Nap and coffee : confirmation of their beneficial effects on night driving

A team from the University Hospital of Bordeaux confirmed in a study in a real situation the beneficial effects of coffee and, to a lesser extent, napping on night driving.
A team from the University Hospital of Bordeaux confirmed in a study in a real situation the beneficial effects of coffee and, to a lesser extent, napping on night driving.
Posted on the website of the CHU network, this study was conducted by Professor Peter Philip and his colleagues at the Laboratory of Cellular Physiology and pathophysiology of the CNRS led by Professor Bernard Bioulac .

His results confirm those obtained in previous work performed in a driving simulator , which showed that drinking coffee and take a nap allowed to recover and regain the necessary vigilance in night driving .

Twelve volunteers , aged 18 to 25 years, and have performed all four events each driving 200 kms imposed by researchers: the first between 17h and 18.30 ( reference path ) and the other three between 2 and 3:30 am , after drinking a " deca " or a bowl of instant coffee ( 200 mg caffeine) or after a nap for half an hour in a car parked on a parking area.

After the absorption of coffee, three quarters of the drivers had a driving similar to that they had had during the reference path . This proportion was still two-thirds when drivers had a nap, but fell to only 13% when they had had a " deca " , the researchers then observing up to 17 crossings white line.

If a cup of coffee and take a nap so help fight against lapses of attention and sleep responsible for 20 % of road accidents , the first option is more effective than the second, the authors say .

According to the latter, the caffeine would indeed both the homeostatic pressure , which aims to balance the time of awakening, and the chronobiological pressure to the biological clock that is independent of standby time . Nap, in turn, affects only the homeostatic pressure , lowering it , but not on the chronobiological pressure.

Nevertheless, people are not equal before sleep deprivation and how to remedy this, some better suited to nap and other coffee . At each of the known " cure " for which it is most sensitive.