CP PSYCHOLOGY

Altered States of Consciousness

SleepMrs. Bradley

Newark High School

Biological Rhythms• Biological Rhythms: periodic

physiological fluctuations built into human beings.

Ex: 28 day menstrual cycle, 24 hour alertness cycle, annual cycle, 90 minute sleep cycles.

Circadian Rhythm• Our 24 hour biological clock• The rhythm of activity and inactivity lasting approximately one day• Our body temperature and awareness changes throughout the day• It is best to take a test or study during your circadian peaks• Circadian rhythms are controlled by the hypothalmus part of the

brain.

But is the circadian 24-hour rhythm natural?

Do you stay up later on Friday night?

Even later on Saturday night?

Are you more tired than usual on Monday morning?

The circadian 24-hour rhythm is NOT natural…..

Studies have shown that our natural rhythm is actually 25 hours.

Studies that eliminate time cues (clocks, sunsets, etc) show that our natural internal rhythms run in 25 hour cycles.

Now you know why Monday mornings are so tough.

The body adjusts to time changes….

… through a process called “phase out.”

But adjusting to more than a one hour change is drastic to the body.

Jet Lag

East to west travel is easier than west to east.

The Stages of Sleep

• There are 4 stages of quiet sleep and 1 stage of active sleep

• Approx. 75% of sleep time is spent in stages 1 thru 4

• Approximately 25% of sleep time is spent dreaming

Sleep Study

• Electroencephalograph (EEG) and other devices are used to measure sleep activity

•EEG : Invented in 1929 by the German psychiatrist, Hans Berger.

•Electrodes are attached to the scalp to measure electrical impulses called brain waves.

•The invention of the EEG triggered many sleep studies.

The Discovery of REM

• Professor Nathaniel Kleitman and Eugene Aserinsky

•Rapid Eye Movement

•EOG – electro-oculogram: taped close to eyelids records vertical and horizontal movement

•EMG – electromyogram recorded chin and neck muscle movement which is almost completely relaxed during REM sleep.

The Discovery of REM

• Professor Nathaniel Kleitman and Eugene Aserinsky found that when subjects were awakened during REM sleep they almost always reported a dream.

•This seldom happened during Non-REM sleep.

•Discovery of REM led to more research in sleep disorders.

.

Measuring sleep activity

The discovery of REM -- rapid eye movement

The Stages of Sleep

• Researchers have discovered that we sleep in stages.

• These stages are defined according to brain wave patterns – measured by electroencephalograph (EEG).

• Brain waves (electrical activity) are cyclical. That is, they vary according to whether we are awake, relaxed, or sleeping.

• There are four different kinds of brain waves – beta, alpha, theta, and delta.

• Awake brain = beta waves (short and quick)• Begin to relax and get drowsy, the brain waves slow

and change to alpha waves (a little slower than beta)• After this relaxed state, sleep follows in five distinct

stages.

• Stage 1: Pulse slows, muscles relax, sensation of “drifting”, lasts about 10 minutes• Stage 2: Slower brain waves, eyes move slowly side-to-side, lasts about 30 minutes• Stage 3: Deeper sleep, large delta brain waves every few seconds, varies in length• Stage 4: State of oblivion, delta brain waves 50% of the time, varies in length

• REM (Rapid Eye Movement) Sleep: (dreaming) cycles in and out after stage 4

• Irregular breathing/pulse, adrenal and sex hormones increase, “ awake” brain waves

0 1 2 3 4 5 6 7

4

3

2

1

Sleepstages

Awake

Hours of sleep

REM SLEEP

Hours of sleep

Minutesof Stage 4 and REM

1 2 3 4 5 6 7 80

10

15

20

25

5

Decreasing Stage 4

Increasing REM

Sleep Stages• There are 5 identified stages of sleep.• It takes about 90-100 minutes to pass through the 5

stages.• The brain’s waves will change according to the sleep

stage you are in.• The first four stages and know as NREM sleep..• The fifth stage is called REM sleep.

Stage One

• This is experienced as falling to

sleep and is a transition stage

between wake and sleep. • It usually lasts between 1 and 5 minutes and occupies

approximately 2-5 % of a normal night of sleep. • eyes begin to roll slightly.• consists mostly of theta waves (high amplitude, low

frequency (slow)) • brief periods of alpha waves, similar to those present

while awake

Stage Two• This follows Stage 1 sleep and is the "baseline"

of sleep. • This stage is part of the 90 minute cycle and

occupies approximately 45-60% of sleep.

Stage Three & Four

• Stages three and four are "Delta" sleep or "slow wave" sleep and may last 15-30 minutes.

• It is called "slow wave" sleep because brain activity slows down dramatically from the "theta" rhythm of Stage 2 to a much slower rhythm called "delta" and the height or amplitude of the waves increases dramatically.

•People need less sleep as they get older• Babies need 16-18 hours of sleep daily• Teens 10-11 hours, adults 8 hours,• Seniors citizens need 5-6

How much sleep do you need?

Effects of Sleep Loss fatigue impaired concentration depressed immune

system greater vulnerability to

accidents

What if you didn’t sleep?• In 1964, a research

study was conducted under the supervision of a doctor a 17 year old boy stayed awake for almost 11 days straight.

• Result: he was extremely irritable, could not focus his eyes, had speech difficulties, memory lapses, accident prone and depressed immune system.

• Person would eventually die if they didn’t sleep.