Time-of-day mediates the influences of extended wake and sleep restriction on simulated driving

Raymond W. Matthews, Sally A. Ferguson, Xuan Zhou, Charli Sargent, David Darwent, David J. Kennaway, Gregory D. Roach

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33 Citations (Scopus)


Although a nonlinear time-of-day and prior wake interaction on performance has been well documented, two recent studies have aimed to incorporate the influences of sleep restriction into this paradigm. Through the use of sleep-restricted forced desynchrony protocols, both studies reported a time-of-day×sleep restriction interaction, as well as a time-of-day×prior wake×sleep dose three-way interaction. The current study aimed to investigate these interactions on simulated driving performance, a more complex task with ecological validity for the problem of fatigued driving. The driving performance of 41 male participants (mean±SD: 22.8 ±2.2 yrs) was assessed on a 10-min simulated driving task with the standard deviation of lateral position (SDLAT) measured. Using a between-group design, participants were subjected to either a control condition of 9.33h of sleep18.66h of wake, a moderate sleep-restriction (SR) condition of 7h of sleep21h of wake, or a severe SR condition of 4.66h of sleep23.33h of wake. In each condition, participants were tested at 2.5-h intervals after waking across 7×28-h d of forced desynchrony. Driving sessions occurred at nine doses of prior wake, within six divisions of the circadian cycle based on core body temperature (CBT). Mixed-models analyses of variance (ANOVAs) revealed significant main effects of time-of-day, prior wake, sleep debt, and sleep dose on SDLAT. Additionally, significant two-way interactions of time-of- day×prior wake and time-of-day×sleep debt, as well as significant three-way interactions of time-of-day×prior wake×sleep debt and time-of-day×sleep debt×sleep dose were observed. Although limitations such as the presence of practice effects and large standard errors are noted, the study concludes with three findings. The main effects demonstrate that extending wake, reducing sleep, and driving at poor times of day all significantly impair driving performance at an individual level. In addition to this, combining either extended wake or a sleep debt with the early morning hours greatly decreases driving performance. Finally, operating under the influence of a reduced sleep dose can greatly decrease performance at all times of the day. (Author correspondence: raymond.matthews@unisa.edu.au)

Original languageEnglish
Pages (from-to)572-579
Number of pages8
JournalChronobiology International
Issue number5
Publication statusPublished or Issued - Jun 2012


  • Circadian rhythm
  • Driving performance
  • Forced desynchrony
  • Prior wake
  • Sleep debt
  • Sleep dose

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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