A new international study has thrown up some terrifying evidence for anybody who's ever got into the car while tired. It found that taking getting behind the wheel while sleep-deprived could be just as dangerous as driving while intoxicated.
The study, lead by Dr Itzhak Fried from the University of California, found that parts of the brain can shut themselves off in people who are particularly tired – leading people to struggle to connect visual information with conscious thought.
Dr Fried said: "We discovered that starving the body of sleep also robs neurons of the ability to function properly. This paves the way for cognitive lapses in how we perceive and react to the world around us."
During the study, 12 people were kept awake all night and then asked to categorise a variety of images as fast as possible. Unsurprisingly, as tiredness levels increased, the participants struggled more with the task. However, the study found that the brain cells actually slowed down, too.
Dr Yuval Nir from Tel Aviv University said: "We were fascinated to observe how sleep deprivation dampened brain cell activity. Unlike the usual rapid reaction, the neurons responded slowly, fired more weakly and their transmissions dragged on longer than usual."
This could have severe issues when driving. Dr Nir suggested a situation where a pedestrian steps out in front of a driver: "The very act of seeing the pedestrian slows down in the driver's overtired brain. It takes longer for his brain to register what he's perceiving."
Dr Fried compared driving while tired to drink-driving, saying: "Inadequate sleep exerts a similar influence on our brain to drinking too much. Yet no legal or medical standards exist for identifying overtired drivers on the road the same way we target drunk drivers."