Definition of non-REM sleep
: a state of sleep that occurs regularly during a normal period of sleep with intervening periods of REM sleep and is characterized by delta wave brain activity, little dreaming, and a reduced level of autonomic physiological activity
Non-REM sleep is a quiet sleep state. The muscles are relaxed but maintain some tone, breathing is regular, the cerebral cortex generates high-voltage waves, and consumption of energy by the brain is minimal.— Jerome M. Siegel For most people the few dreams found in non-REM sleep tend to have a rather thought-like character. During REM sleep, on the other hand, dreams occur more frequently and usually have a perceptual vividness …— Francis Crick et al. NREM sleep … is crucial to memory retention, and to acquiring and refining our motor skills.— David Kamp
— compare rem sleep, slow-wave sleep
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Merriam-Webster unabridged
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Time Traveler for non-REM sleep
The first known use of non-REM sleep was in 1963
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