Normal stage of sleep, characterized by random, rapid movement of the eyes. Criteria for determining REM sleep include low muscle tone and rapid eye movement. Also known as: activated sleep. See also: dream state.

REM SLEEP: "REM sleep accounts for about one-quarter of total sleep time."
Cite this page: N., Pam M.S., "REM SLEEP," in, April 28, 2013, (accessed May 11, 2021).