4.3-4.4 Stages of Sleep and Sleep Disorders

Rapid Eye Movement (REM) Sleep

psychologically active sleep where dreaming occurs; voluntary muscles inhibited

non-REM (NREM) Sleep

spans lighter to deeper; restful sleep

electroencephalograph

machine that records the brain wave activity as a person sleeps

beta waves

small and fast waves when a person is awake

alpha waves

slightly larger and slower waves when a person relaxes and gets drowsy

theta waves

slow and large waves when a person sleeps

N1 - Light Sleep

theta wave activity increases, alpha wave activity fades; non REM; people will not believe that they are asleep if they are awakened; may experience hypnagogic images (hallucinations)

hypnic jerk

when someone drifts off to sleep and their knees, arms, and legs give a jerk

N2 - Sleep Spindles

body temperature continues to drop, heart rate slows, breathing becomes more shallow and irregular; EEG shows sleep spindles; people will be aware that they slept if they are woken up; theta wave activity predominant

sleep spindles

bursts of activity lasting 1-2 seconds during N2 sleep

N3 - Delta Waves

delta wave activity increases from 20 percent to 50 or more percent; deepest stage of sleep, known as slow wave sleep (SWS); people in deep sleep are very hard to awaken

delta waves

slowest and largest waves, appear in N3

R

stage with near waking temperatures; eyes move rapidly, heart beats faster, waves resemble beta waves; referred to as REM sleep; dreams are more vivid, detailed, longer, and more bizarre

sleep paralysis

muscles are paralyzed in REM sleep

REM rebound

being deprived of REM sleep increases REM the next night

nightmares

bad dreams, normally experienced during REM sleep

REM Behavior disorder

brain mechanisms that inhibit voluntary muscles fail

Night terrors

state of panic experienced in deep non-REM sleep

Insomnia

the inability to get sleep, stay asleep, or get good quality sleep

sleep apnea

person stops breathing for 10 seconds or more

narcolepsy

person slips suddenly into REM sleep during the day