1. Chapter 5: Variations in Consciousness

2. The Nature of Consciousness
What is consciousness?
Your awareness of external events
your awareness of internal sensations
your awareness of yourself as a unique being having experiences
your awareness of your thoughts about these experiences
The critical element in consciousness is awareness!

3. Variations in Consciousness
Levels of awareness
Consciousness is not all-or-none
Awake
Sleep
Anesthesia
Coma
Persistent Vegetative State
Death

4. Definitions of Death
As little as 50 years ago, people were considered “dead” when their heartbeat & breathing stopped.
Brain Death
total unawareness of externally applied stimuli
no movements or breathing during a period of at least one hour
no reflexes
flat EEG (no brain waves)

5. The Electroencephalograph: A Physiological Index of Consciousness
EEG – monitoring of brain electrical activity
Brain-waves
Amplitude (height)
Frequency (cycles per second)
Beta (13-24 cps)
Alpha (8-12 cps)
Theta (4-7 cps)
Delta (<4 cps)

7. Biological Rhythms and Sleep
Circadian Rhythms – 24 hr biological cycles
Regulation of sleep/other body functions
Physiological pathway of the biological clock:
Light levels  retina  suprachiasmatic nucleus of hypothalamus  pineal gland  secretion of melatonin
Melatonin and circadian rhythms

8. Sleep/Waking Research
Instruments:
Electroencephalograph – brain electrical activity
Electromyograph – muscle activity
Electrooculograph – eye movements
Other bodily functions also observed

9. Sleep Stages: Cycling Through Sleep
Stage 1: brief, transitional (1-7 minutes)
alpha  theta
hypnic jerks
Stage 2: sleep spindles (10-25 minutes)
Stages 3 & 4: slow-wave sleep (30 minutes)
Stage 5: REM, EEG similar to awake, vivid dreaming (first a few minutes, then longer)
Developmental differences in REM sleep

10. Fig. 5-6, p. 182

11. Figure 5.5 An overview of the cycle of sleep

12. The Neural Bases of Sleep
Brain Structures:
Ascending reticular activating system
Pons, medulla, thalamus, hypothalamus, limbic system
Neurotransmitters:
Acetylcholine and serotonin
Also norepinephrine, dopamine, and GABA

13. Why Do We Sleep? Hypothesis 1: Hypothesis 2: Hypothesis 3:
Sleep evolved to conserve organisms’ energy
Hypothesis 2:
Immobilization during sleep is adaptive because it reduces danger
Hypothesis 3:
Sleep helps animals to restore energy and other bodily resources

14. Sleep Deprivation Complete deprivation
3 or 4 days max
Partial deprivation or sleep restriction
impaired attention, reaction time, coordination, and decision making
accidents: Chernobyl, Exxon Valdez
Selective deprivation
REM and slow-wave sleep: rebound effect

15. Figure 5.9 Effect of sleep deprivation on cognitive performance

16. Sleep Problems Insomnia – difficulty falling or staying asleep
Narcolepsy – falling asleep uncontrollably
Sleep Apnea – reflexive gasping for air that awakens
Nightmares – anxiety arousing dreams - REM
Night Terrors – intense arousal and panic - NREM
Somnambulism – sleepwalking

17. Types of Insomnia Three “flavors” of insomnia
Difficulty falling asleep
No problem falling asleep but difficulty staying asleep (many awakenings)
Waking up too early
Three basic types of Insomnia
Transient insomnia - lasting for a few nights
Short-term insomnia - two or three weeks of poor sleep
Chronic insomnia - poor sleep that last three weeks or longer

18. Figure 5.12 Sleep problems and the cycle of sleep

19. Dreams and Dreaming: Content and Significance
Dreams – mental experiences during sleep
Content usually familiar
Common themes
Waking life spillover – day residue
Western vs. Non-Western interpretations

20. Figure 5.14 Three theories of dreaming

21. Hypnosis: Altered State of Consciousness or Role Playing?
Hypnosis = a systematic procedure that increases suggestibility
Theories of hypnosis
Role Playing (Barber & Spanos)
people act out the “role” of hypnotized subjects and do what they think hypnotized people should do
Altered State of Consciousness (Hilgard)
people dissociate by splitting awareness into two separate simultaneous streams of awareness
Hypnotic susceptibility: individual differences
Effects produced through hypnosis:
Anesthesia
Sensory distortions and hallucinations
Disinhibition
Posthypnotic suggestions and amnesia

22. Meditation
Meditation = practices that train attention to heighten awareness and bring mental processes under greater voluntary control
Yoga, Zen, transcendental meditation (TM)
Potential physiological benefits
Similar to effective relaxation procedures

23. Psychoactive drugs Narcotics (opiates) – pain relieving
Sedatives – sleep inducing
Stimulants – increase CNS activity
Hallucinogens – distort sensory and perceptual experience
Cannabis – produce mild, relaxed euphoria
Alcohol – produces relaxed euphoria, decreases in inhibitions
MDMA – produces a warm, friendly euphoria

24. Table 5.3 Psychoactive Drugs: Tolerance, Dependence, Potential for Fatal Overdose, and Health Risks