Sleep along with rapid eye movements (Rapid eye movement sleep: REM/REMS) one of the stages of sleep in mammals, in which the body is in deep sleep mode to take over, but the reaction of the brain in the Waking State.

during sleep AR Yi, the movements are very fast, with periods of 10 to 20 seconds, ... heart beats a little faster. and the metabolic rate of the brain to the extent of waking time arrives. In addition, during sleep AR Yi the Adam is almost completely paralyzed and can only be the heart, the diaphragm, etc. muscles. and muscles smooth (like muscles, intestines and blood vessels) is enabled like. In contrast, during sleep, non-AR Yi the eye movements to overall stops, breathing and heart rate to dramatically reduced, the muscles are lies. and the metabolic rate of the brain compared with the period of wakefulness between 25% to 30% reduced. He, that is the main characteristic of sleep, non-AR Yee all there brain in physical very evil. and major features of sleep AR Yi all there brain fully awake in the physical and more or less paralysis.