Bright light combined with caffeine can improve driving performance and alertness of chronically sleep deprived young drivers, according to a QUT road safety study.
Dr Shamsi Shekari, from QUT’s Centre for Accident Research & Road Safety – Queensland (CARRS-Q) is presenting her findings at the 2016 International Conference on Traffic and Transport Psychology being held in Brisbane from August 2-5.
CARRS-Q and Griffith University are co-hosting the event which draws together international experts from across the globe to share the latest in road safety research with the aim of reducing road trauma.
As part of her PhD, Dr Shekari tested the novel and potentially effective use of bright light, using commercially available light glasses that emit a shortwave blue-green light, and caffeinated chewing gum on young drivers aged 18-25 in a driving simulator to see if it increased alertness during daytime driving.
“Light therapy is being used to adjust a person’s circadian rhythm in shift workers and pilots and offers the potential to reduce sleepiness,” she said.
“The study found there was a significant effect on driving performance, mostly when caffeine was used alone or combined with light.
“Drivers who were given just caffeine, or light and caffeine together had decreased side to side movement of the steering wheel and the vehicle, indicating better control of the vehicle and higher alertness.
“Drivers who were feeling some signs of sleepiness after sleep loss, felt less sleepy after receiving either light or caffeine, and even felt rather alert after receiving the combination of both.”
Dr Shekari said the two-week study included monitoring sleep-wake patterns, with a normal eight hours of time in bed in the first week being reduced by to seven hours in the second week to produce chronic sleep deprivation in the participants.
“On the last three days participants took test sessions which involved recording their brain and heart activity, reaction times, assessment of their sleepiness and two 50km-long simulated drives each day,” she said.
“To compare the effectiveness of the countermeasures, all participants were provided with inactive chewing gum and light in the first drive and randomised active chewing gum and light in the second drive.”