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Understanding Consciousness: Awareness, Sleep, and Altered States

This chapter delves into the nature of consciousness, exploring your awareness of external events, internal sensations, and self-identity. It discusses various levels of consciousness, including states of wakefulness, sleep, and different conditions like coma and brain death. The role of brain activity monitored by EEG is highlighted, alongside biological rhythms such as circadian cycles. It examines sleep stages, sleep disorders, dream significance, and techniques like hypnosis and meditation as methods to alter consciousness. The impacts of psychoactive substances are also explored.

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Understanding Consciousness: Awareness, Sleep, and Altered States

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  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)

  6. 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

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

  8. 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

  9. Fig. 5-6, p. 182

  10. Figure 5.5 An overview of the cycle of sleep

  11. 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

  12. Why Do We Sleep? • Hypothesis 1: • 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

  13. 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

  14. Figure 5.9 Effect of sleep deprivation on cognitive performance

  15. 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

  16. 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

  17. Figure 5.12 Sleep problems and the cycle of sleep

  18. 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

  19. Figure 5.14 Three theories of dreaming

  20. 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

  21. 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

  22. 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

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

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