Sleeping and Stuff

the biological clock; regular bodily rhythms (e.g. temperature and wakefulness) that occur on a 24-hour cycle

• Bright light in the morning tweaks circadian clock by activating light-sensitive retinal proteins
• Proteins control clock by triggering signals to the brain's SCN
• SCN causes brain's pineal gland to decrease melatonin production in the morning and increase it in the evening

• rapid eye movement sleep
• a recurring sleep stage during which vivid dreams commonly occur
• Muscles are relaxed, but other body systems are active

periodic, natural, reversible loss of consciousness, as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation

the relatively slow brain waves of a relaxed, awake state

• Slow Breathing
• Irregular Brain Waves
• May experience hallucinations and/or hypnagogic sensations

• characterized by periodic bursts of rapid, rhythmic brainwave activity
• Asleep, though can be awakened without much difficulty
• Sleeptalking can begin occuring

• Transitional Stage
• Brain starts to emit delta waves

the large, slow brain waves associated with deep sleep

• Deep Sleep Stage
• Delta waves are still emitted
• Near the end of stage 4, children may wet the bed or begin sleepwalking

• Sleep protects and helps us better suit our ecological niche
• Sleep helps us recuperate by restoring and repairing brain tissue
• Sleep is for rebuilding our fading memories of the day's experiences
• Sleep also feeds creative thinking
• Sleep may play a role in the growth process

recurring problems in falling or staying asleep

• a sleep disorder characterized by uncontrollable sleep attacks
• sufferer may lapse directly into REM sleep, often at inopportune times

a sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings

• a sleep disorder characterized by high arousal and an appearance of being terrified
• Unlike nightmares, night terrors occur during Stage 4 sleep