title: Dissociating effects of global SWS disruption and healthy aging on waking performance and daytime sleepiness.
abstract: OBJECTIVE
  To contrast the effects of slow wave sleep (SWS) disruption and age on daytime functioning.
  
  
  METHODS
  Daytime functioning was contrasted in three age cohorts, across two parallel 4-night randomized groups (baseline, two nights of SWS disruption or control, recovery sleep).
  
  
  METHODS
  Sleep research laboratory.
  
  
  METHODS
  44 healthy young (20-30 y), 35 middle-aged (40-55 y), and 31 older (66-83 y) men and women.
  
  
  METHODS
  Acoustic stimulation contingent on appearance of slow waves.
  
  
  RESULTS
  Cognitive performance was assessed before sleep latency tests at five daily time-points. SWS disruption resulted in less positive affect, slower or impaired information processing and sustained attention, less precise motor control, and erroneous implementation, rather than inhibition, of well-practiced actions. These performance impairments had far smaller effect sizes than the increase in daytime sleepiness and differed from baseline to the same extent for each age group. At baseline, younger participants performed better than older participants across many cognitive domains, with largest effects on executive function, response time, sustained attention, and motor control. At baseline, the young were sleepier than other age groups.
  
  
  CONCLUSIONS
  SWS has been considered a potential mediator of age-related decline in performance, although the effects of SWS disruption on daytime functioning have not been quantified across different cognitive domains nor directly compared to age-related changes in performance. The data imply that two nights of SWS disruption primarily leads to an increase in sleepiness with minor effects on other aspects of daytime functioning, which are different from the substantial effects of age.
authors.affiliation: Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK ; Department of Psychology, University of Hull, Hull, UK.
authors.forename: John A
authors.initials: JA
authors.lastname: Groeger
authors.affiliation: Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: Stanley
authors.affiliation: H. Lundbeck A/S, Copenhagen, Denmark.
authors.forename: Stephen
authors.initials: S
authors.lastname: Deacon
authors.affiliation: Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
authors.forename: Derk-Jan
authors.initials: DJ
authors.lastname: Dijk
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000339:Affect / Q000502:physiology; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001143:Arousal / Q000502:physiology; D001288:Attention / Q000502:physiology; D015331:Cohort Studies; D056344:Executive Function / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D017286:Polysomnography; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000503:physiopathology*; D012894:Sleep Stages / Q000502:physiology; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult
keywords: aging; cognition; daytime functioning; sleep; slow wave sleep