1 / 33

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.

thane-gay
Télécharger la présentation

Chapter 5

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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

More Related