title: Time-of-day variations in different measures of sleepiness (MSLT, pupillography, and SSS) and their interrelations.
abstract: The aim of the present study is to analyze how well physiological measures of sleepiness derived from pupillography and the Multiple Sleep Latency Test correlate with a subjective measure, the Stanford Sleepiness Scale (SSS) score. The results are based on data from 12 healthy participants, who underwent these tests every 2 hr from 7:00 a.m. until 11:00 p.m. Sleep latencies were correlated with four different variables derived from pupillography and the SSS score. The results indicate that the physiologically based variables correspond very well. This is reflected by similar patterns of time-of-day variations, a good agreement at the group level, and correlations at the individual level, whereas the SSS shows a quite different pattern of variation. The two physiological measures of sleepiness seem to reflect the same aspect of the level of tonic central nervous activation, which is not correlated with the subjective feeling of sleepiness.
authors.affiliation: Interdisciplinary Sleep Clinic, Department of Psychiatry, Benjamin Franklin University Hospital, Free University of Berlin, Germany. heide.danker-hopfe@medizin.fu-berlin.de
authors.forename: H
authors.initials: H
authors.lastname: Danker-Hopfe
authors.forename: S
authors.initials: S
authors.lastname: Kraemer
authors.forename: H
authors.initials: H
authors.lastname: Dorn
authors.forename: A
authors.initials: A
authors.lastname: Schmidt
authors.forename: I
authors.initials: I
authors.lastname: Ehlert
authors.forename: W M
authors.initials: WM
authors.lastname: Herrmann
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011680:Pupil / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology*; D013997:Time Factors