This article is about sleep in humans. Sleep architecture”, “Waking up”, “Asleep”, and “Slept” redirect here. Sleep is associated with a state of muscle relaxation cultural anthropology the human challenge 14th edition free pdf reduced perception of environmental stimuli.
The diverse purposes and mechanisms of sleep are the subject of substantial ongoing research. An artist’s creative illustration depicting REM sleep. The most pronounced physiological changes in sleep occur in the brain. Especially during non-REM sleep, the brain uses significantly less energy during sleep than it does in waking. In other words, sleeping persons perceive fewer stimuli. However, they can generally still respond to loud noises and other salient sensory events.