Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
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 Rhythms Jet 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 eastwardinduced 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 Less sleep, more accidents Accident frequency More sleep, fewer accidents 2,800 2,700 4,200 2,600 4000 2,500 3,800 2,400 3,600 Spring time change (hour sleep loss) Monday before time change Fall time change (hour sleep gained) Monday after time change 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 LO 4.1 Consciousness and Levels of 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 Consciousness • Altered State and ofLevels Consciousness LO 4.1 Consciousness of Consciousness • state in which there is a shift in the quality or pattern of mental activity as compared to waking consciousness Necessity of Sleep • Circadian rhythm: a Works cycle of bodily LO 4.2 Why Sleep and How Sleep rhythm that occurs over a twentyfour-hour period • “circa”: about • “diem”: day Necessity of Sleep • Hypothalamus: tiny of the LO 4.2 Why Sleep and How Sleep section Works 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: of sleep LO 4.2 Why Sleep and Howtheory Sleep Works proposing that animals and humans evolved sleep patterns to avoid predators by sleeping when predators are most active Necessity of Sleep • Restorative theory: of sleep LO 4.2 Why Sleep and How Sleeptheory Works proposing that sleep is necessary to the physical health of the body and serves to replenish chemicals and repair cellular damage 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 LO 4.2 Why Sleep and How Sleep Works (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 LO 4.3 Stages of Sleep and Dreaming 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 Stages of Sleep • Non-REM stage light sleep LO 4.3 Stages of Sleep1: and Dreaming • 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 3Dreaming and 4: delta LO 4.3 Stages of Sleep and 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. 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. 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. 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 isof paradoxical sleep (high LO 4.3 Stages Sleep and Dreaming 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 LO 4.4 Sleep Disorders and Normal Sleep • 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 Hallucinations • Hypnogogic Hallucination: LO 4.10 What Are Hypnogogic and Hypnopompic Hallucinations?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 Stage Four Sleep Disorders • Sleepwalking (Somnambulism) LO 4.4 Sleep Disorders and Normal Sleep • 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 LO terrors 4.4 Sleep Disorders and Normal Sleep • 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 LO 4.4 Sleep Disorders and Normal Sleepto 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 LO 4.4 Sleep Disorders and Normal Sleep a person falls immediately into REM sleep during the day without warning • cataplexy: sudden loss of muscle tone Dreams • Freud: dreams LO 4.5 Why People Dream andas What wish They Dream fulfillment about • manifest content: the dream itself • latent content: the true, hidden meaning of a dream Dreams • Activation-synthesis hypothesis: LO 4.5 Why People Dream and What They Dream about 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 LO 4.5 Why People Dream and What They Dream about (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 ofIt consciousness in LO 4.6 Hypnosis and How Works which the person is especially susceptible to suggestion Hypnosis • Four Elements of LO 4.6 Hypnosis and HowHypnosis: It Works • 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 dissociation: hypnosis LO 4.6 as Hypnosis and How It Works 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 LO 4.7 Physical and Psychological Dependence on a Drug 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 Psychoactive Drugs • Psychological dependence: the LO 4.7 Physical and Psychological Dependence on a Drug feeling that a drug is needed to continue a feeling of emotional or psychological well-being Stimulants • Stimulants: drugs increase the LO 4.8 How Do Stimulants and Depressantsthat Affect Consciousness? 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 Stimulants • Stimulants: drugs increase the LO 4.8 How Do Stimulants and Depressantsthat Affect Consciousness? functioning of the nervous system • caffeine: the stimulant found in coffee, tea, most sodas, chocolate, and even many over-the-counter drugs Depressants • Depressants: drugsAffectthat decrease LO 4.8 How Do Stimulants and Depressants Consciousness? 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: theandchemical resulting from LO 4.8 How Do Stimulants Depressants Affect Consciousness? fermentation or distillation of various kinds of vegetable matter • Often taken for a stimulant, alcohol is actually a depressant on the CNS. Level and Behavior Associated With Amounts of Alcohol Narcotics • Narcotics LO 4.9 Dangers of Narcotics, Hallucinogens, and Marijuana • 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 Hallucinogens • Psychogenic Drugs LO 4.9 Dangers of Narcotics, Hallucinogens, and Marijuana • 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 LO 4.9 Dangers of Narcotics, Hallucinogens,(cont’d) and Marijuana • 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 LO 4.9 Dangers of Narcotics, Hallucinogens,(cont’d) and Marijuana • psilocybin: natural hallucinogen found in certain mushrooms Marijuana • Marijuana (potHallucinogens, or weed): mild LO 4.9 Dangers of Narcotics, and Marijuana 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 Is True 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? Attention is diverted from an aversive odor. How? Divided-consciousness theory: hypnosis has caused a split in awareness Social Influence theory: the subject is so caught up in the hypnotized role that she ignores the odor