REM sleep

noun

Definition of REM sleep

: a state of sleep that recurs cyclically with non-REM sleep several times during a normal period of sleep, is characterized especially by greatly depressed muscle tone, dreaming with vivid imagery, rapid eye movements, and increased neuronal activity in certain brain regions (such as the pons), and typically comprises up to 25% of time spent in sleep REM sleep, it soon became apparent, occurs in intervals throughout the night, usually four to six times, each lasting from ten minutes to an hour.— Martin Gardner People awakened during REM sleep usually report dreams with visual images and storylike narratives.— Lis Harris

called also paradoxical sleep, rapid eye movement sleep

— compare slow-wave sleep, non-REM sleep

First Known Use of REM sleep

1963, in the meaning defined above

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The first known use of REM sleep was in 1963

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Cite this Entry

“REM sleep.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/REM%20sleep. Accessed 23 Jan. 2022.

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More Definitions for REM sleep

REM sleep

noun

English Language Learners Definition of REM sleep

: a stage of sleep during which you dream and your eyes make quick movements

REM sleep

noun

Medical Definition of REM sleep

: a state of sleep that recurs cyclically with non-REM sleep several times during a normal period of sleep, is characterized especially by greatly depressed muscle tone, dreaming with vivid imagery, rapid eye movements, and increased neuronal activity in certain brain regions (as the pons), and typically comprises up to 25% of time spent in sleep REM sleep, it soon became apparent, occurs in intervals throughout the night, usually four to six times, each lasting from ten minutes to an hour.— Martin Gardner People awakened during REM sleep usually report dreams with visual images and storylike narratives.— Lis Harris

called also desynchronized sleep, paradoxical sleep, rapid eye movement sleep

— compare non-rem sleep

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