CP PSYCHOLOGY Altered States of Consciousness Sleep Mrs. 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

Sleep stages Awake Hours of sleep REM SLEEP

Hours of sleep Minutes of Stage 4 and REM Decreasing Stage 4 Increasing REM

Sleep Stages There are 5 identified stages of sleep. It takes about 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 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 hours of sleep daily Teens 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.