The other basic state of sleep is NREM sleep or non-rapid eye movement sleep.
Dreaming sleep is notable for the presence of rapid eye movement (REM).
Dreams do not typically occur during other states of sleep.
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Dreams sleep occurs cyclically several times during sleep, but it comprises the smallest portion of thesleep cycle.
Non-Dreaming Sleep
Dreaming sleep, or REM is one of the two basic states of sleep.
The other basic state of sleep is non-rapid eye movement sleep or NREM sleep.
NREM is also referred to as non-dreaming sleep, as dreams do not occur during this state of sleep.
Cycles of Sleep
REM and NREM sleep alternate incyclesthroughout the night.
Generally, there are four to six different cycles of NREM sleep per night.
These cycles of NREM sleep account for the largest portion of overall sleep for the night.
The cycles of NREM sleep are followed by intervals of REM sleep, which is extremely deep sleep.
Typically, sleep cycles last about 90 minutes.
In other words, it takes a while for deep sleep to take over in an evening.
For this reason, REM sleep is not typically achieved during brief naps.
Frequent disturbance of REM sleep may contribute tofalse awakenings.
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