1. Bell Work
What effect does sleep have on behavior?

2. Rhythms

3. Biological Rhythms Annual cycles: seasonal variations
Seasonal depression
28 Day Cycle: menstruation
24 hour cycle: circadian rhythm
90 minute cycle: sleep cycle

4. Circadian Rhythms Internal 24 hour clock
Body changes throughout the day
Hormones, temperature, etc.
Think jet lag…

5. Sleep

6. The Sleep Cycle REM (Rapid Eye Movement) NREM (Non-REM) – 4 stages
Takes about 90 min to get through all cycles of sleep…
Brain waves change between stages

7. Stages of NREM

9. Stage 1 Transition between wake and sleep.
Lasts between 1 and 5 minutes and occupies approximately 2-5 % of a normal night of sleep.
consists mostly of theta waves
brief periods of alpha waves

10. Stage 2 Muscle activity and awareness decrease Body temperature cools
May perceive falling
Theta waves w/o alpha
Most time is spent here (45-60%)

11. Stage 3 First stage of deep sleep Less aware of stimuli
Time in stage 3 decreases throughout the night
Delta waves
Temperature, breathing, heart rate at lowest
Most common NREM stage for dreams…

12. Stage 4
More frequent delta waves than stage 3
Deepest sleep…

13. Go back to 3, then 2, then 1.

14. REM Sleep

15. REM This is a very active stage of sleep.
Composes % of a normal nights sleep.
Breathing, heart rate and brain wave activity quicken.
Similar to being awake
Vivid Dreams can occur.
Most dreams occur here
From REM, you go back to Stage 2
Body is essentially paralyzed during REM.

16. Sleep Disorders

17. Insomnia Persistent problems falling asleep
Effects 10% of the population
Primary versus Secondary Insomnia
Primary – cannot be attributed to a medical cause
Secondary – symptom of medical disorder

18. Narcolepsy
Suffer from sleeplessness and may fall asleep at unpredictable or inappropriate times.
Directly into REM sleep
Less than .001 % of population.

19. Sleep Apnea A person stops breathing during their sleep.
Wake up momentarily, gasps for air, then falls back asleep.
Very common, especially in heavy males.
Can be fatal.

20. Night Terrors Wake up screaming and have no idea why. Not a nightmare.
Most common in children (boys) between ages 2-8.

21. Sleep Walking
Most often occurs during the first few hours of sleeping and in stage 4 (deep sleep).
May look/act like they’re awake
If you have had night terrors, you are more likely to sleep walk when older.

22. Wrap Up
What stage of sleep