Psych - Sleep

Circadian Rhythm

a cycle of biological functioning that regulates sleep cycles

Pineal Gland / eye photoreceptors

how is the circadian rhythm regulated?

Retina

Process light and determines the amount of melatonin produced

Melatonin

chemical that induces sleep

Sleep

periodic, natural, reversible loss of consciousness

EEG

technology which helps use see sleep cycles

Alpha waves

frequency when awake

Stage 1 (initial sleep stage)

transition between wakefulness and sleep, lasts 5-10 minutes

Theta Waves

Slower than alpha waves used to calm down in sleep stage 1

Hyponagogic Hallucinations

in sleep stage 1, falling sensation/ rocking/ tetris effect (seeing shapes)

Stage 2 (middle sleep stage)

heart rate drops, brain frequency accelerates, lasts 20 minutes

Sleep Spindles

a burst of brain activity when the brain is working hard to stop thinking/ fall asleep

Sigma Waves

frequency of sleep stage 2 - shows sleep spindles

K-complexes

irregular brain wave when cortex is stimulated but no reaction occurs (ex. touching a person who does not respond because they are asleep)

Stage 3 (deep sleep transition)

begins to produce delta waves and only lasts for a few minutes

Delta waves

large slow frequency of brain activity to induce deep sleep

Stage 4 (full deep sleep)

when the body repairs itself, lasts 30 minutes, many delta waves (when sleepwalking/ bed wetting/ night terrors occur - hard to wake!)

Nigh Terrors

when you wake up screaming without reason and hard to remember why/ next morning (because not story-like) - more common in children - ppl grow out of it or need stress reductions

REM Sleep

Rapid Eye Movement - when the brain is most active / dreams (process emotions, stressors, and memories)

Paradoxical Sleep

the motor cortex is active but movement messages are blocked so one cannot actually act out what they are dreaming - eyes dart around beneath eyelids

Hallucinatory Dreams

vivid and story-like

4-7 cycles

how many cycles of sleep stages do you need per night?

Growth Hormone

secreted in sleep stage 4

typically less sleep

older people

typically more sleep

younger people (still developing)

Sleep Deprivation

When you don’t get enough sleep (causes irritability, reduced concentration, and decreased immune system effectiveness)

Insomnia

Trouble falling/ staying asleep - 30% have acute and 10% have chronic - healed by natural remedies like exercise and medications

Sleep Apnea

Stop of breathing during sleep due to a lack of oxygen - 15% mostly overweight men - healed with weight loss, medications, and CPAP sleep mask

Narcolepsy

Sudden uncontrollable sleepiness due to reticular formation malfunction or under-supply of orexin (alertness) - healed with medications and rare

Consistent sleep

better to have consistent or catch up on sleep?