Upload
aileen-rolison
View
222
Download
0
Tags:
Embed Size (px)
Citation preview
Chapter 5
Variations in Consciousness
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)
Mental state and cortical activity – correlation issue – F 5.1
Table of Contents
Table of Contents
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
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 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 ContentsFigure 5.5 An overview of the cycle of sleep
Table of ContentsFigure 5.5 An overview of the cycle of sleep
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
Table of Contents
XX 5.8
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– 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
Table of Contents
REM deprivation effects
Figure 5.9
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
Table of Contents
Figure 5.10. Mortality rates as a function of typical sleep duration.
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%)
Table of Contents
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
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
Table of Contents
XX 5.12
Table of Contents
Figure 5.13 – Sleep problems and the cycle of sleep
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
Table of ContentsFigure 5.15 Three theories of dreaming
Table of Contents
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
Table of Contents
Figure 5.16 – Misconceptions regarding hypnosis
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
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
Table of Contents
Table of Contents
Table of Contents
Figure 5.19 – Stimulant drugs and neurotransmitter activity
Figure 5.20 – The “reward pathways” in the brain
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”
Table of Contents
Figure 5.26 - Physiological malfunctions associated with alcoholism