1. States of Consciousness

2. Consciousness  The awareness we have of ourselves and our environment

3.  Different states of consciousness are associated with different patterns of brain waves as measured using an electroencephalograph (EEG)

5. Sleep

6. Biological Rhythms  Sleep is affected by biological rhythms or periodic physiological changes  Biological rhythms are regular, periodic changes in a body’s functioning

7. Circadian Rhythms  Biological cycles that occur about every 24- hours

8. Infradian Rhythms  Biological cycles that take longer than 24- hours

9. Ultradian Rhythms  Biological cycles that occur more than once a day

10.  Biological rhythms usually synchronize with environmental events & many continue without cues from the environment

11. Biological Clocks  Endogenous rhythms exist because the body has biological clocks that keep time  The suprachiasmatic nucleus (SNC)

12. Jet Lag  People experience jet lag when the event sin the environment are out of sync with their biological clocks

13. The Function of Sleep  We don’t really know why people sleep.  Several theories exists that attempt to answer the why’s of sleep.

14. Sleep Research  Researchers study sleep by monitoring subjects who spend the night in labs, and they use various instruments for different purposes

15.  Electroencephalographs (EEG): record brain waves  Electromyographs (EMG): record muscle activity  Electrooculographs (EOG): record eye movements  Electrocardiographs (EKG): record the activity of the heart

16. Sleep Stages  During one night’s sleep, people pass through several cycles of sleep

17. Stages 1-4  When people are relaxed and ready to fall asleep, their EEG will show mostly alpha waves  When people fall asleep, they enter into stage 1 sleep, which lasts just a few minutes  In stage 1, the EEG shows mostly theta waves

18.  Stage 2 lasts about 20 minutes and is characterized by short bursts of brain waves called sleep spindles

19.  In stages 3 and 4, which together last about 30 minutes, the EEG displays mostly delta waves

20. REM Sleep  At the end of stage 4, people go back through the stages in reverse, from 4 to 3 to 2 to 1  When they reach stage 1, instead of waking up, people go into REM, or rapid eye movement, sleep –A single cycle might look like this: 1 2 3 4 3 2 1 REM 1 2 3 4 3 2 1 REM

21.  During REM sleep, pulse rate and breathing become irregular, eyes move rapidly under closed lids, and muscles remain very relaxed  Although dreaming happens in other sleep stages as well, dreams are most vivid and frequent during REM sleep

22.  People typically go through about 4 sleep cycles during one night of sleep  The REM stage of sleep gets longer and longer as the night passes, while stage 3 and 4 sleep gets shorter and shorter  About 40-60 minutes in REM each night

23. Sleep Deprivation  Different people need different amounts of sleep  Insufficient sleep can have negative effects  REM rebound

24. Aging and Sleep  Sleep patterns change as we age  Newborn babies spend about two-thirds of their time in sleep  As they age, they tend to sleep less  Amount of time spent in REM also changes

25.  From age 1 to the mid-20s, approximately 25% of total sleep is spent in SWS  After mid-20s, daily sleep pattern becomes stable from now until about age 60, except for SWS which drops dramatically after age 30

26.  The younger a person is, the more sleep they require

27. Sleep Disorders  Everyone has occasional difficulty sleeping  These disorders are chronic in nature

28.  Insomnia –A chronic problem with falling and staying asleep –Basic patterns of insomnia

29.  Narcolepsy –A tendency to fall asleep periodically during the day –Can be dangerous –Cause of narcolepsy is unknown

30.  Sleep apnea –A condition in which a person stops breathing many times during a night’s sleep –Can be a very dangerous condition

31.  Night Terrors –Abrupt awakenings from non-REM sleep accompanied by intense autonomic arousal and feelings of panic –Most common in children ages 2-6, although it sometimes occurs in adults –Tends to run in families –Why is still a mystery –Not indicative of psychological problems

32.  Sleep Starts –Most people have experience the common motor sleep start - a sudden, often violent, jerk of the entire body that occurs upon falling asleep. –Other forms of sleep starts also occur just as sleep begins such as, but these occurrences are harmless.

33.  Sleep Talking (somniloquy) –Sleep talking is a normal phenomenon and is of no medical or psychological importance.

34.  Sleepwalking (somnambulism) –Estimated 10% at least one episode –Not acting out a dream –Cause is unknown, may be affected by stress –Typically occurs during SWS –Most common among children (4-12) –Typically not serious, but can be “scary”