Revised version of the activation-synthesis explanation of dreams in which information that is accessed during waking hours can have an influence on the synthesis of dreams.

• activation-information-mode model AIM hypothesis (AIM)

• rapid eye movement (REM) sleep

• adaptive theory

• active-informative-motion hypothesis (AIM)

Sleep disorder in which a person falls immediately into REM sleep during the day without warning.

• circadian rhythm

• insomnia

• narcolepsy

• altered states of consciousness

The inability to get to sleep, stay asleep, or get a good quality of sleep.

• narcolepsy

• insomnia

• restorative theory

• rapid eye movement (REM) sleep

Long, slow brain waves that indicate the deepest stage of sleep.

• delta waves

• alpha waves

• ultraviolet waves

• infrared waves

Brain waves that indicate a state of relaxation or light sleep (drowsing).

• infrared waves

• ultraviolet waves

• delta waves

• alpha waves

Any of the stages of sleep that do not include REM.

• non-REM (NREM) sleep

• rapid eye movement (REM) sleep

• stop-REM (SREM) sleep

• rapid even movement (REM)

Theory of sleep proposing that sleep is necessary to the physical health of the body and serves to replenish chemicals and repair cellular damage.

• circadian theory

• adaptive theory

• restorative theory

• consciousness theory

Theory of sleep proposing that animals and humans evolved sleep patterns to avoid predators by sleeping when predators are most active.

• consciousness theory

• adaptive theory

• circadian theory

• restorative theory

A cycle of bodily rhythm that occurs over a 24-hour period.

• circadian rhythm

• internal clock

• time rhythm

• restorative theory

State in which there is a shift in the quality or pattern of mental activity as compared to waking consciousness.

• consciousness

• altered rhythm

• altered states of consciousness

• circadian rhythm