1. Sleep

2. Variations in Consciousness
Consciousness – Awareness of internal and external stimuli
“personal awareness”
Example

3. Variation in levels of awareness
Consciousness is not all or none
We still have some level of awareness during sleep and even while under anesthesia during surgery
Examples

4. Studying states of consciousness
Electroencephalograph (EEG) –a device that monitors electrical activity of the brain over time
Records electrodes attached to surface of scalp
This shows the rhythm of activity of brain (brain waves)

6. Biological Rhythms and Sleep
Circadian Rhythm – 24 hour biological cycles found in humans and other species
Influential in sleep regulation
These rhythms prime us to fall asleep easily at a certain point in day
“ideal” time

7. Ignoring Rhythms (Ideal Sleep)
What happens when we ignore our biological clocks and sleep at an unusual time?
Quality suffers
Tired, sluggish, irritable for days, lower cognitive performance
Equates with “jet lag”
This is especially problematic for workers constantly switching and working odd shifts.
What some studies show

8. Realigning Circadian Rhythms
Researchers have studied methods to get over this feeling of “jet lag”
Options
Certain type of drug (melanonin)
Carefully timed exposure to bright light
Carefully plan rotation schedules at work
Problem with options

9. The Sleep and Waking Cycle
Former thoughts about sleep…
Now realize that much physical and mental activity happens during sleep
How did we form this understanding?
Sleep Laboratories
Volunteer patients spend night
What happens in these labs?
Video clip

10. Sleep Stages Sleep onset is gradual
Once we fall asleep, humans progress through different stages
Stages 1-4- Commonly referred to as non- REM sleep
Respiration, heart rate, and body temperature decrease with each stage
Brain waves increase as we progress

11. REM Sleep This is the fifth and final sleep stage
REM= Rapid eye movements
How are these measured?
How were they discovered?
REM is the deepest form of sleep
Rapid eye movements
High frequency brain waves
Dreaming
Sleep cycle (Stages 1-5) repeat during night

12. Cultural Variations in sleep
Cultures mostly similar in terms of sleep experience and activity
Differ on other matters
Co-sleeping- children and parents sleeping together
More accepted in other cultures
Examples
Napping
Some societies close shops and activities during day to permit naps for an hour or two
examples

13. Sleep Deprivation
Research has focused on sleep restriction – partial sleep deprivation
Seems that much of the U.S. are chronic sufferers
Effects our attention, reaction time, decision making
Night time workers fall asleep on job
Numerous accidents are result of sleep deprivation
Examples

14. Selective Deprivation
Many lab studies awake participants whenever they begin to go into REM
Selectively deprived of REM
As nights go by, need to awaken more and more
REM begins to happen more spontaneously in these patients now
Following deprivation:
Rebound Effect- patients spend extra time in REM sleep for one to three nights

15. Sleep Problems Insomnia- chronic problems getting adequate sleep
15-17% of adults suffer from severe insomnia
Narcolepsy- marked by sudden, irresistible onsets of sleep during normal waking periods.
Awake directly to REM sleep
Very rare
Sleep Apnea- frequent, reflexive gasping for air that awakens person and disrupts sleep
Person literally stops breathing for 10 seconds
Clips (if time)