NREM and REM sleep

NREM sleep

3 stages

reduction in psych. activity

lower frequency and high amplitude

respiration and heart rate slows + blood pressure drop

bodily functions in NREM

recovers

repairs tissues

removes waste materials

replenishes neurotransmitters

NREM stage 1

5 minutes long

wakefulness —> sleep (very light sleep)

LOW AROUSAL THRESHOLD (woken up easily)
alpha —> theta

NREM stage 1 physiological

heartrate, breathing, body temp + muscle tension down down

muscles relax + hypnic jerks (involuntary muscle twitches that make us jolt)

vivid images and flashes

NREM stage 2

10-25 minutes (half of our total sleep)

higher arousal threshold but still easy to be woken

theta waves

NREM stage 2 physiological

eyes stop rolling

more relaxed muscles

breathing and heartrate continue decreasing

• sleep spindles + k complexes

sleep spindles

short bursts of rapid brainwave activity

k complexes

single sudden high amplitude waves about once a minute

NREM stage 3

difficult to be woken up

groggy and disoriented if woken up (sleep inertia)

theta —> delta

deepest sleep (no conscious awareness) + 30 minutes

NREM stage 3 physiological

no eye movement

no muscle activity

heart rate and breathing at slowest + temp at lowest

REM SLEEP

higher arousal (beta like waves) but not awake

consolidates memories + forms new neuron connections

brain is active + young people have more REM than old

characteristics of REM sleep

increase + fluctuations of heart rate breathing temp and blood pressure

no muscle tension (muscle atona/cataplexy)

paradoxical sleep (body is calm on outside but brain and body are highly active on inside)

entered after 90 minutes of falling asleep

SLEEP CYCLE WORKING

stage 1 —> stage 2 —> stage 3 —> stage 2 —> REM —> stage 2 —> stage 3
90 minutes in 4-5 cycles a night