PSYCHOLOGY: Themes and Variations Weiten and McCann Chapter 5 : Variations in Consciousness Copyright © 2007 by Nelson, a division of Thomson Canada Limited

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

Table of Contents 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)

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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

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

Table of Contents Sleep Stages: Cycling Through Sleep Stage 1: brief, transitional (1-7 min.) –alpha > theta –hypnic jerks Stage 2: sleep spindles (10-25 min.) Stages 3 & 4 : slow-wave sleep (30 min.) 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

Table of Contents Fig 5.5 – An overview of the cycle of sleep. The white line charts how a typical, healthy, young adult goes through the stages of night’s sleep. Dreams and rapid eye movements tend to coincide with REM sleep, whereas posture changes occur between REM periods (the body is nearly paralyzed during REM sleep). A person cycles into REM 4 times (not all shown), as descents into NREM sleep get shallower and REM periods get longer. Thus, slow-wave sleep is prominent early in the night, and REM sleep dominates later on. Sleep patterns vary from one person to another and they change with age.

Table of Contents 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

Table of Contents Fig 5.7 – The ascending reticular activating system (ARAS). A number of brain areas and structures interact to regulate sleep and waking. Particularly important is the ARAS (represented by the green arrows), which conveys neural stimulation to many areas of the cortex.

Table of Contents 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

Table of Contents 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

Table of Contents Fig Effect of sleep deprivation on cognitive performance. Subjects in the Pilcher and Walters (1997) study underwent 24 hours of sleep deprivation prior to taking the Watson-Glaser Critical Thinking Appraisal. As you can see, their performance on this cognitive test was clearly inferior to that of the control subjects, who had not experienced sleep deprivation.

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

Table of Contents Fig 5.10 – The vicious circle of dependence on sleeping pills. Because of the body’s ability to develop tolerance to drugs, using sedatives routinely to “cure” insomnia can lead to a vicious circle of escalating dependency as larger and larger doses of the sedative are needed to produce the same effect.

Table of Contents Fig Sleep problems and the cycle of sleep. Different sleep problems tend to occur at different points in the sleep cycle. Whereas sleepwalking and night terrors are associated with slow- wave sleep, nightmares are associated with the heightened dream activity of REM sleep.

Table of Contents 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

Table of Contents Fig 5.13 – Three theories of dreaming. Dreams can be explained in a variety of ways. Freud stressed the wish-fulfilling function of dreams. Cartwright emphasizes the problem-solving function of dreams. Hobson and McCarley assert that dreams are merely a byproduct of periodic neural activation. All three theories are rather speculative and have their critics.

Table of Contents 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

Table of Contents 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

Table of Contents 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 – produces a warm, friendly euphoria

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