大象传媒

Working practices, technology and the 24-hour culture combine to reduce our sleep. Scientists in Canada have launched the world's largest study of the effect of lack of sleep on the brain. They want people worldwide to do cognitive tests online, to see how the amount of sleep we get affects our ability to function. More information: www.worldslargestsleepstudy.com

Photo: Tired woman in a car
Credit: Getty Images