Figures not included - D. Fry Science...Table of Contents Consciousness: Personal Awareness Awareness of Internal and External Stimuli –Levels of awareness •James – stream of

Chapter 5

Variations in Consciousness – 8th Edition

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Consciousness: Personal Awareness

Awareness of Internal and External Stimuli

– Levels of awareness

• James – stream of consciousness

• Freud – unconscious

• Sleep/dreaming research

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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 (

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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

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Sleep/Waking Research

Instruments:

– Electroencephalograph – brain electrical activity

– Electromyograph – muscle activity

– Electrooculograph – eye movements

– Other bodily functions also observed

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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

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

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

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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

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XX 5.8

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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

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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

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REM deprivation effects

Figure 5.9

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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

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Figure 5.10. Mortality rates as a function of typical sleep duration.

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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%)

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Sleep Needs

On average, adults sleep 6 hours and 54 minutes

during the workweek – recommended 8 hours

Younger adults (i.e., 18-29 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” - 15 -20 minutes of duration

“Power Sleep” – strategies for better sleep

Takes about four weeks to stabilize sleep cycle

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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

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XX 5.12

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Figure 5.13 – Sleep problems and the cycle of sleep

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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

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Figure 5.15 Three theories of dreaming

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Hypnosis: Altered State of Consciousness or Role Playing?

Hypnosis = a systematic procedure that increases suggestibility

Hypnotic susceptibility: individual differences – F 5.17 - Stanford Hypnotic Susceptibility Scale

Hilgrad’s neural disassociation (hidden observer)and Barber’s role theory

Effects produced through hypnosis: – Anesthesia

– Sensory distortions and hallucinations

– Disinhibition

– Posthypnotic suggestions and amnesia

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Figure 5.16 –

Misconceptions

regarding hypnosis

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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

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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

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Figure 5.19 – Stimulant drugs

and neurotransmitter activity

Figure 5.20 – The “reward

pathways” in the brain

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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”

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Figure 5.26 - Physiological

malfunctions associated with

alcoholism