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The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation
Controlled laboratory experiment (n=48 healthy adults): 14 nights at 4 h or 6 h time in bed produced cumulative dose-dependent cognitive deficits comparable to up to two nights of total sleep deprivation, while subjective sleepiness plateaued—suggesting limited awareness of performance impairment.
Design
- Chronic restriction: randomised 4 h, 6 h, or 8 h time in bed × 14 nights (+ baseline/recovery)
- Total sleep deprivation: 0 h × 3 nights comparator arm
- n = 48 healthy adults (21–38 y); intensive behavioural/PSG monitoring
Headline interpretation (abstract)
- 6 h/night or less sustained deficits in waking neurobehavioural performance on all tasks—authors frame as equivalent to ≤2 nights of total sleep loss in severity
- Subjective sleepiness rose acutely then changed little between 6 h vs 4 h, diverging from objective performance trajectories (“unaware of deficits” theme)
- Homeostatic EEG delta responded acutely to restriction with little further change across 14 nights—physiology did not mirror cumulative cognitive decline
- Lapse model: behavioural alertness lapses scaled with cumulative wakefulness beyond ~15.84 h (SE 0.73 h) across restriction and TSD modes
Evidence hygiene
Highly controlled young-adult sample—generalisation to older adults, shift workers, and clinical sleep disorders requires caution; not a sleep extension efficacy trial.
Publication
Van Dongen HP, Maislin G, Mullington JM, Dinges DF. Sleep. 2003 Mar 15;26(2):117-129. PMID 12683469.
Outcomes
- Chronic restriction to 4 h or 6 h TIB for 14 nights caused cumulative dose-dependent deficits in cognitive performance; authors state severity comparable to up to 2 nights of total sleep deprivation.
- Subjective sleepiness increased acutely then showed only small further increases and did not significantly separate 6 h vs 4 h conditions despite widening objective impairment.