Sleep is defined as unconsciousness from which the person can be aroused by sensory or other stimuli.It is to be distinguished from coma, which is unconsciousness from which the person cannot be aroused. There are multiple stages of sleep, from very light sleep to very deep sleep;sleep researchers also divide into two entirely different types of sleep that have different types of sleep that have different qualities, as follows.
Two types of Sleep:
During each night, a person goes through stages of two types of sleep that alternate with each other.They are called (1) slow-wave sleep,because in this type of sleep the brain waves are very strong very low frequency,as we discus later,and (2) rapid eye movement sleep (REM sleep), because in this type opf sleep the eyes undergo rapid movements despite the fact that the person is
still asleep.
Most sleep during each night is of the slow wave variety; this is the deep restful sleep that the person experiences during the first hour of sleep after having been awake for many hours.REM sleep, on the other hand, occurs in episodes that normally recurs about every 90 minutes.This type of sleep is not so restful and it is usually associated with vivid dreaming.
Two types of Sleep:
During each night, a person goes through stages of two types of sleep that alternate with each other.They are called (1) slow-wave sleep,because in this type of sleep the brain waves are very strong very low frequency,as we discus later,and (2) rapid eye movement sleep (REM sleep), because in this type opf sleep the eyes undergo rapid movements despite the fact that the person is
still asleep.
Most sleep during each night is of the slow wave variety; this is the deep restful sleep that the person experiences during the first hour of sleep after having been awake for many hours.REM sleep, on the other hand, occurs in episodes that normally recurs about every 90 minutes.This type of sleep is not so restful and it is usually associated with vivid dreaming.