• Sleep and Dreams
• Hypnosis
• Drugs and Consciousness
• Near-Death Experiences
• Meditation

• Spontaneous: daydreaming, drowsiness, dreaming
• Physiologically Induced: hallucinations, pain, hunger, lack of oxygen
• Psychologically induced: sensory deprivation, hypnosis, meditation

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.

Simons & Chabris (1999) Univ. Illinois

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.

Circadian 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.
Measuring Sleep
Eye
Muscle
Brain
Hank Morgan/ Rainbow

Brain (EEG)
Stage
 Awake, eyes closed
 Sleep: Stage 1
Awake
 Sleep: Stage 2 nonREM
 Sleep: Stage 3/4
 Sleep: REM
REM

Stages of Sleep
Rapid Eye Movement Sleep non-Rapid Eye Movement Sleep
Awake REM
EEG
EMG nonREM
EOG

• “Awake” EEG
• Muscular (skeletal) paralysis
• Eye movement
• Dreaming is common

Time asleep Stage 4 REM

Sleep  Accidents

• 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 onset
Growth hormone is released during the deep stages of sleep.
deep sleep

Longer sleep time improves the function of the immune system and helps fight off infection
More sleep = more immune system cells
Less sleep = fewer immune system cells

• 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

Less sleep leads to more arguments
More sleep leads to fewer arguments

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
Stimulate
Brain stem
( reticular activating system )
( locus coeruleus )
( raphe n.)
Awake
EEG desyn
ACh
5-HT
NE
Histamine
Hypocretin

Brain Mechanisms
Non-REM
Brain stem
(reticular activating system)
(locus coeruleus)
(raphe n.)
Sleep
EEG Syn
ACh
5-HT
NE

Brain Mechanisms
REM
Brain stem
(reticular activating system)
(locus coeruleus)
(raphe n.)
Sleep
EEG desyn
No muscle
ACh
5-HT
NE

Brain Mechanisms
Cerebral Cortex
Thalamus
Brainstem

• 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%)

• 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)

• Physiological Function: Develop neural pathways.
Babies develop many new neural connection and require more sleep.
• Cognitive Development: Brain maturation and cognitive development.

• 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.

One person (the hypnotist) suggests to another
(the subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur.
Hypnos: Greek god of sleep

Power of Suggestion
Can anyone experience hypnosis?
Yes, to some extent.
Can hypnosis enhance recall of forgotten events?
Can hypnosis force people to act against their will?
Can hypnosis be therapeutic?
No.
No.
Yes.
Can hypnosis alleviate pain?
Yes.

What Causes Hypnosis?
• Social Influence Theory: Playing acting; expectations.
• Divided Consciousness Theory : Special state of consciousness

Bad smell  attention is diverted
Social Influence Theory: told to ignore smell
Divided Consciousness Theory: consciousness/awareness split

Psychoactive Drug: A chemical substance that alters perceptions and mood (affects consciousness).
• Alcohol
• Amphetamines
• Barbiturates
• Caffeine
• Cocaine
• Ecstasy
• GHB
• Hallucinogenic Mushrooms
• Heroin
• Inhalants
• LSD
• Marijuana
• Nicotine
• PCP
• Rohypnol
• 1,4-Butanediol

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: 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 are divided into three groups.
1. Depressants
2. Stimulants
3. Hallucinogens

Depressants: reduce neural activity and slow body functions.
1. Alcohol
2. Barbiturates
3. Opiates

Alcohol: affects motor skills, judgment, and memory; increases aggressiveness while reducing self awareness.
Drinking and Driving

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: excite neural activity and speed up body functions.
• Caffeine
• Nicotine
• Cocaine
• Ecstasy
• Amphetamines
• Methamphetamines

Caffeine and nicotine increase heart and breathing rates and other autonomic functions to provide energy.

1. Socially rewarding.
2. Genetic factors.
3. Reduce unpleasant cravings
4. Rewarding

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.

(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

Distort perceptions; create sensory images without sensory input.
• LSD: (lysergic acid diethylamide) powerful hallucinogenic drug.
• THC (delta-9-tetrahydrocannabinol): major active ingredient in marijuana
(hemp plant)
Hemp Plant

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.