chapter 5 consciousness

Chapter 5

Consciousness

Consciousness

• Awareness of ourselves and our environment:• Subjective: own conscious experiences

• Selective attention: ability to focus awareness on a single stimulus

• Divided attention: different stimuli at the same time.

Consciousness

• Awareness of ourselves and our environment:

• Stream of consciousness: flow of thoughts, feelings, and sensations

• Many levels of consciousness

Sleep

• A nonwaking state of consciousness characterized by minimal physical movement and responsiveness to one’s surroundings.

Circadian Rhythms

• The behavioral cycle of sleep and wakefulness that we naturally follow throughout our lives

• Circadian rhythms correspond to physiological changes, such as body temperature, blood pressure, and hormone levels.

Circadian Rhythms

• Sleep-wakefulness cycles • A small area of the hypothalamus known as

the suprachiasmatic nucleus and the hormone melatonin, produced by the pineal gland, appear to be crucial in readjusting the body’s sleep-wake cycle.

Circadian RhythmsJet lag

• The severity of this jet lag depends on whether you fly westward or eastward.

• When flying westward your regular sleep cycle is pushed back five hours (a phase delay). The jet lag resulting from such east-west travel is easier to adjust to—and thus, less severe—than eastward-induced jet lag.

• When flying eastward your day is being shortened (a phase advance), which is not only farther away from your natural 24-hour sleep-wake cycle but also is inconsistent with people’s day-stretching habits.

EEG Brain Wave Patterns—NREM Sleep

EEG Brain Wave Patterns—REM Sleep

Stages of Sleep• Stage:1 hypnogogic state: transition between

wakefulness and sleep• myoclonic jerk; hypnogogic hallucinations

• Stage 2: lasts about 20 minutes and is characterized by sleep spindles

• Stage 3: slow-wave sleep; brain waves higher in amplitude and slower in frequency

• Stage 4: delta waves much more pronounced

• REM (rapid eye movement) sleep: “Active sleep” completes the sleep cycle.

The First 90 Minutes of Sleep

Why We Sleep

• Why do we sleep?• Body needs sleep and will malfunction

without a sufficient amount • Restorative theory:

• Sleep allows the body to restore itself following the rigors of daily activity.

• Safety/conservation theory:• It prevents us from moving about and being

injured. • It conserves energy.

• We honestly don’t know why we sleep.

Sleep Deprivation• Effects of Sleep Loss

• fatigue

• impaired concentration

• immune suppression

• irritability

• slowed performance• accidents

• planes• autos and trucks

Sleep Deprivation

2,400

2,700

2,600

2,500

2,800

Spring time change(hour sleep loss)

3,600

4,200

4000

3,800

Fall time change(hour sleep gained)

Less sleep,more accidents

More sleep,fewer accidents

Monday before time change Monday after time change

Accident frequency

Sleep Habits Vary by Age• Newborns sleep about 16 hours

• Children average between 9 and 12 hours

• Adolescents average about 7.5 hours.

• Newborns and young children have the highest percentage of REM sleep.

Many sleep experts believe that the heightened brain activity during REM sleep in the young promotes the development of new neural pathways.

Sleep Habits Vary by Age

• In adulthood, both quantity & quality of sleep decrease with age.

• Less time is spent in slow-wave sleep.

• There is more stage 1 sleep and more awakenings during the night.

• The percentage of REM sleep only diminishes in later life.

Sleep Habits Vary Individually

• Morning people (25%) wake up early, with a good deal of energy and alertness, but are ready to retire before 10:00 p.m.

• Night people (25%) stay up much later and have a hard time getting up early in the morning.

• This different sleep pattern appears to be related to differences in circadian body temperatures.

• Morning persons’ body temperatures rise quickly rise upon awakening. The body temperature of night persons rises gradually and peaks later.

Sleep Habits Vary Culturally

• People in industrialized settings sleep less.

• This may have to do with work.

• Electricity also extends the time people can be active and productive.

REM Sleep • REM phase of sleep is paradoxical.

• Brain waves are active.• Body is paralyzed.

• People dream during REM. • Eugene Aserinsky discovered the

association between rapid eye movement and dreaming.

• 78 % of people awakened from REM sleep report dreaming.

Importance of REM Sleep

• Participants deprived of REM sleep often report feeling more tired.

• They may experience dreamlike images during the day

• They spend extra time REM sleep following deprivation. This is called REM rebound.

Theories of Dreams • Biological Dream Theories

• Dreams as interpreted brain activity • Dreaming is simply a by-product of brain activity.

• Activation-synthesis theory• A dream is the forebrain’s attempt to interpret the

random neural activity initiated in the midbrain during sleep.

• There is no consensus on the cause or meaning of dreams.

Theories of Dreams • Psychological Dream Theories

• Dreams as wish fulfillment (Freud)• Dreams are disguised wishes originating in the

unconscious mind.

• Dreams as problem solving (emotions)• Dreams provide people with the opportunity to

creatively solve their everyday problems.

• Dreams as information processing (memory)• Off-line dream theory contends that the cognitive

processing that occurs during dreaming consolidates and stores information gathered during the day.

Sleep Disorders

• Insomnia

• Sleep apnea

• Narcolepsy – wide-awake to REM

• Parasomnias – Stage 3 or 4• Sleepwalking, sleeptalking• Night terrors

• REM sleep behavior disorder

Sleep Disorders

• Insomnia• recurring problems in falling or

staying asleep

• Narcolepsy• uncontrollable sleep attacks• sufferer may lapse directly into REM

sleep, often at inopportune times

Sleep Disorders

• Sleep Apnea• characterized by temporary cessations of

breathing during sleep and consequent momentary reawakenings

• Night Terrors• high arousal-appearance of being

terrified• usually in Stage 4, within 2-3 hours of

falling asleep

Consciousness• Consciousness

• a person’s awareness of everything that is going on around him or her at any given moment

• Waking Consciousness• state in which thoughts, feelings, and

sensations are clear and organized, and the person feels alert

LO 4.1 Consciousness and Levels of Consciousness

Consciousness• Altered State of Consciousness

• state in which there is a shift in the quality or pattern of mental activity as compared to waking consciousness

LO 4.1 Consciousness and Levels of Consciousness

Necessity of Sleep• Circadian rhythm: a cycle of bodily

rhythm that occurs over a twenty-four-hour period• “circa”: about• “diem”: day

LO 4.2 Why Sleep and How Sleep Works

Necessity of Sleep• Hypothalamus: tiny section of the

brain that influences the glandular system• suprachiasmatic nucleus: deep within

the hypothalamus; the internal clock that tells people when to wake up and when to fall asleep

• The hypothalamus tells the pineal gland to secrete melatonin, which makes a person feel sleepy.


Necessity of Sleep• Adaptive theory: theory of sleep

proposing that animals and humans evolved sleep patterns to avoid predators by sleeping when predators are most active


Necessity of Sleep• Restorative theory: theory of sleep

proposing that sleep is necessary to the physical health of the body and serves to replenish chemicals and repair cellular damage


Figure 4.1 Sleep Patterns of Infants and Adults

Infants need far more sleep than older children and adults. Both REM sleep

and NREM sleep decrease dramatically in the first 10 years of life, with the greatest decrease in REM sleep.

Nearly 50 percent of an infant’s sleep is REM, compared to only about 20

percent for a normal, healthy adult. (Roffwarg, 1966)

Brain Wave Patterns• Electroencephalograph (EEG)

• allows scientists to see the brain wave activity as a person passes through the various stages of sleep and to determine what type of sleep the person has entered

• alpha waves: brain waves that indicate a state of relaxation or light sleep

• theta waves: brain waves indicating the early stages of sleep

• delta waves: long, slow waves that indicate the deepest stage of sleep


Stages of Sleep• Rapid eye movement (REM): stage of

sleep in which the eyes move rapidly under the eyelids and the person is typically experiencing a dream

• NREM (non-REM) sleep: any of the stages of sleep that do not include REM

LO 4.3 Stages of Sleep and Dreaming

Stages of Sleep• Non-REM stage 1: light sleep

• may experience:• hypnagogic images: vivid visual events• hypnic jerk: knees, legs, or whole body

jerks

• Non-REM stage 2: sleep spindles (brief bursts of activity only lasting a second or two)


Stages of Sleep• Non-REM stages 3 and 4: delta

waves pronounced• deep sleep: when 50 percent or more of

waves are delta waves.


EEG Brain Wave Patterns—NREM Sleep

Stages of Sleep

• Stage:1 hypnogogic state: transition between wakefulness and sleep

• myoclonic jerk; hypnogogic hallucinations

• Stage 2: lasts about 20 minutes and is characterized by sleep spindles

• Stage 3: slow-wave sleep; brain waves higher in amplitude and slower in frequency

• Stage 4: delta waves much more pronounced

• REM (rapid eye movement) sleep: “Active sleep” completes the sleep cycle.

Figure 4.2 Brain Activity During Sleep

The EEG reflects brain activity during both waking and sleep. This activity varies according to level of alertness while awake (top two segments) and the stage of sleep (middle segments). Sleep Stages 3 and 4 are indicated by the presence of delta activity, which is

much slower and accounts for the larger, slower waves on these graphs.

Figure 4.2 (continued) Brain Activity During Sleep

[NOTE: The American Academy of Sleep Medicine (Iber et al., 2007) has recently published updated guidelines

for the scoring of sleep activity and one major change has been to combine NREM stages 3 and 4 into a single

stage, now indicated by N3.] REM has activity that resembles alert

wakefulness but has relatively no muscle activity except rapid eye

movement. The bottom segments illustrate how EEG activity differs

between wakefulness, light and deep sleep, and lastly what it looks like when

brain activity has ceased in cerebral death. EEG data and images in this

figure are courtesy of Dr. Leslie Sherlin.

Figure 4.3 A Typical Night’s SleepThe graph shows the typical

progression through the night of Stages 1–4 and REM sleep. Stages 1–4 are

indicated on the y-axis, and REM stages are represented by the green

curves on the graph. The REM periods occur about every 90 minutes

throughout the night (Dement, 1974).

The First 90 Minutes of Sleep

REM Sleep and Dreaming• REM sleep is paradoxical sleep (high

level of brain activity).

• If wakened during REM sleep, sleepers almost always report a dream.

• REM rebound: increased amounts of REM sleep after being deprived of REM sleep on earlier nights


Sleep Disorders• Nightmares

• bad dreams occurring during REM sleep

• REM Behavior Disorder• a rare disorder in which the mechanism

that blocks the movement of the voluntary muscles fails, allowing the person to thrash around and even get up and act out nightmares

LO 4.4 Sleep Disorders and Normal Sleep

Hallucinations• Hypnogogic Hallucination: a type of

hallucination that can occur just as a person is entering Stage 1 sleep

• Hypnopompic Hallucination: a hallucination that happens just as a person is in the between-state of being in REM sleep (in which the voluntary muscles are paralyzed) and not yet fully awake

LO 4.10 What Are Hypnogogic and Hypnopompic Hallucinations?

Stage Four Sleep Disorders• Sleepwalking (Somnambulism)

• Occurring during deep sleep, sleepwalking is an episode of moving around or walking around in one’s sleep. Sleepwalking is more common among children than adults.


Stage Four Sleep Disorders• Night terrors

• relatively rare disorder in which the person experiences extreme fear and screams or runs around during deep sleep without waking fully


Problems during Sleep• Insomnia: the inability to get to

sleep, stay asleep, or get a good quality of sleep

• Sleep apnea: disorder in which the person stops breathing for nearly half a minute or more• continuous positive airway pressure

device


Problems during Sleep• Narcolepsy: sleep disorder in which

a person falls immediately into REM sleep during the day without warning• cataplexy: sudden loss of muscle tone


Dreams• Freud: dreams as wish fulfillment

• manifest content: the dream itself• latent content: the true, hidden meaning

of a dream

LO 4.5 Why People Dream and What They Dream about

Dreams• Activation-synthesis hypothesis:

explanation that states that dreams are created by the higher centers of the cortex to explain the activation by the brain stem of cortical cells during REM sleep periods


Dreams• Activation-information-mode model

(AIM): revised version of the activation-synthesis explanation of dreams in which information that is accessed during waking hours can have an influence on the synthesis of dreams


Hypnosis• Hypnosis: state of consciousness in

which the person is especially susceptible to suggestion

LO 4.6 Hypnosis and How It Works

Hypnosis• Four Elements of Hypnosis:

• The hypnotist tells the person to focus on what is being said.

• The person is told to relax and feel tired.• The hypnotist tells the person to “let

go” and accept suggestions easily.• The person is told to use vivid

imagination.

• Hypnotic susceptibility: degree to which a person is a good hypnotic subject


Hypnosis

• Unhypnotized persons can

also do this

Theories of Hypnosis• Hypnosis as dissociation: hypnosis

works only in a person’s immediate consciousness, while a hidden “observer” remained aware of all that was going on.

• Social-cognitive theory of hypnosis: theory that assumes that people who are hypnotized are not in an altered state, but are merely playing the role expected of them in the situation


Psychoactive Drugs• Psychoactive drugs: drugs that alter

thinking, perception, and memory

• Physical Dependence• tolerance: more and more of the drug is

needed to achieve the same effect• withdrawal: physical symptoms that can

include nausea, pain, tremors, crankiness, and high blood pressure, resulting from a lack of an addictive drug in the body systems

LO 4.7 Physical and Psychological Dependence on a Drug

Psychoactive Drugs• Psychological dependence: the

feeling that a drug is needed to continue a feeling of emotional or psychological well-being

LO 4.7 Physical and Psychological Dependence on a Drug

Stimulants• Stimulants: drugs that increase the

functioning of the nervous system• amphetamines: drugs that are

synthesized (made in labs) rather than found in nature

• cocaine: natural drug; produces euphoria, energy, power, and pleasure

• nicotine: active ingredient in tobacco

LO 4.8 How Do Stimulants and Depressants Affect Consciousness?

Stimulants• Stimulants: drugs that increase the

functioning of the nervous system• caffeine: the stimulant found in coffee,

tea, most sodas, chocolate, and even many over-the-counter drugs


Depressants• Depressants: drugs that decrease

the functioning of the nervous system• barbiturates: depressant drugs that

have a sedative effect• benzodiazepines: drugs that lower

anxiety and reduce stress• Rohypnol: the “date rape” drug


Alcohol• Alcohol: the chemical resulting from

fermentation or distillation of various kinds of vegetable matter• Often taken for a stimulant, alcohol is

actually a depressant on the CNS.


Table 4.5 (continued) Blood Alcohol Level and Behavior Associated With

Amounts of Alcohol

Narcotics• Narcotics

• A class of opium-related drugs, narcotics suppress the sensation of pain by binding to and stimulating the nervous system’s natural receptor sites for endorphins.

• opium: substance derived from the opium poppy from which all narcotic drugs are derived

• morphine: narcotic drug derived from opium; used to treat severe pain

• heroin: narcotic drug derived from opium that is extremely addictive

LO 4.9 Dangers of Narcotics, Hallucinogens, and Marijuana

Hallucinogens• Psychogenic Drugs

• drugs including hallucinogens and marijuana that produce hallucinations or increased feelings of relaxation and intoxication

• hallucinogens: drugs that cause false sensory messages, altering the perception of reality

• LSD (lysergic acid diethylamide): powerful synthetic hallucinogen

• PCP: synthesized drug now used as an animal tranquilizer that can cause stimulant, depressant, narcotic, or hallucinogenic effects


Hallucinogens• Psychogenic Drugs (cont’d)

• MDMA (Ecstasy or X): designer drug that can have both stimulant and hallucinatory effects

• Stimulatory hallucinogenics: drugs that produce a mixture of psychomotor stimulant and hallucinogenic effects

• Mescaline: natural hallucinogen derived from peyote cactus buttons


Hallucinogens• Psychogenic Drugs (cont’d)

• psilocybin: natural hallucinogen found in certain mushrooms


Marijuana• Marijuana (pot or weed): mild

hallucinogen derived from the leaves and flowers of a particular type of hemp plant• This woman is preparing a cannabis

(marijuana) cigarette. Cannabis is reported to relieve pain in cases of multiple sclerosis and chronic pain from nerve damage. Such use is controversial as cannabis is classified as an illegal drug in some countries.


Hypnosis

• A state of altered attention and awareness in which a person is unusually responsive to suggestions?

Hypnosis

• Hypnosis• a social interaction in which one

person (the hypnotist) suggests to another (the subject) that certain perceptions, feelings, thoughts or behaviors will spontaneously occur

Hypnosis

• People differ in their hypnotizability, the degree to which they can enter a deep hypnotic state.

• Individuals who are highly hypnotizable have the ability to concentrate totally on material outside themselves and to become absorbed in imaginative activities.

Hypnosis

• Changes in perception

• Failure to process pain

• Posthypnotic Amnesia

• Posthypnotic Suggestion

Hypnosis

• When hypnotized, people’s awareness may be characterized by:

• Enriched fantasy,• Cognitive passivity,• Hyperselective attention,• Reduced reality testing• Posthypnotic amnesia.

Common Misconceptions about Hypnosis

• People can be forced to violate their moral values.

• Memory is more accurate under hypnosis.

• People are much stronger than normal.

• Acts like a truth serum, compelling people to avoid deception

• People can be age-regressed, thus allowing them to relive childhood experiences.

Hypnosis

• Unhypnotized persons can

also do this

Some Psychologists Doubt Hypnosis Is an Altered State

• Social Influence Theory

• Spanos proposed that a hypnotized person is simply playing a role.

• In some studies, people pretending to be hypnotized perform exactly like hypnotized subjects.

• Orne & Evans (1965) control group instructed to “pretend”

• unhypnotized subjects performed the same acts as the hypnotized ones

Some Psychologists Believe Hypnosis IsTrue Dissociation

• Hilgard’s Neo-dissociation theory says there are two streams of consciousness: • One responds to the hypnotist’s suggestions.- The other stream, the hidden observer, remains

concealed from conscious awareness.

- EEGs of hypnotized persons differ slightly from normal waking state

- The debate about hypnosis being an altered state is a matter of ongoing scientific inquiry.

Hypnosis and Pain

• Dissociation• a split in consciousness• allows some thoughts and behaviors to

occur simultaneously with others

• Hidden Observer• Hilgard’s term describing a hypnotized

subject’s awareness of experiences, such as pain, that go unreported during hypnosis

Hypnosis

• Divided Consciousness or Social Phenomenon?

Social Influencetheory:

the subject is so caughtup in the hypnotized role that she ignores

the odor

Attention is divertedfrom an aversive odor.

How?

Divided-consciousnesstheory:

hypnosis has caused asplit in awareness

chapter 5 consciousness

Documents

active sleep

agenewborns sleep

sleep experts

regular sleep cycle

body needs sleep

sleep spindles stage

hour sleepwake cycle

bodys sleepwake cycle