Chapter 6
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.
• Stream of consciousness: flow of thoughts,
feelings, and sensations
• Many levels of consciousness
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 Rhythm
LO 4.2 Why Sleep and How Sleep Works
: a cycle of bodily rhythm that occurs over
a twenty-four-hour period
• “circa”: about
• “diem”: day
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.
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.
Sleep
• A nonwaking state of consciousness
characterized by minimal physical
movement and responsiveness to
one’s surroundings.
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.
Necessity of Sleep
LO 4.2 Why Sleep and How Sleep Works
• 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.
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 Patterns of Infants and Adults
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.
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.
Brain Wave Patterns
• Electroencephalograph
LO 4.2 Why Sleep and How Sleep(EEG)
Works
• 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
Sleep
Stages of Sleep
• Non-REM stage
1:of Sleep
light
sleep
LO 4.3 Stages
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
LO 4.3 Stages of Sleep and Dreaming
• Non-REM stages 3 and 4: delta waves
pronounced
• deep sleep: when 50 percent or more of
waves are delta waves.
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.
First Cycle (90 Minutes) of Sleep
Stages of Sleep
• Rapid eye movement
LO 4.3 Stages of Sleep(REM):
and Dreaming 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
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.
REM Sleep and Dreaming
LO 4.3 Stages of 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
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.
Hallucinations
• Hypnogogic Hallucination: a type of
hallucination that can occur just as a
person is entering Stage 1 sleep
LO 4.10 What Are Hypnogogic and Hypnopompic Hallucinations?
• 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
Problems during Sleep
LO 4.4 Sleep Disorders and Normal 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
• CPAP: continuous positive airway pressure
device
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
Stage Four Sleep Disorders
LO 4.4 Sleep Disorders and Normal Sleep
• 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.
• Sleeptalking
Stage Four Sleep Disorders
LO 4.4 Sleep Disorders and Normal Sleep
• Night terrors
• relatively rare disorder in which the person
experiences extreme fear and screams or
runs around during deep sleep without
waking fully
Sleep Disorders
LO 4.4 Sleep Disorders and Normal Sleep
• 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
Problems Related to REM Sleep
LO 4.4 Sleep Disorders and Normal Sleep
• Narcolepsy: sleep disorder in which a
person falls immediately into REM sleep
during the day without warning
• cataplexy: sudden loss of muscle tone
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
LO 4.6 Hypnosis and How It Works
• Hypnosis: state of consciousness in
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
• 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: “Symptoms”
• When hypnotized, people’s awareness
may be characterized by:
•
•
•
•
•
Enriched fantasy,
Cognitive passivity,
Hyperselective attention,
Reduced reality testing
Posthypnotic amnesia.
Hypnosis: Experiences
•
•
•
•
Changes in perception
Failure to process pain
Posthypnotic Amnesia
Posthypnotic Suggestion
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