Chapter 5Consciousness

©2013 W. W. Norton & Company, Inc.

Gazzaniga • Heatherton • Halpern

FOURTH EDITION

Psychological SciencePsychological Science

Consciousness

• Erik Ramsey is “locked in…”•  Suffered traumatic injury to his brain

as the result of an automobile accident

• He can see, hear and feel, but he cannot move or communicate with the outside world…at least not yet

Consciousness

• In a coma, but aware• Patterns of brain activity in a coma

sufferer were similar to patterns found in those not in a coma (Owen et al., 2006)

• Communication may be possible with coma patients previously believed to be unreachable

5.1 What Is Consciousness?

Learning Objectives • Define consciousness.• Identify varied states of

consciousness.• Summarize research findings on

consciousness and “the interpreter” among individuals with split brain.

• Discuss how unconscious processes influence thought and behavior.

What Is Consciousness?

• People can be conscious even when they appear not to be

• All conscious experience is associated with brain activity

• Variations in consciousness occur naturally

• Consciousness can be manipulated• Conscious experience varies from

person to person

Consciousness Is a Subjective Experience

• Consciousness: The subjective experience of the world, resulting from brain activity

• The brain and the mind are inseparable

• Each of us experiences consciousness personally

• We cannot know if two people experience the world in exactly the same way

There Are Variations in Conscious Experience

• Sleep/wake cycle• Automatic tasks– Driving, walking, catching a baseball

• Controlled processing – Helps us perform in complex or novel

situations

Extreme States

• Conditions of impaired consciousness provide useful points of contrast to “normal” (fully-functioning) consciousness

 • Persistent vegetative state • Full coma that lasts more than a month• Terri Schiavo  • Minimally conscious state • Deliberate movement and communication

are possible • Jan Grzebski

Brain Activity Gives Rise to Consciousness

• Psychologists can examine and measure consciousness (e.g., fMRI)

• Consciousness arises from brain circuits’ activity

The Global Workplace Model

• In some cases brain-injured patients are unaware of their deficits (“hemineglect”)

• Consciousness arises through brain processes that are active at any point in time

• No single area of the brain responsible for general “awareness”

The Split Brain

• Awareness of the world is associated with functioning in different parts of the brain

The Split Brain

• Corpus callosum removed• Two halves of the brain cannot receive

information directly from each other• Studies show the relation between

specific brain regions and conscious experience

• Early observations were that split-brain patients had no discernable problems

• Sperry & Gazanniga’s (1960s) research proved otherwise

The Split Brain

• Language center located in left hemisphere

• Split brain patients cannot report on an object presented in their left visual field

• They could correctly choose the object (with their left hand)

 • Right hemisphere handles spatial tasks• Split-brain patients could not arrange

blocks correctly when using their right hand

• Left-handed, the task was effortless

The Interpreter

• The left hemisphere attempts to make sense of right-hemisphere actions

The Interpreter Speculates

• The left hemisphere tries to make sense of the world (e.g., imposing narrative structure, seeking patterns)

• The right hemisphere simply experiences the world

• Brain hemispheres work together to construct our experience of the world

Unconscious Processing Influences Behavior

• We are aware of some mental processes and unaware of others

• Subliminal perception: Processing information by sensory systems without conscious awareness

• Freudian slip: An unconscious thought expressed at an inappropriate moment

• Stereotype activation: Is it automatic?– Bargh et al. (1996) found research

participants primed with stereotypes about the elderly unconsciously behaved in ways consistent with those stereotype

The Smart Unconscious

• Good advice: “You’d better sleep on it.”

 • Unconscious processing of problems

can lead to superior solutions (Dijksterhuis, 2004)

 • Even conscious thinking can

undermine good decision- making (Wilson & Schooler, 1991)

5.2 What Is Sleep?

Learning Objectives • Describe the stages of sleep.• Identify common sleep disorders.• Discuss the functions of sleep and

dreaming.

What Is Sleep?

• Sleep is biologically regulated• Circadian rhythms• Melatonin secretion linked to light-

dark cycles• Some adults report needing 7-9

hours a night• 70-year-old “Miss M.” gets by on one

hour per night!

Sleep Is an Altered State of Consciousness

• Sleep: Awareness of the outside world is turned off (mostly)

• So why don’t we fall out of bed? • EEG: The brain is active in sleep

Stages of Sleep

• Sleep is not an “on-off” event• Sleep stages• Historically: 5 distinct stages• Currently: Stages 3 & 4 are now

joined

REM Sleep

• The sleep cycle reverses after about 90 minutes

• Enter REM (paradoxical) stage• Most dreaming occurs in REM sleep• Amount of time spent in REM

increases • Cycle through this pattern around 5

times per night

Sleep Disorders

• Insomnia: Difficulty falling or staying asleep

• Obstructive Sleep Apnea: Breathing may stop hundreds of times per night

• Narcolepsy: Sufferers unexpectedly fall asleep

• REM Behavior Disorder: Sufferers act out their dreams

• Somnambulism: Sleep walking

Sleep Is an Adaptive Behavior

• Sleep serves important biological purposes:– Restoration– Circadian rhythms– Facilitation of learning

Restoration and Sleep Deprivation

• Restorative Theory: Sleep allows the body to rest and repair itself

• The evidence:– Sleep increases after strenuous physical

activity– Growth hormones secreted in sleep– Replenishes the brain’s energy stores – Strengthens the immune system

Restoration and Sleep Deprivation

Effects of sleep deprivation: • Mood problems (e.g., irritability)• Decrements in cognitive performance

(e.g., attention and short-term memory lapses)

• May compromise the immune system• Falling asleep for a few seconds to a

minute (microsleeps) can impair ability to perform critical tasks (e.g., driving)

Circadian Rhythms

Circadian rhythm theory: • Many creatures are quiet and

inactive during the night because darkness is the time when danger is highest

• Reduced risk of exposure to predators

 • Humans: Are adapted to sleep at

night because our early ancestors were more at risk in the dark

Facilitation of Learning

Sleep: Strengthens neural connections needed for learning to occur

• Research shows memory in participants who slept was greater than those who didn’t (Drosopoulos, Schulze, Fischer, & Born, 2007)

• REM and slow-wave (stages 3 & 4) important for learning to take place

• Participants who completed a complex task and later dreamed about it subsequently performed better on the task than non-dreaming participants (Wamsley, Tucker, Payne, Benavides, & Stickgold, 2010)

• Students spend more time in REM during exam periods

People Dream while Sleeping

•  Dreams: Products of an altered state of consciousness in which images and fantasies are confused with reality

REM Dreams and Non-REM Dreams

• REM dreams: More likely to be bizarre and include intense emotions, visual and auditory hallucinations, and uncritical acceptance of illogical events

 • Non-REM dreams: Relatively dull

(e.g., what sweater should I wear?)

REM Dreams and Non-REM Dreams

Explanation: • Non-REM: General de-activation of

many brain regions• REM: Brain structures associated

with motivation, emotion, reward, vision are active; pre-frontal cortex is not

What Do Dreams Mean?

Freud: Dreams contain hidden content that represents

unconscious conflicts• Manifest content: The plot of a dream; the

way the dream is remembered• Latent content: What a dream symbolizes;

the material that is disguised in a dream to protect the dreams from confronting direct reality

• No scientific evidence that dreams represent hidden conflicts or for the special symbolic meaning of dream images

Activation-Synthesis Theory

The theory:• The brain tries to make sense of

random brain activity that occurs during sleep by synthesizing the activity with stored memories (Hobson et al., 2000)

• Emotion centers (limbic system) in the brain are active, which explains the intense emotions; frontal cortices are not active, which explains the uncritical acceptance of illogical events

Activation-Synthesis Theory

The critics: • Dreams are not as chaotic as the

activation-synthesis theory suggests (Domhoff, 2003)

• Often similar to “everyday life” waking experience

Evolved Threat-Rehearsal Theory

• Thought question: Why do people often dream about threatening events?

• Answer: Perhaps dreams help us prepare to cope with real waking events.

 • Dreams sometimes simulate

threatening events so that people can rehearse strategies for coping (Revonsuo, 2000)

• Dreams may have adaptive value if rehearsal helps us survive and reproduce

5.3 What Is Altered Consciousness?

Learning Objectives• Discuss the effects of hypnosis and

mediation on consciousness.• Define the concept of flow. • Discuss the consequences of

escaping the self.

What Is Altered Consciousness?

• Awareness varies naturally over the course of the day

 • Potentially altered by: hypnosis,

meditation, and immersion in an action (i.e., flow)

Hypnosis Is Induced through Suggestion

• Hypnosis: A social interaction during which a person, responding to suggestions, experiences changes in memory, perception, and/or voluntary action

• Induction: Hypnotist makes a series of suggestions

• “You are becoming sleepy. Your eyelids are drooping”

 • If all goes well, the subject(s) behave in ways

consistent with suggestions• Hypnosis works primarily for people who are

highly suggestible (1 in 5 persons)

Theories of Hypnosis

• Sociocognitive Theory: Hypnotized subjects are role-playing (i.e., acting how they believe hypnotized subjects are supposed to act)

• Dissociation Theory: Hypnosis is a “trance-like” state where conscious awareness is separated from other aspects of consciousness

• Strongest evidence for dissociation theory: Numerous studies show the analgesic effects of hypnotic analgesia

Hypnosis for Pain

• Hypnotic analgesia: Clinical evidence shows hypnosis can be used to treat immediate (e.g., surgery, burns) and chronic (e.g., arthritis, cancer) pain (Patterson & Jensen, 2003)

• Self-hypnosis: Also be shown to be effective in improving recovery from surgery

• Clinical evidence: Hypnosis doesn’t reduce the sensation of pain, but rather alters our interpretation (i.e., perception) of it

Meditation Produces Relaxation

• Meditation: A mental procedure that focuses attention on an external object or on a sense of awareness

Effects of meditation: • One study found greater stress reduction

and attention among participants who meditated compared to a group that underwent relaxation training (Tang et al., 2007)

• Another study showed that when participants were made to feel sad, those who received meditation training were less sad than those who had not (Farb et al., 2010)

People Can Lose Themselves in Activities

• We are unaware of most of what we think and do…

 • There are activities in which we can

“lose ourselves” and enter an altered state

Exercise, Religious Prayer, and Flow

• Runner’s high: Involves a shift in consciousness away from the self (endorphins too) accompanied by euphoria

• Religious ecstasy: Directs attention away from the self and toward spiritual awareness

• “Flow”: Total engagement in an act for its own sake (not focused on reward or on escaping one’s problems)

Escaping the Self

• Escapist behaviors include: drug and alcohol use, excessive television viewing, surfing the Web, texting, playing of video games (e.g., World of Warcraft)

• Purpose of escapist behavior: Distracts people from their problems; helps them avoid feeling bad about themselves

Escaping the Self

• Escapist behavior reduces self-awareness, which can lead to:– Lowered long-term planning (e.g., poor

foresight)– Reduced meaningful thought (e.g., less

effective at anticipating consequences of one’s actions)

– Lowered inhibitions

5.4 How Do Drugs Affect Consciousness?

Learning Objectives• Describe the neurochemical,

psychological, and behavioral effects of marijuana, stimulants, MDMA, opiates, and alcohol.

• Identify physiological and psychological factors associated with addiction.

How Do Drugs Affect Consciousness?

• Drugs have been used throughout history to create altered states

• Around 250 million people use illicit drugs each year (United Nations Office on Drugs and Crime, 2009)

• Other widely-used drugs include alcohol, prescription medications, caffeine and nicotine

• Drugs are a mixed blessing

People Use—and Abuse—Many Psychoactive Drugs

• Drugs are useful in the treatment of many medical conditions, but recreational drug use can have negative consequences

People Use—and Abuse—Many Psychoactive Drugs

• Psychoactive drugs: Mind altering substances that change the brain’s neurochemistry (marijuana, cocaine, amphetamines, MDMA, opiates)

• Drug effects: The effects of a particular drug depends on which neurotransmitter system it activates (e.g., methamphetamine acts on the dopamine system)

Marijuana

• Most widely used illicit drug• Not easily categorized as a stimulant,

depressant, or hallucinogen• Produces a relaxed, contented mood, more

vivid perceptions• Experienced users appreciate the effects

more than novices (Kuhn, Swartzwelder, & Wilson, 2003)

• Psychoactive ingredient: THC • Operates at cannabanoid receptors• Medical use is controversial

Cocaine

• Long history of use in the United States (Coca-Cola)

• Stimulant• Users experience increased alertness,

increased confidence and sociability• Increases dopamine levels at synapses• Habitual use of cocaine in large

quantities can lead to paranoia, psychotic behavior, and violence (Ottieger, Tressell, Inciardi, & Rosales, 1992)

Amphetamines

• Long history of use for weight loss, staying awake

• Seldom used for legitimate medical purposes

• Methamphetamine: World’s second most commonly used illicit drug

• Increases dopamine production; blocks reuptake

• Damages brain structures responsible for cognition, memory and emotion (Kim et al., 2006; Thompson et al., 2004)

• Causes considerable physical damage

MDMA• “Ecstasy” has gained in popularity

since the “raves” of the 1990s• High school students’ use increased

from 3.7% to 4.7% between 2009 and 2010 (National Institute of Drug Abuse, 2010)

• Users feel energized and may hallucinate

• Lowers dopamine; increases/depletes serotonin availability

• May produce depression, memory loss, difficulty in completing complex tasks (Fischer et al., 1995; Kalechstein et al., 2007)

Opiates

• Used historically to relieve severe pain • Depressant• Heroin, morphine, codeine• Users experience analgesia, relaxation,

euphoria• Highly addictive due to effects at opiate

receptors (pleasure) and dopamine receptors (increased wanting of the drug)

• Long-term use can lead to attention and memory problems (Gruber, Silveri, & Yurgelun-Todd, 2007)

Alcohol Is the Most Widely Abused Drug

• On the one hand: Moderate drinking is an accepted aspect of social interaction

• On the other hand: Alcohol is a major contributor to many social ills…

• Spousal abuse• Traffic fatalities• Unsafe sex • Loss of productivity at work

Gender Differences in Alcohol Consumption across Cultures• According to the World Health

Organization, when compared to women, men are twice as likely to report:– Binge drinking– Chronic drinking– Recent alcohol intoxication

• What accounts for observed gender differences? – Women metabolize alcohol slower than

men and can get the same effects while consuming less

– Women’s drinking may be hidden/unreported

Expectations• Many people drink because they

believe alcohol will have a positive effect on their emotions and behavior:– Improve social skills – Enhance sexual pleasure – Boost confidence and power

• Evidence for the power of learned beliefs: Research participants who believed that they had drank alcohol acted in ways consistent with people who actually consumed it (Hull & Bond, 1986)

Addiction Has Physical and Psychological Aspects

• Addiction: Drug use that remains compulsive despite its negative consequences

• Physical dependence involves:– Tolerance: Increasing amounts of a drug is

needed to achieve the intended effect– Withdrawal: Physiological and

psychological state characterized by feelings of anxiety, tension, and cravings for the addictive substance

• Psychological dependence involves: Drug cravings without tolerance or withdrawal

Addiction’s Causes

Why do people become addicted? Physiological: • Activation of brain dopamine systems

that play a role in the pleasurable experience drugs create and regions (the insula) that govern cravings

• Heredity may play a role (e.g., alcoholism)

Psychological: • The “sensation-seeking” personality

trait• Social learning (e.g., “modeling” of

drug use by significant others)

Addiction’s Context

• We cannot ignore the effects of social and environment context when explaining addiction

• Robins, Helzer and Davis (1975) conducted a large-scale study of 898 U.S. soldiers during Vietnam War

• The researchers found widespread drug use (over 90%) among U.S. soldiers

• 1 in 5 returned to the United States addicted to drugs

• Once home, approximately 95% of the addicts quit using drugs

• Removed from the stress of combat, they no longer needed drugs to escape