circadian rhythm
the biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle.
NREM sleep
a recurring sleep state during which rapid eye movements do not occur and dreaming does not occur
REM sleep
a recurring sleep state during which dreaming occurs
Delta Sleep
deepest sleep cycle
Paradoxical Sleep
a recurring sleep state during which dreaming occurs
Jet Lag
fatigue and sleep disturbance resulting from disruption of the body's normal circadian rhythm as a result of jet travel
Sleep Deprivation
any significant loss of sleep, resulting in problems in concentration and irritability
Sleep Apnea
a sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings
Narcolepsy
a sleep disorder characterized by sudden and uncontrollable episodes of deep sleep
Insomnia
an inability to sleep
Sleep Walking
walking during non-REM sleep
Nightmare
a terrifying or deeply upsetting dream
Latent Dream Content
According to psychoanalyst Sigmund Freud, the latent content of a dream is the hidden psychological meaning of the dream. Freud believed that the content of dreams is related to wish fulfillment and suggested that dreams have two types of content: manifes
Manifest Dream Content
The narrative story of a dream that sometimes provides allusions to the latent content (deeper meaning of a dream). Freud believed that your unconscious uses distortions in the manifest dream content like condensation and substitution to reveal clues to o
Lucid Dreaming
awareness that a dream is a dream while it is happening
Dream
a series of mental images and emotions occurring during sleep