The science of sleep

die, a bigger slice of your existence will have passed in this state than in raising children, playing games, listening to music, or any other activity that humanity values highly." Why is it necessary to spend quite so long in this unconscious state? Unlike breathing or eating, the biological benefits of sleep are not immediately obvious. It is a behaviour that can be found remarkably far back down the evolutionary ladder. In all creatures, sleep generally involves a cessation of physical activity and reduction of sensory awareness for regular periods. Like us, other animals are kept awake by stimulants such as caffeine and sleep more as babies.