the relatively slow brain waves of a relaxed, awake state
the daily biological rhythms that occur in a 24-hour period
myoclonic (hypnic) jerk
involuntary muscle spasms of the whole body that jolts a person completely awake.
the tendency for REM sleep to increase following REM sleep deprivation
according to Freud, the remembered story line of a dream
a sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings
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.
the large, slow brain waves associated with deep sleep
recurring problems in falling or staying asleep
a sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times
a sleep disorder characterized by high arousal and an appearance of being terrified; unlike nightmares, night terrors occur during Stage 4 sleep, within two or three hours of falling asleep, and are seldom remembered
according to Freud, the underlying meaning of a dream
a sequence of images, emotions, and thoughts passing through a sleeping person's mind
short bursts of brain waves detected in stage 2 sleep
brain waves seen during alert wakefulness
state of being unable to move just after falling asleep or right before waking up.
activation synthesis theory
the theory that dreams result from the brain's attempt to make sense of random neural signals that fire during sleep