Send to:

Choose Destination
See comment in PubMed Commons below
Psychophysiology. 1997 Nov;34(6):721-5.

Suppression of sleepiness in drivers: combination of caffeine with a short nap.

Author information

  • 1Sleep Research Laboratory, Loughborough University, Leicestershire, UK.


Previous research has shown that caffeine and a < 15-min nap effectively and separately reduce sleepiness in drivers for 1 hr. In the present study, we examined in 12 sleepy individuals the treatments combined, taken during a 30-min break, prior to a longer (2 hr) continuous monotonous afternoon drive in a car simulator. Nonnap comparisons were 200 mg caffeine only and placebo. For placebo, driving incidents, subjective and electroencephalographic measures of sleepiness all reflected a mid-afternoon peak. This peak was significantly reduced by caffeine and eliminated by the combined treatment, which reduced incidents to 9% of placebo levels versus 34% of placebo levels for caffeine alone. Naps comprising "nonsleep dozing" were still effective.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Loading ...
    Write to the Help Desk