Do night naps impact driving performance and daytime recovery sleep?. (February 2017)

• Record Type: Journal Article
• Authors: Centofanti, Stephanie A.; Dorrian, Jillian; Hilditch, Cassie J.; Banks, Siobhan
• Is Part Of: Accident analysis and prevention. Volume 99:Part B (2017)
• Page Start: 416
• Page End: 421
• Publication Date: 2017-02
• Subjects: Shift work -- Simulated commute -- Fatigue -- Sleep architecture -- Nighttime naps -- Recovery; Accidents -- Prevention -- Periodicals; Accident Prevention -- Periodicals; Accidents -- Prévention -- Périodiques; 363.106
• DOI: 10.1016/j.aap.2015.11.009
• Languages: English
• ISSNs: 0001-4575

Abstract

Highlights: A 30 min or 10 min nighttime nap opportunity with a 10 min nap at 7am were implemented. Naps did not improve driving performance on a simulated morning commute. 30 min naps reduced SWS in subsequent daytime sleep, but 24 h SWS was preserved. Abstract: Short, nighttime naps are used as a fatigue countermeasure in night shift work, and may offer protective benefits on the morning commute. However, there is a concern that nighttime napping may impact upon the quality of daytime sleep. The aim of the current project was to investigate the influence of short nighttime naps (<30 min) on simulated driving performance and subsequent daytime recovery sleep. Thirty-one healthy subjects (aged 21–35 y; 18 females) participated in a 3-day laboratory study. After a 9-h baseline sleep opportunity (22:00 h–07:00 h), subjects were kept awake the following night with random assignment to: a 10-min nap ending at 04:00 h plus a 10-min nap at 07:00 h; a 30-min nap ending at 04:00 h; or a no-nap control. A 40-min driving simulator task was administered at 07:00 h and 18:30 h post-recovery sleep. All conditions had a 6-h daytime recovery sleep opportunity (10:00 h–16:00 h) the next day. All sleep periods were recorded polysomnographically. Compared to control, the napping conditions did not significantly impact upon simulated driving lane variability, percentage of time in a safe zone, or time to first crash on morning or evening drives ( p > 0.05). Short nighttime naps did not significantly affect daytime recovery total sleep time ( p > 0.05). Slow wave sleep (SWS) obtained during the 30-min nighttime nap resulted in a significant reduction in SWS during subsequent daytime recovery sleep ( p < 0.05), such that the total amount of SWS in 24-h was preserved. Therefore, short naps did not protect against performance decrements during a simulated morning commute, but they also did not adversely affect daytime recovery sleep following a night shift. Further investigation is needed to examine the optimal timing, length or combination of naps for reducing performance decrements on the morning commute, whilst still preserving daytime sleep quality.