states of consciousness. sleep and dreams hypnosis drugs and consciousness near-death experiences...
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States of Consciousness
• Sleep and Dreams
• Hypnosis
• Drugs and Consciousness
• Near-Death Experiences
• Meditation
States of Consciousness
Forms of Consciousness• Spontaneous: daydreaming, drowsiness, dreaming
• Physiologically Induced: hallucinations, pain, hunger, lack of oxygen
• Psychologically induced: sensory deprivation, hypnosis, meditation
Selective Attention
Our conscious awareness processes only a small part of all that we experience. We
intuitively make use of the information we are not consciously aware of.
Inattentional Blindness
Simons & Chabris (1999) Univ. Illinois
Change Blindness
Change blindness is a form of inattentional blindness in which two-thirds of individuals giving
directions failed to notice a change in the individual asking for directions.
© 1998 Psychonomic Society Inc. Image provided courtesy of Daniel J. Simmons.
Sleep & Dreams
Biological Rhythms and SleepCircadian Rhythms: “About a Day” – our biological clock
Body temperature, sleep/wake cycle, heart rate, hormone levels, neurotransmitter release
Light suprachiasmatic nucleus decreases pineal melatonin No Light SCN increases pineal melatonin
Measuring Sleep
Measuring Sleep
Sleep Cycle: each 90 minutes, we pass through a cycle of five distinct sleep stages.
Sleep Stages
Hank Morgan/ Rainbow
Eye
Muscle
Brain
Measuring Sleep
Sleep Stages
Awake, eyes closed
Sleep: Stage 1
Sleep: Stage 2
Sleep: Stage 3/4
Sleep: REM
Brain (EEG) Stage
Awake
nonREM
REM
Stages of Sleep
Rapid Eye Movement Sleepnon-Rapid Eye Movement Sleep
Awake REM nonREM
EEG
EMG
EOG
REM Sleep
• “Awake” EEG• Muscular (skeletal) paralysis• Eye movement• Dreaming is common
90-Minute Sleep Cycles
Time asleep Stage 4 REM
AccidentsSleep Accidents
Sleep Theories
• Protection: avoid danger• Conserve energy• Recovery/Repair: restore and repair brain tissue.
(exercise, sleep)• Memory: build memories.
(sleep, memory)• Growth: growth hormone (GH) released.
(Older people: growth hormone, sleep)
Sleep’s role in recovery/repair
Growth hormone is released during the deep stages of sleep.
deep sleep
Sleep onset
Recovery/RepairLonger sleep time improves the function of the immune system and helps fight off infection
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immune system cells
Less sleep = fewer immune system cells
Neuronal Energy Production• In wake promoting areas of the brain, ATP (the
energy currency of brain cells) increases during the first few hours of sleep.
• This surge in ATP increases with deeper stages of sleep.
1/3 of life asleep!
Sleep Deprivation
•Fatigue and subsequent death
•Impaired concentration
•Emotional irritability
•Depressed immune system
•Greater vulnerability
Why Sleep?
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Sleep loss impairs social interactions
Less sleep leads to more arguments
More sleep leads to fewer arguments
Sleep habits influencephysical health
Short sleep times (≤7 hrs per night) are associated with increased:
• Appetite• Body mass (obesity)• Risk of diabetes• Risk of cancer• Incidence of cardiovascular disease
Why Sleep?
Sleep is essential for life.
World record for no sleep = 11-12 days (264-288 hours) 18 days?
Hallucinations, vision/speech/memory problems but with full recovery.
Animal Sleep
20 hr 18 hr 16 hr
13 hr 4 hr 3 hr
Unusual Animal Sleep
New calves/mothers:No sleep for 3 weeks!
Unusual Animal Sleep
Brain Mechanisms
AWAKE
Brain stem(reticular activating system)(locus coeruleus)(raphe n.)
AwakeEEG desyn
Stimulate
ACh5-HTNEHistamineHypocretin
Brain Mechanisms
Non-REM
SleepEEG Syn
Brain Mechanisms
REM
SleepEEG desynNo muscle
Brain Mechanisms
Cerebral Cortex
Thalamus
Brainstem
Discover Sleep
Dream Journal
REM “Detective”
• Insomnia: Persistent inability to fall asleep. (30-40%)
• Narcolepsy: Overpowering urge to fall asleep that may occur while talking or standing up.
• Sleep apnea: Failure to breathe when asleep. (2-3%)
• Night terrors: Sudden arousal from sleep, intense fear, rapid heart rate, sweating, Stage 4 disorder.
• Sleepwalking: Stage 4 disorder, usually harmless, no recall (1-15%)
• Sleeptalking: Stage 1-4 disorder, runs in families
• Restless Legs Syndrome: unusual feelings at bedtime (10%)
Sleep Disorders
Why Dream?• Wish Fulfillment (Freud): safety valve to discharge
unacceptable feelings; symbolic meanings.
Problem: Theory lacks support; interpretation of dreams difficult.
• Information Processing: Dreams may help sift, sort, and fix a day’s experiences in our memories.
Problem: dreams can contain events
not experienced.
Sigmund Freud(1856-1939)
Why Dream?• Physiological Function: Develop neural pathways.
Babies develop many new neural connection and require more sleep.
• Cognitive Development: Brain maturation and cognitive development.
Why Dream?• Activation-Synthesis Theory: random neural
activity; dreams attempt to make sense of this activity.
REM sleep is essential!
If deprived of REM sleep, REM rebound occurs.
Hypnosis
Hypnos: Greek god of sleep
One person (the hypnotist) suggests to another (the subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur.
Hypnosis: Facts and Myths Power of Suggestion
Can anyone experience hypnosis? Yes, to some extent.
Can hypnosis enhance recall of forgotten events?
No.
Can hypnosis be therapeutic? Yes.
Can hypnosis alleviate pain? Yes.
Can hypnosis force people to act against their will?
No.
What Causes Hypnosis?
• Social Influence Theory: Playing acting; expectations.• Divided Consciousness Theory: Special state of
consciousness
ExampleBad smell attention is diverted
Social Influence Theory: told to ignore smell
Divided Consciousness Theory: consciousness/awareness split
Drugs and ConsciousnessPsychoactive Drug: A chemical substance that alters perceptions and mood (affects consciousness).
• Heroin• Inhalants• LSD• Marijuana• Nicotine• PCP • Rohypnol • 1,4-Butanediol
• Alcohol• Amphetamines • Barbiturates• Caffeine• Cocaine• Ecstasy• GHB • Hallucinogenic Mushrooms
Dependence & Addiction
Continued use of a psychoactive drug produces tolerance. With repeated exposure to a drug, the drug’s effect lessens. Thus it takes greater quantities to get the desired effect.
Withdrawal & Dependence
• Withdrawal: Upon stopping use of a drug (after addiction), users may experience the undesirable effects of withdrawal.
• Dependence: Absence of a drug may lead to a feeling of physical pain, intense cravings (physical dependence), and negative emotions (psychological dependence).
Psychoactive Drugs
Psychoactive drugs are divided into three groups.
1. Depressants
2. Stimulants
3. Hallucinogens
Depressants
Depressants: reduce neural activity and slow body functions.
1. Alcohol
2. Barbiturates
3. Opiates
DepressantsAlcohol: affects motor skills, judgment, and memory; increases aggressiveness while reducing self awareness.
Drinking and Driving
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Depressants
Barbiturates: reduce the activity of the central nervous system; reduce anxiety but impair memory and judgment.
Opiates (morphine and heroin): reduce neural activity, reduce pain and anxiety; highly addictive.
Stimulants
Stimulants: excite neural activity and speed up body functions.
• Caffeine • Nicotine• Cocaine• Ecstasy• Amphetamines• Methamphetamines
Caffeine & Nicotine
Caffeine and nicotine increase heart and breathing rates and other autonomic functions to provide energy.
Why Do People Smoke?
1. Socially rewarding.
2. Genetic factors.
3. Reduce unpleasant cravings
4. Rewarding
Cocaine
Cocaine induces immediate euphoria followed by a crash. Crack, a form of cocaine, can be smoked. Other forms of cocaine can be sniffed or injected.
Ecstasy(Methylenedioxymethamphetamine, MDMA)
Stimulant, mild hallucinogen.
Can damage serotonin-producing neurons
Possible depression, memory problems.
Image courtesy of Dr. GA Ricaurte, Johns Hopkins University School of Medicine
• LSD: (lysergic acid diethylamide) powerful hallucinogenic drug.
• THC (delta-9-tetrahydrocannabinol): major active ingredient in marijuana (hemp plant)
Hemp Plant
Hallucinogens
Distort perceptions; create sensory images without sensory input.
Drugs
Summary
After a close brush with death, many people report an experience of moving through a dark tunnel with a light at the end. Under the influence of hallucinogens, others report bright lights at the center of their field of vision.
Near-Death Experiences(From
“Hallucinations” by R
.K. Siegel. C
opyright ©
1977 Scientific Am
erican, Inc. All rights reserved.)
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