1. Consciousness Section 2
Sleep and Dreams
Consciousness
Section 2

2. Why do we sleep? Different theories…
It recharges our batteries – we recover from exhaustion and stress
It is a primitive form of hibernation (we are conserving energy)
It is adaptive (sleep kept humans safe at night when they would be more likely to be harmed by animals with better night vision

3. Sleep
State of altered consciousness with patterns of brain activity and inactivity
Consciousness – state of awareness, including feelings, sensations, ideas, and perceptions
Altered consciousness means that there are different levels of awareness.
Electroencephalograph – used to study the electrical activity of the brain during sleep

4. Stages of Sleep Physiological characteristics
Temperature decreases, heart rate drops, breathing is slow and even
Brain shows alpha waves which indicate an absence of concentration

5. Stages cont. Early stages Stage 1: ~10 minutes Stage 2: ~ 30 minutes
Pulse rate slows more and your muscles relax
Breathing is uneven
Brain waves are irregular (theta waves)
Stage 2: ~ 30 minutes
Eyes roll from side to side
Change in brain waves
Stage 3:
Deeper level
Brain waves are large in amplitude and not as frequent

6. Stages cont. Later stages Stage IV
Deepest sleep
Difficult to awaken; if awaken by a loud noise or sudden movement, you may be disoriented
Talking out, sleep-walking, bed-wetting occur during this stage (you do not remember these)
Must have deep sleep for physical and psychological functioning
REM sleep (active sleep) – rapid eye movement; ~15-45 minutes
Pulse rate and breathing are more irregular
Adrenal and sex hormones increase
Small muscles may twitch; large muscles are “paralyzed”
Brain waves are like those of someone who is fully awake
Most dreams happen
Cycle repeats approximately every 90 minutes

7. How much sleep do we need?
Newborns – 16 hours
7-12 years old – hours
Teens – 9
Adults – 8
Circadian rhythm – biological clock genetically programmed to regulate activity over 24 hour time period
Get hungry or sleepy at the same of day; go to the bathroom at the same time each day
Does not control sleep cycles

8. Sleep Disorders Insomnia Sleep apnea
Inability to get enough sleep at night in order to feel rested
Prolonged
Many causes:
Anxiety
Depression
Alcohol/drug use
Sleep apnea
Person has trouble breathing during sleep; breathing passages are blocked
Ends when low levels of oxygen or high levels of CO2 triggers breathing reflexes
Symptom – snoring that ends abruptly with a sudden movement of the body
Caused by a physical problem such as enlarged tonsils, infections in the throat or ears, or obesity

9. Sleep Disorders cont. Narcolepsy Nightmares and Night Terrors
Permanent and overwhelming feeling of sleepiness or fatigue
Person may fall asleep suddenly
May have hallucinations or unusual sleep patterns
Nightmares and Night Terrors
Nightmares occur during REM; person will awaken and remember the dream
Night terrors – occur during stage IV; last 5-20 minutes; may involve screaming, sweating, confusion, and a rapid heart rate; person will not remember the night terror
Sleepwalking and Sleep talking
Sleepwalking – person is partially but not completely awake; person will walk or do other things without any recollection of doing so
Occurs mostly with children
Neither dangerous or necessary to awaken sleepwalkers
Talking – words or phrases
Can occur during REM or NonREM
Usually do not remember it

10. Dreams Dreams at first are a result of the days activity
As sleep progresses, dreams are longer, more vivid, and dramatic
The last is usually the longest and the one a person remembers
Content
Usually dull; however we remember the ones that are more interesting
Usually occur in a common setting (work, home, school)
A large percentage of emotions are negative – anxiety, anger, etc.
Dream interpretation
Sigmund Freud – dreams contain clues to thoughts the person is afraid to acknowledge; believed they contained hidden messages
Some cultures believe that during dreams people can interact with people who have died
Some think that dreams allow a person to review and address some of the problems of the day
Daydreams
Require a low level of awareness
Involve fantasizing or idle thinking
May allow us to control our creativity and our emotions