Consciousness & Sleep

Today’s Goal: Define the levels of consciousness and

the stages of the sleep cycle.

Consciousness• Awareness of ourselves &

environment• Preconscious • Nonconscious• Unconscious • Dual processing

Circadian Rhythm

• Biological clock – regular bodily rhythms of 24-hour cycle

• Suprachiasmatic nucleus (SCN) – regulates gland production of melatonin

Sleep Cycle/Stages• EEG – brain wave activity• Stages 1-4 = NREM sleep• REM sleep

• Electrooculograms – eye movement• Electromyograms – muscle tension

• Today’s Goal: Define the levels of consciousness and the stages of the sleep cycle.

NREM/REM Sleep• NREM (non-rapid-eye-movement)– 75% of sleep– Restores the body

• REM (rapid-eye-movement– 25% of sleep– Restores brain– Vivid dreams– Body immobile

• Awake & alert – Beta waves– Faster, irregular waves – 15-45 peaks per second

• Awake but relaxed – Alpha waves– Smooth, regular waves– 10 peaks per sec.

NREM Stage 1• Theta waves• ~10 min.• Transition from wakefulness

to sleep• Hypnagogic state – brief

dreamlike experience• Hypnic jerks (body shutting

down)

NREM Stage 2• Theta waves• Sleep spindles – brief bursts in wave

frequency• K Complexes – brief bursts in wave

amplitude

Stages 3 & 4• Delta waves~30-40 min. of cycle• Blood pressure drops• Slowed breathing• Tissue growth, repairs• Growth hormone

REM Sleep• Paradoxical sleep• Brain is active but

body is immobile• Vivid dreams• Cortisol drops• Helps immune

system

Sleep Cycle

Sleep Cycle