CHAPTER 4
consciousness
Consciousness
• Consciousness
– a person’s awareness of everything that is
going on around him or her at any given
moment
– Essentially, a series of neurons fire and send
messages throughout the brain
• Waking consciousness
– state in which thoughts, feelings, and
sensations are clear and organized, and the
person feels alert
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
– Can be an increase in awareness (stimulant)
– Can also be divided
 Driving example
Sleep
• Most commonly achieved state of altered
consciousness
• Circadian rhythm: a cycle of bodily rhythm
that occurs over a twenty-four-hour period
– “circa”: about
– “diem”: day
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
• Hypothalamus tells the pineal gland to
secrete melatonin
– melatonin makes a person feel sleepy
How it works
• Responsive to
light
• As light fades,
tells pineal gland
to secrete
melatonin
• As light dawns in
the morning, tells
it to stop
• Serotonin may
also play a role in
sleep
Necessity of Sleep
• Microsleeps: brief sidesteps into sleep
lasting only a few seconds
• Sleep deprivation: any significant loss of
sleep
– We probably all suffer from this
– results in irritability and problems with
concentration
Sleep Deprivation
• Most of us have probably pulled an all-nighter
– But some people have tested how far they can go
 http://www.hotelcontractbeds.co.uk/sleep-deprivation/
• Other effects:
– Decaying of brain
– May cause weight gain
– May be more likely to fall back on habits
– False memories
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
– Then, predators should be able to sleep for a
long time
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
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
Figure 4.1 Sleep Patterns of Infants and Adults
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
Figure 4.2 Brain Activity During Sleep
Stages of Sleep
• Stage 1: light sleep
– may experience:
 hypnagogic images: hallucinations or vivid visual
events
 hypnic jerk: knees, legs, or whole body jerks
• Stage 2: sleep spindles
– sleep spindles: brief bursts of activity only
lasting a second or two
Stages of Sleep
• Stages 3 and 4: delta waves pronounced
– deepest stage of sleep: 50 percent or more of
waves are delta waves
– body at lowest level of functioning
– time at which growth occurs
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
Figure 4.3 A Typical Night’s Sleep
Sleep Disorders
• Nightmares
– bad dreams occurring during REM sleep
• REM behavior disorder
– mechanism that blocks the movement of the
voluntary muscles fails
– allows the person to thrash around, or even
get up and act out nightmares
 http://www.youtube.com/watch?v=rFXYRQ9xPUA
Stage Four Sleep Disorders
• Sleepwalking (somnambulism)
– episode of moving around or walking around
in one’s sleep
– occurs in deep sleep
– more common among children than adults
Stage Four Sleep Disorders
• Night terrors
– the person experiences extreme fear and
screams or runs around during deep sleep
– doesn’t wake fully
– relatively rare disorder
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
(CPAP)
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
– http://www.youtube.com/watch?v=1PuvXpv0y
DM
Dreams
• Freud: dreams as wish fulfillment
– manifest content: the dream itself
– latent content: the true, hidden meaning of a
dream
Dreams
• Cartwright: problem solving view
– Dreams are a way to think through problems
– We play out the various scenarios as we
sleep
Dreams
• Activation-synthesis hypothesis: dreams
are created by the higher centers of the
cortex to explain the brain stem’s
activation of cortical cells during REM
sleep periods
Figure 4.4 The Brain and Activation-Synthesis Theory
According to the activation-synthesis theory of dreaming, the pons in the brainstem sends random signals to
the upper part of the brain during REM sleep. These random signals pass through the thalamus, which sends
the signals to the proper sensory areas of the cortex. Once in the cortex, the association areas of the cortex
respond to the random activation of these cortical cells by synthesizing (making up) a story, or dream, using
bits and pieces of life experiences and memories
Dreams
• Activation-information-mode model (AIM)
– revised version of the activation-synthesis
explanation of dreams
– information that is accessed during waking
hours can have an influence on the synthesis
of dreams
– This might be why it seems to include relevant
events
Hypnosis
• Hypnosis: state of consciousness in which
the person is especially susceptible to
suggestion
Hypnosis
• Four elements of hypnosis:
1. hypnotist tells the person to focus on what is
being said
2. person is told to relax and feel tired
3. hypnotist tells the person to “let go” and
accept suggestions easily
4. person is told to use vivid imagination
• Hypnotic susceptibility: degree to which a
person is a good hypnotic subject
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
– The hidden part of the mind is aware of the
hypnotic subject’s activities and sensations, even
though the “hypnotized” part of the mind is
unaware
Theories of Hypnosis
• Social-cognitive theory of hypnosis: people
who are hypnotized are not in an altered
state, but are merely playing the role
expected of them in the situation
– assumes that people who are hypnotized are not
in an altered state but are merely playing the role
expected of them in the situation
– Social roles/situations are very powerful
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 resulting from a
lack of an addictive drug in the body systems
 can include nausea, pain, tremors, crankiness, and high
blood pressure
Psychoactive Drugs
• Psychological dependence: the feeling that a
drug is needed to continue a feeling of
emotional or psychological well-being
– May not physically need the drug, may not
experience withdrawal or tolerance, but they think
they need it
– Any drug can become a focus of psychological
dependence
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
– caffeine: the stimulant found in coffee, tea,
most sodas, chocolate, and even many overthe-counter drugs
Nicotine
• The harmful effects of nicotine are now well
known, but many people continue to smoke or
chew tobacco in spite of warnings
– Produces addiction in 99% of the people who use
it
– Physical withdrawal symptoms can be as bad as
those resulting from alcohol, cocaine, or heroin
abuse
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 (roofies)
Alcohol
• Alcohol: the chemical resulting from
fermentation or distillation of various kinds
of vegetable matter
– often mistaken for a stimulant, alcohol is
actually a CNS depressant
– gives the illusion of stimulation because the
first thing alcohol depresses is a person’s
natural inhibitions
Alcohol
• Risk for psychiatric disorders increases
from about 2.5% for a light drinker to 13.2%
for a moderate drinker and around 17.1%
for a heavy drinker
– Also increase for liver disease and other health
problems
• Alcoholism
– Feelings of guilt/shame, binge drinking, drinking
alone, lying/denial, memory loss
Alcohol
• There are numerous disorders that can be
caused by alcoholism in addition to liver
disease
– Korsakoff’s syndrome – a form of dementia brought about
by a severe vitamin B1 deficiency, caused by the
alcoholic’s tendency to drink rather than eat
– Babies born to mothers who drank during pregnancy are
likely to be born with a condition of mental retardation and
physical deformity called fetal alcohol syndrome
– Alcoholism has also been linked to loss of bone density
and heart disease
Narcotics
• Narcotics
– opium-related drugs
– suppress the sensation of pain by binding to
and stimulating the nervous system’s natural
receptor sites for endorphins.
 opium: substance made from the opium poppy and
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
– 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
Hallucinations
• Hypnogogic hallucination: hallucination
that can occur just as a person is entering
N1 sleep
• Hypnopompic hallucination: 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
QUESTIONS?