Dream

States of Consciousness Waking and Sleep Rhythms Consciousness ? our awareness of ourselves and our environment Biological Rhythms ? periodic physiological fluctuations Circadian Rhythm ? the biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle REM Sleep ? rapid eye movement sleep, a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active Alpha Waves ? the relatively slow brain waves of a relaxed, awake sleep Sleep ? periodic, natural, reversible loss of consciousness ? as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation