Consciousness & Its Variants Psychology 2012 – Spring 2004.

Consciousness & Its Variants

Psychology 2012 – Spring 2004

Consciousness

• Personal awareness of mental activities, internal sensations, and the external environment– William James called it a “stream” of

consciousness • Always changing, yet flowing in an unbroken

manner

Biological & Environmental “Clocks”

• Circadian rhythm – a cycle that is roughly 24 hours long

• Examples of Human Circadian Rhythms– Peak mental alertness – around 9 AM & 9 PM

– Peak physical strength – around 11 AM & 7 PM

– Lowest sensitivity to pain – around 3 PM-5 PM

– Highest sensitivity to pain – around 3 AM-5 AM

– Peak degree of sleepiness – around 3 AM & 3 PM


• Two mechanisms influence sleep1. The suprachiasmatic nucleus (SCN) – a cluster of

neurons in the hypothalamus in charge of the timing of the sleep-wake cycle and the mental alertness cycle

2. Eyes detect a decrease in light, and melatonin production is increased• Melatonin – hormone produced by the pineal gland that

makes us more sleepy and reduce our activity levels– Production of melatonin typically peaks between 1AM-3AM– Production of melatonin typically slows right before sunrise


• Free-running circadian rhythms – rhythms that are not allowed to be affected by environmental cues like sunlight and clocks– People begin to move toward a 25 hour rhythm– When sunlight and clocks are allowed back in, people go

back to a 24 hour rhythm within days

• Circadian rhythms and sunlight – what happens when your internal clock is not matched up with environmental cues?– Jet lag may result

• Thinking, concentration, & memory get fuzzy• Fatigue, depression, irritability, & disrupted sleep


• Why jet lag?– Major reason = melatonin is out of alignment

with the environment• 10 AM in London = 3 AM in Denver

– Instead of feeling refreshed, you feel groggy and sleepy

Sleep

• Electroencephalograph – device invented in the 1920’s that measures and records the brain’s electrical activity

• REM sleep – type of sleep during which there is rapid eye movements and dreaming, and voluntary muscle movement is suppressed – AKA active sleep or paradoxical sleep

• NREM sleep – quiet, usually dreamless sleep divided into four stages– AKA quiet sleep

The Onset of Sleep

• Beta brain waves – brain wave pattern associated with alert wakefulness

• Alpha brain waves – brain wave pattern associated with relaxed wakefulness– Hypnagogic hallucinations – vivid sensory

phenomena that can occur during the onset of sleep• Common = sensation of falling, often accompanied by a

myoclonic jerk

Stages of Sleep

• Stage 1 NREM – begins when beta brain waves begin to be replaced by slower theta waves; lasts only a few minutes– Easily awakened – Often some images of normal, daily activities are reported

• Stage 2 NREM – represents the onset of true sleep; theta waves w/ some delta waves (slower, larger waves)– Characterized by short bursts of brain activity called sleep spindles

• Last about a second or two

• Stage 3& 4 NREM – very similar; characterized by delta brain waves– Blood pressure, heart rate, breathing at their lowest levels– Difficult to wake up if awoken during these stages– AKA as slow wave sleep

Stages of Sleep

• REM sleep – visual and motor neurons in the brain fire repeatedly just as they do when awake; the sleeper’s eyes dart back and forth behind the eyelids– Voluntary muscle activity is suppressed

– After the first 90 minutes of sleep, REM periods become longer and NREM periods become shorter

Changes in Sleep Patterns Across the Lifespan

• Over the course of our lives, the quantity and quality of our sleep changes– Time spent sleeping

= decreases

– Time in slow wave NREM sleep = decreases

Why Sleep?

• Sleep deprivation studies – participants are not allowed to sleep– REM deprivation – participants are allowed to sleep,

but are awakened when REM sleep begins• REM rebound – when allowed to sleep uninterrupted, the

amount of time spent in REM sleep increases

– NREM deprivation – participants are allowed to sleep, but are awakened when stages 3&4 NREM sleep begins

• NREM rebound – when allowed to sleep uninterrupted, the amount of time spent in stages 3&4 NREM sleep increases

Sleep Theories

• Restorative theory of sleep – theory that sleep promotes physiological processes that restore & rejuvenate the body & the mind– NREM – restores the body– REM – restores mental and brain functions

• Adaptive theory of sleep – theory that sleep patterns evolved over time to help promote survival and adaptation to the environment– AKA evolutionary theory of sleep

More Sleep Disorders

• Sleep bruxism – person grinds the teeth loudly during sleep

• REM sleep behavior disorder – person acts out his or her dreams– May be caused by damage in the lower brain centers that

control physical & mental arousal during sleep

• Parasomnias – category of sleep disorders that involve arousal or activation during sleep or sleep transition– Sleepwalking, night terrors, sleep bruxism, REM sleep

behavior disorder

Dreams and Mental Imagery During Sleep

• Sleep thinking – repetitive and uncreative thoughts about real-life events during sleep

• Dream – a storylike episode of mental imagery during sleep

– J. Allan Hobson – dreams have 5 basic characteristics1. Emotions are intense2. Content and organization are typically illogical3. Sensations can be strange4. Strange details are accepted without question5. Images are often difficult to remember


• The brain during REM sleep – brain activity is different than when awake or when in NREM sleep

– Primary visual cortex and frontal lobes are shut down• This cuts people off from information about the external

world and from centers of rational thought

– Amygdala and hippocampus are highly active• Structures in the limbic system involved with emotion &

memory


• REM & memory consolidation – studies have shown that REM sleep increases after learning a new task

– And that disrupting REM sleep after training disrupts learning

• What do we dream about?– Researcher Calvin Hall states that dreams often

reflect the daily concerns of the dreamer– Certain dream themes, such as falling, being chased,

and being attacked are common themes across cultures


• Why don’t we remember our dreams?– Making remembering more likely

1. We are more likely to remember our dreams if we wake up during them

2. The more vivid, bizarre, or emotionally intense a dream is, the more likely we will remember them

3. Distractions upon awakening interfere with our ability to recall dreams

– It is difficult to remember any experience during sleep, not simply dreams


• The significance of dreams – there are many theories regarding dreams– Sigmund Freud – founder of psychoanalysis;

thought that dreams were symbolic representations of unconscious wishes and urges• Two components of dreams

1. Manifest content – the actual dream images2. Latent content – the disguised meaning of the dream

images


• Another theory regarding dreams– The activation-synthesis model of dreaming

– dreaming is our subjective awareness of the brain’s internally generated signals during sleep • Dreaming is due to activation of the brain stem,

which activates more sophisticated brain areas– The brain then synthesizes the internally generated

signals into a dream» Brain synthesizes memory fragments, emotions,

and internal sensations


• Another theory regarding dreams– The Gestalt Therapy approach – dreams are

“messages” that only you can interpret accurately• The role of the therapist = help the client to make rational

sense of the dream and decode the message– Decoded dreams can help clients become aware of more

information about themselves

– The meaning of dreams – interpretation of dreams may tell more about the interpreter than about the meaning of the dream

Hypnosis

• An unusual state of awareness in which a person responds to suggestions with changes in perception, memory, and behavior

– Best candidates for hypnosis = those with positive, receptive attitudes regarding hypnosis

– Effects of hypnosis• Sensory and perceptual changes – such as hallucinations,

temporary blindness, deafness, or loss of sensation in an area

• Posthypnotic suggestions – a suggestion made during hypnosis that the person carry out a specific instruction following the hypnotic session

Hypnosis

• Hypnosis and memory – hypnosis can affect memory in many ways

1. Posthypnotic amnesia – memory is suppressed by a hypnotic suggestion

2. Pseudomemories – hypnosis can greatly increase confidence in false memories

3. Hypermnesia – claims have been made that hypnosis can improve memory

– There is currently no proof that hypnosis improves memory

Hypnosis

• Explaining hypnosis – psychologist Ernest Hilgard believes that the hypnotized person experiences dissociation

– The splitting of consciousness into two or more streams of mental activity

– The neodissociation theory of hypnosis • Hypnotized person consciously experiences the hypnotist’s

suggestions and• Another stream of consciousness is dissociated and

processing unconscious information – “Hidden observer”

Meditation

• One of a number of concentration techniques that focus attention and heighten awareness

– Two basic categories1. Concentration techniques – focusing your awareness on

something• Your breath, a word, a visual image

2. Opening up techniques – paying attention to the present moment without judging it in any way

– Effects of meditation – there are many effects of meditation

• Lower physiological arousal– Lower blood pressure, decreased heart rate, changes in brain

waves (alpha brain waves)

Psychoactive Drugs

• Drugs that alter consciousness, perception, mood, and behavior– Common properties of psychoactive drugs

• Addiction – a state of feeling psychologically and/or physiologically compelled to take a specific drug

Psychoactive Drugs

• Common properties of psychoactive drugs, continued – Physical dependence – a condition in which a person’s body and brain

have adapted to the drug• Tolerance – a state of needing more of the drug in question in order to

achieve the original effect of the drug• Withdrawal symptoms – unpleasant physical reactions to the lack of a drug,

along with intense craving for the drug– Drug rebound effect – withdrawal symptoms that are opposite of the

drug’s original effect» E.g., stimulating drugs = fatigue and depression; depressant drugs =

excitability and nervousness

• Drug abuse – recurrent drug use that results in disruptions in academic, social, or occupational functioning– Or in legal or psychological problems

Psychoactive Drugs

• Alter consciousness by influencing neurotransmitters

• Many illegal, or legal only for medical uses

Drug Categories

• Depressants

• Stimulants

• Hallucinogens/Psychedelics

• Narcotics

Depressants

• Slow down the Central Nervous System (CNS)

– alcohol

– barbiturates

– tranquilizers (benzodiazapines)

– sedatives

Alcohol Effect

• Death• Unconsciousness• Loss of motor control• Clouded judgement• Reduced motor skills• Reduced inhibitions

#

DRINKS

Alcohol

• 14 million Americans have alcohol problems– 7 million considered alcoholic

• Low level of dependence = certain withdrawal symptoms– Disrupted sleep, anxiety, tremors

• Higher level of dependence = more severe withdrawal symptoms– Confusion, hallucinations, severe tremors/seizures,

even death• Delirium tremens “DTs”

Barbiturates

• Death (overdose is easy)

• Unconsciousness

• Loss of motor control

• Clouded judgement

• Slowed reactions

Amount

Tranquilizers

• Mild CNS depressants

• Rarely used recreationally

• Can be fatal if used with alcohol

How Depressants Work

Barbiturates, sedatives

Attaches toGABA

receptors

Slows firing ofCNS neurons

Stimulants

• Speed up the CNS

– amphetamines

– cocaine

– nicotine

– caffeine

Amphetamines

Low Doses

Reduced fatigue, increased energy, reduced appetite

High Doses

Paranoia, confusion, damage to brain

capillaries

Cocaine

Low Doses

Intense, short-term euphoria

High Doses

Paranoia, irregularheartbeat, death

Nicotine

• Mildly stimulating, quite addictive, highly toxic

• Associated with a wide variety of illnesses

Caffeine

Low Doses

Mild stimulant.Increase alertness.

High Doses

Causes hostility,anxiety, “jitteriness”

More Psychoactive Drugs

• Stimulants – Caffeine – increases mental alertness &

wakefulness• Found in coffee, tea, cola, chocolate, and many

over-the-counter drugs• Most widely used psychoactive drug in the world

– Nicotine – increases mental alertness and reduces fatigue

• Found in tobacco products

How Stimulants Work

Cocaine, amphetamines

Reduced dopamine reuptake

Reduced norepinephrine

reuptake

Pleasurablesensations

Alertness, activity

Hallucinogens/Psychedelics

• Cause sensory distortions, hallucinations

– LSD

– PCP

– mescaline

– marijuana

LSD

• Causes marked visual hallucinations, sensory distortions

• Induces powerful emotional feelings

• Negative hallucinations and emotions can lead to suicide, panic, or dangerous actions

• Flashbacks (a return of the hallucinations) may occur days, months, or years later

Marijuana

• Relieves anxiety, inhibitions

• Reduces memory performance

PCP

Low Doses

Mild euphoria

High Doses

Tactile hallucinations,magnification of senses

Narcotics

• Derivatives of the opium poppy

• Reduce pain, cause euphoria

– heroin – morphine– opium– codeine

Heroin

• Produces powerful euphoria, deadens pain

• Highly physiologically addictive • Attaches to endorphin sites• Causes death in large doses

Morphine & Codeine

• Highly effective pain killers

• Addictive when used recreationally, not highly addictive when used just to relieve pain

How Narcotics Work

Heroin, morphine

Attaches toendorphin

sites

Slows firing ofpain neurons

Consciousness & Its Variants Psychology 2012 – Spring 2004.

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Transcript of Consciousness & Its Variants Psychology 2012 – Spring 2004.