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Chapter 5 Variations in Consciousness. Table of Contents Consciousness: Personal Awareness Awareness of Internal and External Stimuli –Levels of awareness.

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Presentation on theme: "Chapter 5 Variations in Consciousness. Table of Contents Consciousness: Personal Awareness Awareness of Internal and External Stimuli –Levels of awareness."— Presentation transcript:

1 Chapter 5 Variations in Consciousness

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

3 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) Mental state and cortical activity – correlation issue – F 5.1

4 Table of Contents

5 Biological Rhythms and Sleep Circadian Rhythms – 24 hr biological cycles –Regulation of sleep/other body functions – F 5.2 Physiological pathway of the biological clock: –Light levels -> retina -> suprachiasmatic nucleus of hypothalamus -> pineal gland -> secretion of melatonin Melatonin and circadian rhythms Performance effects – Recht et al. (1995) study of professional baseball – F 5.3

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

7 Table of Contents Sleep Stages: Cycling Through Sleep Stage 1: brief, transitional (1-7 minutes) – see F 5.4 –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 (initially a few minutes, progressively longer as cycle through the stages) –Developmental differences in REM sleep – F 5.6 How quickly one falls asleep, how long one sleeps, how one cycles through the various stages – F 5.5 Varies from one person to the next – cultural differences – F 5.7 Each of us has a signature sleep pattern mostly shaped by biological factors rather than personal habits

8 Table of Contents Figure 5.5 An overview of the cycle of sleep

9 Table of Contents Figure 5.5 An overview of the cycle of sleep

10 Table of Contents The Neural Bases of Sleep Brain Structures: - F 5.8 –Ascending reticular activating system –Pons, medulla, thalamus, hypothalamus, limbic system Neurotransmitters: –Acetylcholine and serotonin –Also norepinephrine, dopamine, and GABA

11 Table of Contents XX 5.8

12 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

13 Table of Contents Sleep Deprivation Complete deprivation –3 or 4 days max –Maximum duration? Partial deprivation or sleep restriction –impaired attention, reaction time, coordination, and decision making –accidents: Chernobyl, Exxon Valdez, bus crashes, airline crashes Selective deprivation –REM and slow-wave sleep: rebound effect – F 5.9

14 Table of Contents REM deprivation effects Figure 5.9

15 Table of Contents Sleep Loss and Health Sleep loss can affect physiological processes Sleep restriction appears to trigger hormonal changes that increase hunger Studies have found a link between short sleep duration and increased obesity Mortality rates are especially high among those who consistently sleep over 10 hours – F 5.10

16 Table of Contents Figure Mortality rates as a function of typical sleep duration.

17 Table of Contents Sleep Deprivation effects 43 % of adults are chronically sleep deprived Mood shifts, decreased socialization & sense of humor Decreased motor and cognitive performance Reduced ability to concentrate and decision skills Reduced ability to handle complex tasks Increased risk taking behavior and accidents (driving) Decreased efficiency of immune system Decreased functioning of frontal lobes Increased microsleeps and daytime sleepiness (43%)

18 Table of Contents Sleep Needs On average, adults sleep 6 hours and 54 minutes during the workweek – recommended 8 hours Younger adults (i.e., year-olds) sleep an average of 6 hours and 48 minutes during the week and an hour longer on the weekend Adolescents need 9.25 hours of sleep – 20 % fall asleep in school Younger children require 10 or more hours of sleep Power Nap minutes of duration Power Sleep – strategies for better sleep Takes about four weeks to stabilize sleep cycle

19 Table of Contents 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 5.11, F 5.12 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

20 Table of Contents XX 5.12

21 Table of Contents Figure 5.13 – Sleep problems and the cycle of sleep

22 Table of Contents Dreams and Dreaming: Content and Significance Dreams – mental experiences during sleep –Content usually familiar –Common themes – F 5.14 –Waking life spillover – day residue Western vs. Non-Western interpretations Freud – wish fulfillment – manifest content and latent content – F 5.15 Hobson & McCarley – activation – synthesis hypothesis – F 5.15

23 Table of Contents Figure 5.15 Three theories of dreaming

24 Table of Contents Hypnosis: Altered State of Consciousness or Role Playing? Hypnosis = a systematic procedure that increases suggestibility Hypnotic susceptibility: individual differences – F Stanford Hypnotic Susceptibility Scale Hilgrads neural disassociation (hidden observer)and Barbers role theory Effects produced through hypnosis: –Anesthesia –Sensory distortions and hallucinations –Disinhibition –Posthypnotic suggestions and amnesia

25 Table of Contents Figure 5.16 – Misconceptions regarding hypnosis

26 Table of Contents Sensory Deprivation and Meditation McGill University sensory deprivation study Psychology of Boredom – problems with participation and altered states Meditation = practices that train attention to heighten awareness and bring mental processes under greater voluntary control – F 5.18 Yoga, Zen, transcendental meditation (TM) –Potential physiological benefits Similar to effective relaxation procedures

27 Table of Contents Principal Abused Drugs and Their Effects 6 categories of psychoactive drugs – Table 5.2 –Narcotics (opiates) – pain relieving - OxyContin –Sedatives – sleep inducing – effects GABA –Stimulants – increase CNS activity – effects on dopamine – F 5.19, methamphetamine –Hallucinogens – distort sensory and perceptual experience –Cannabis – produce mild, relaxed euphoria – F 5.21 –Alcohol – produces relaxed euphoria, decreases in inhibitions –MDMA – Ecstacy produces a warm, friendly euphoria – problems of temperature regulation – effects serotonin Brain reward pathways – dopamine and limbic system – Figure 5.20 Drug dependency and tolerance – physical and psychological – Table 5.3

28 Table of Contents


30 Figure 5.19 – Stimulant drugs and neurotransmitter activity Figure 5.20 – The reward pathways in the brain

31 Table of Contents Questions about Sleeping and Dreaming Variations in length of sleep – F 5.22 Suggestions on improving quality of sleep – F 5.23 Anxiety and sleep difficulties – F 5.24 – possible classical conditioning Thinking and insomnia – F 5.25 Alcoholism a disease ? –Malfunctions as a result of acoholism – F 5.26 –Genetic basis –Learned behaviors –Problems with a definition of a disease

32 Table of Contents Figure Physiological malfunctions associated with alcoholism

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