sleep stages
type: Concept
narrower: REM sleep

concepts
type: Collection
type: ConceptGroup
member: REM sleep

REM sleep
definition: The terms rapid eye movement (REM) and nonrapid eye movement (NREM) were first coined by William Dement in the 1950s; he went on to become a leader in the field of sleep research. REM sleep occurs in the fifth stage of sleep and is associated with dreaming. [Source: The SAGE Glossary of the Social and Behavioral Sciences; REM Sleep]
broader: sleep stages
type: Concept