilinear; physiological indices of sleepiness did not occur reliably until subjective perceptions fell between "sleepy" and "extremely sleepy-fighting sleep"; i.e. physiological changes due to sleepiness are not likely to occur until extreme sleepiness is encountered. The results support the notion that ambulatory EEG/EOG changes may be used to quantify sleepiness.