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Chapter 5: Variations in Consciousness 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

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the nature of consciousness
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!
variations in consciousness
Variations in Consciousness
  • Levels of awareness
    • Consciousness is not all-or-none
      • Awake
      • Sleep
      • Anesthesia
      • Coma
      • Persistent Vegetative State
      • Death
definitions of death
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)
the electroencephalograph a physiological index of consciousness
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)
biological rhythms and sleep
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
sleep waking research
Sleep/Waking Research
  • Instruments:
    • Electroencephalograph – brain electrical activity
    • Electromyograph – muscle activity
    • Electrooculograph – eye movements
    • Other bodily functions also observed
sleep stages cycling through sleep
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
the neural bases of sleep
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
why do we sleep
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
sleep deprivation
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
sleep problems
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
types of insomnia
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
dreams and dreaming content and significance
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
hypnosis altered state of consciousness or role playing
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
meditation
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
psychoactive drugs
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
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Table 5.3 Psychoactive Drugs: Tolerance, Dependence, Potential for Fatal Overdose, and Health Risks