rapid eye movement A phenomenon observed in sleeping people. REM has been calculated to take up to 20% of a normal night's sleep and has been associated with the time spent dreaming. The sleeper passes in and out of REM sleep and, although it is possible to make do with very little sleep, he or she suffers if deprived of REM sleep. Related category • ANATOMY AND PHYSIOLOGY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |