SLEEP TIME!!! (ZZZ)No demonstrations, please!SLEEP- The minimal level of

awareness and processing that takes place.

A passive state of consciousness.

What makes sleep?

1. Stereotypic posture2. Little movement3. Reduced response4. Reversibility

Our CyclesSleep-Wake Cycle- just one of the

circadian rhythmslight and dark cues control itSCN (suprachiasmatic nucleus)Hypothalamus-> pituitary (master

gland)pineal gland -- Melatonin25 HOURS!!!

What controls your sleep-wake cycle?

Circadian Rhythms: Life CyclesProblems with

sleep-wake cycle: Seasonal

affective disorder

Jet lag Shift work Sleep disorders

Problems with Rhythms

Jet LagEast to West is best (phase delay

easier than phase advance)the ‘night shift’days->evenings->nights, 2 wks or

more is better

Measuring Sleep

Sleep cycle- the movement between stages and states of sleep

Stages- the PHYSICAL changes that occur during the sleep cycle

STATES vs. STAGES

State- Our MENTAL abilities.

The state is determined by the stage!!!

How do we measure?

PolysomnographEEG- electroencephalographmeasures electrical brain

activity on the scalpmeasures “BRAIN WAVES”

SleepWe descend

through NREM Stages I to 4 and then ascend through them to rapid eye movement (REM) sleep.

Stages of SleepStage 1NREM

transition between wakefulness and sleep (beta, alpha) theta

Stage 2NREM~50% of sleep cyclesleep spindles and K complexes

Stages of SleepStage 3NREM

Brain waves become slower (delta waves)

Stage 4NREMDeepest stage of sleep (50%+ delta waves)

least responsive to outside stimuli

A.k.a slow-wave sleep

How do we measure?

EOG- electroocculographmeasures eye movementREM vs Non-REM sleep

The Sleep Stages/States

NREM- non-rapid eye movement (4 stages)

REM- rapid eye movement

How do we measure?

EMG- electromyographmeasures muscle tension via

electrical impulsesREM vs Non-REM

Rapid eye movementAlpha, beta brainwavesIncreased heart rate,

blood pressure, respiration, circulationErections in males

1REM Sleep

REM SleepUsually accompanied by

dreams (dream state)body is “paralyzed”-

paradoxical sleepMyoclonic jerk

The Study of Sleepaverage adult repeats this cycle four to six times

each night.Sleep decreases from about 16 hours at birth to

about 7 to 8 hours in young adulthood, with little change thereafter.

The Sleep Cycle

Go deepest @ beginningmore REM later on3-6 a night80 minutes NREM10 minutes REMless as older

Why do we sleep??

GOOD QUESTION!!!Thousands of articles/yearCircadian Rhythms- natural

biological process that occur daily

your biological clock

The Main Theories

Repair/ Restoration - enable body to recover from day’s exertions.

Energy Conservation (~120 kc)Cool off Brain (temp?)

The Main Theories

Boost Immune system sleep deprivation boosts

immunity in some studies

Stay out of harm’s way by being unaware?

The Main Theories

Improve memory reprocess day’s events

Purge memory create more RAM space.

Neural development

Deprivation Studies

Randy Gardner- 264 hours no sleep, 14 hours first night, 8 next!

Avg. Americans get 2 hours LESS sleep than needed

(Sleep DEBT)

Deprivation Studies

depression, irritability in someREM rebound- make up

for lost REMs the first night

Deprivation Studies

Microsleeps – short periods of sleep that intrude on wakefulness – your brain NEEDS sleep!

Sleep Disorders

sleep deprivation/ disorders cost Americans $100 billion/ year in illness, injuries, death and property damage.

SLEEP DISORDERS

SLEEP DISORDERS

Insomnia- inability to fall (onset) or stay asleep (transient or chronic)

Rx (benzodiazepenes), change in lifestyle, meditation

PARASOMNIAS

Sleep Walking/talking/texting/

eating 3-4NREM “Myoclonic jerk”rest, relaxation, Rx, hypnosis

PARASOMNIAS

Night Terrors Stage 4NREM: muscles ARE NOT paralyzed

“awaken” screaming in terrormostly childrennot dreamingPanic attack!

PARASOMNIAS

REM sleep behavior disordermostly older men >50violent outbursts. Muscles not paralyzed in REMRx: Muscle relaxers

PARASOMNIAS

SIDS- sudden infant death syndrome

1 month to 1 year oldmedulla defectssuffocation?Positioning- NOT on belly

PARASOMNIAS

Restless Legs Syndromelegs twitch at night, can’t

sleepGenetics?iron, exercise, diet, Rx

HYPERSOMNIAS

Sleep Apnea- stop breathingup to 5 minutes!Overweight and snoringchronic health problemsmachine helps- CPAP

HYPERSOMNIAS

Narcolepsy- fall asleep unexpectedly

excessive sudden sleepinessnervous system disorder with

REM sleep while awake!Rx: stimulants