Dissociating effects of global SWS disruption and healthy aging on waking performance and daytime sleepiness
John A Groeger1, Neil Stanley2, Stephen Deacon3
1Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK ; Department of Psychology, University of Hull, Hull, UK.
Study Objective:
To contrast the effects of slow wave sleep (SWS) disruption and age on daytime functioning.
Design:
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).
Setting:
Sleep research laboratory.
Participants:
44 healthy young (20-30 y), 35 middle-aged (40-55 y), and 31 older (66-83 y) men and women.
Interventions:
Acoustic stimulation contingent on appearance of slow waves.
Measurements And 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.
Related Concept Videos
01:24Sleep-Wake Cycles
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
01:13Insufficient Sleep and Sleep Deprivation
Sleep deprivation is a more severe form of sleep loss...
01:22Stages of Sleep
Before sleep begins, in wakefulness, the brain exhibits primarily beta waves, which are high in frequency and low in amplitude, indicating alertness...
01:11Understanding Sleep
The circadian rhythm, a nearly 24-hour cycle, is deeply influenced by environmental light cues. Light exposure directly affects the hypothalamus, which in turn regulates...
01:27Pharmacodynamics in Geriatric Patients: Effects of Age
01:17Sedatives and Hypnotics Drugs: Miscellaneous Agents
Melatonin congeners like ramelteon (Rozerem) and tasimelteon (Hetlioz) selectively bind to melatonin receptors (MT1 and MT2) and thus mimic the actions of melatonin, a hormone that regulates sleep-wake cycles. Tasimelteon is primarily used for non-24-hour sleep-wake disorder, common in blind patients. They are also used to treat conditions like insomnia...