1. Bright light alone or combined with caffeine improves sleepiness in chronically sleep-restricted young drivers.
- Author
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Shekari Soleimanloo S, Garcia-Hansen V, White MJ, Huda MM, and Smith SS
- Subjects
- Adolescent, Adult, Caffeine, Humans, Sleep physiology, Sleepiness, Wakefulness physiology, Young Adult, Automobile Driving, Central Nervous System Stimulants pharmacology, Central Nervous System Stimulants therapeutic use
- Abstract
Background: Young drivers are over-involved in sleepiness-related crashes. The alerting effects of bright light offer a potential countermeasure for driver sleepiness, either replacing or in conjunction with current countermeasures such as the use of caffeine., Methods: Thirty young (18-25) chronically sleep-restricted drivers drove in a simulator under randomized conditions of continuous bright light ('Light,' 500 nm, 230μw/cm
2 ), caffeine ('Caffeine,' 100 mg caffeinated gum), or light and caffeine together ('Light + Caffeine'), after driving under a placebo condition ('Placebo,' decaffeinated gum, 555 nm light, 0.3 μW/cm2 ) on three consecutive days. Using mixed-effects linear models, the associations between these conditions and physiological outcomes (EEG alpha and theta power, heart rate, and beat-to-beat intervals), driving performance (lateral lane and steering-related outcomes and lateral acceleration), and subjective sleepiness was assessed., Results: Relative to Placebo, all conditions improved driving performance outcomes (P < 0.0001), with effects of Light + Caffeine equal to Light but greater than Caffeine. Light + Caffeine reduced EEG alpha power more than Light or Caffeine (P < 0.0006), but ECG outcomes were generally worse under all conditions relative to Placebo. Subjective sleepiness improved under the Light + Caffeine condition only (P < 0.0001)., Conclusions: Combining bright light and caffeine enhances their alerting effects on lateral lane variability and subjective sleepiness. A bright light could be a practical alternative to caffeine for sleepy drivers who avoid caffeine. The alerting effects of bright light could alleviate chronic community-level mild sleep restriction and provide on-road benefits to reduce severe injuries and fatal sleepiness-related crashes., (Crown Copyright © 2022. Published by Elsevier B.V. All rights reserved.)- Published
- 2022
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