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Chapter 5

Chapter 5. Variations in Consciousness. Consciousness: Personal Awareness. Awareness of Internal and External Stimuli Levels of awareness James – stream of consciousness Freud – unconscious Sleep/dreaming research. The Electroencephalograph: A Physiological Index of Consciousness.

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Chapter 5

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  1. Chapter 5 Variations in Consciousness

  2. Consciousness: Personal Awareness • Awareness of Internal and External Stimuli • Levels of awareness • James – stream of consciousness • Freud – unconscious • Sleep/dreaming research

  3. 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) - alert • Alpha (8-12 cps) - relaxing • Theta (4-7 cps) - sleep • Delta (<4 cps) – deep sleep • Because All Toros Dream

  4. Biological Rhythms and Sleep • Circadian Rhythms – 24 hr biological cycles • Regulation of sleep/other body functions • Free-running (without external stimuli) it will be closer to 25 hours • Physiological pathway of the biological clock: • Light levels -> retina -> suprachiasmatic nucleus of hypothalamus -> pineal gland -> secretion of melatonin • Melatonin and circadian rhythms • Melatonin used to help with jetlag

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

  6. Sleep Stages: Cycling Through Sleep • Stage 1: brief, transitional (1-7 minutes) • alpha -> theta • Hypnic (myoclonic) 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 (initially a few minutes, progressively longer as cycle through the stages) • Developmental differences in REM sleep • Infants spend much more time in REM than do adults.

  7. Figure 5.5 An overview of the cycle of sleep

  8. 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

  9. 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

  10. 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

  11. Sleep Problems • A majority of adults in the U.S. (62%) experienced a sleep problem a few nights per week or more during the past year. (Sleep Ominbus Survey 2000) • Insomnia – difficulty falling or staying asleep - (58%) – F 5.10 • Narcolepsy – falling asleep uncontrollably • Sleep Apnea – reflexive gasping for air that awakens - (10%) – current estimates: 21 million in US and 470 million in the world • Nightmares – anxiety arousing dreams - REM • Night Terrors – intense arousal and panic - NREM • Somnambulism – sleepwalking

  12. Dreams and Dreaming: Content and Significance • Dreams – mental experiences during sleep • Content usually familiar • Common themes • hallucinatory imagery • discontinuities • delusional acceptance of the content • difficulties remembering • Waking life spillover – day residue • Western vs. Non-Western interpretations

  13. DREAMS • Hobson & McCarley – activation – synthesis hypothesis • Sigmund Freud--The Interpretation of Dreams (1900) • wish fulfillment • discharge otherwise unacceptable feelings • Manifest Content • remembered story line • Latent Content • underlying meaning

  14. Hypnosis: Altered State of Consciousness or Role Playing? • Hypnosis = a systematic procedure that increases suggestibility • Hypnotic susceptibility: individual differences • Effects produced through hypnosis: • Anesthesia • Sensory distortions and hallucinations • Disinhibition • Posthypnotic suggestions and amnesia

  15. HYPNOSIS • Orne & Evans (1965) • control group instructed to “pretend” • unhypnotized subjects performed the same acts as the hypnotized ones • Posthypnotic Suggestion • suggestion to be carried out after the subject is no longer hypnotized • used by some clinicians to control undesired symptoms and behaviors

  16. HYPNOSIS • Dissociation • a split in consciousness • allows some thoughts and behaviors to occur simultaneously with others • Hidden Observer • Hilgard’s term describing a hypnotized subject’s awareness of experiences, such as pain, that go unreported during hypnosis

  17. 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

  18. Principal Abused Drugs and Their Effects • 6 categories of 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 (ecstasy) – produces a warm, friendly euphoria

  19. Big effect Response to first exposure Drug effect After repeated exposure, more drug is needed to produce same effect Little effect Large Small Drug dose DRUGS • Tolerance • diminishing effect with regular use • Withdrawal • discomfort and distress that follow discontinued use

  20. DRUGS • Depressants (Sedatives) • drugs that reduce neural activity • slow body functions • alcohol, barbiturates, opiates • Stimulants • drugs that excite neural activity • speed up body functions • caffeine, nicotine, amphetamines, cocaine

  21. DRUGS • Hallucinogens psychedelic (mind-manifesting) drugs that distort perceptions and evoke sensory images in the absence of sensory input • LSD • Barbiturates • drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgement

  22. DRUGS • Opiates (Narcotics) • opiates depress neural activity, temporarily lessening pain and anxiety • opium and its derivatives (morphine and heroin) • Amphetamines (Stimulants) • drugs that stimulate neural activity, causing speeded-up body functions and associated energy and mood changes

  23. DRUGS • Ecstasy (MDMA) • synthetic stimulant and mild hallucinogen • both short-term and long-term health risks • LSD • lysergic acid diethylamide • a powerful hallucinogenic drug • also known as acid • THC • the major active ingredient in marijuana • triggers a variety of effects, including mild hallucinations

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