Biological Rhythms
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Regular fluctuations in our bodily processes and
in consciousness over time
Circadian rhythms—fluctuations that occur in a
single day
We have circadian rhythms in body temperature,
hormones, blood pressure, etc.
Many people peak in late afternoon or evening;
gets earlier with age
Best work done when body temp & internal
processes are at a peak
Suprachiasmatic nucleus (SCN)
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A structure in the hypothalamus that plays
a key role in biological clock
Not totally unresponsive to the outside
world.
Light is a zeitgeber (time giver)—resets
our clock each morning
Our biological clock operates on a 25-hour
cycle, not a 24-hour one.
Morning vs. Night People
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Morning people feel more active & alert early in
the day; night people feel more active/alert in
afternoon or evening.
Morning people have higher overall level of
adrenaline & operate at a higher level of
activation
Morning people peak in body temp earlier in the
day
Morning people get higher grades in morning
classes; evening people—higher grades in
evening classes
Jet lag
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Difficulty adjusting your internal clock to a
new location across time zones
Harder to fly west to east than east to west;
harder to fly into darkness
Shift work
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Work that requires you to work at times
when you would normally be sleeping
About 20% of U.S. employees work at
night
Linked to poorer job performance,
increased accidents, poor health
Controlled vs. automatic
processing
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Two levels of processing in waking
consciousness—controlled & automatic
Automatic: takes very little conscious awareness;
occurs seemingly beyond your control; rapid,
efficient, inflexible processing
Controlled: more effortful concentration; slower,
more deliberate, more flexible than automatic
Automatic & controlled operate on a continuum.
They’re not either/or.
Stages of Sleep
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Four distinct stages, plus REM (rapid eye
movement) sleep
With each stage, brain waves become
slower
We cycle through all the stages (including
REM) every 90-100 minutes
Stage 1 Sleep
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Characterized by the relaxed alpha waves
(awake) being replaced by theta waves
during stage 1
Lasts up to 5 minutes
May experience “hallucinations” during
this stage
Hypnogogic sleep—halfway between
wakefulness and sleep
Stage 2 Sleep
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Lasts about 20 minutes
Periodic appearance of sleep spindles
(bursts of rapid, rhythmic brain activity)
Can be awakened fairly easily, but you are
clearly asleep in this stage
Stage 3 Sleep
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Transitional stage between light stage 2
and deep stage 4
Large slow delta waves (at least 20% are
delta waves)
Stage 4 Sleep
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Stage of deep sleep
Together, stages 3 and 4 are known as
“slow-wave sleep”
Lasts for 30 minutes; hard to awaken from
Bedwetting and sleepwalking usually occur
in this stage
At least 50% of brain waves are delta
REM sleep
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Occurs about an hour after you first fall asleep
Brain waves become fast, saw-toothed for 10
minutes or so, similar to stage 1 sleep.
Heart rate rises, breathing becomes fast &
irregular, and eyes move rapidly every 30
seconds or so
Genitals become aroused, except during very
scary dreams.
Diagram of brain waves during
sleep
More on REM sleep
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Essentially paralyzed because brainstem
blocks messages from the motor cortex
Can’t be awakened easily
Called “paradoxical sleep”—internal state
is aroused, but external state is calm.
Gets longer as the night wears on.
Accounts for 20-25% of total night’s sleep
Dreams
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Can be recalled more than 80% of the time if
you’re awakened during REM. Have to make
conscious effort to remember dreams when you
first wake up.
Dreams are never acted out because we’re
“paralyzed.”
Visual & auditory centers of brain are active
when dreaming but inactive during other stages
of sleep
Lucid dreaming
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When you know you’re dreaming
Sometimes you even have the ability to
wake yourself up from a dream.
Dream Content
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80% of dreams are negative in nature
Women dream of males & females equally,
but 65% of the characters in men’s dreams
are males.
Manifest content—(Freud)—the story line
of a dream
Latent content—(Freud)—the dream’s
hidden meaning
Psychoanalytic view of dreams
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Freud
Dreams represent unconscious desires or
impulses
Dreams can be interpreted to reveal hidden
meaning (e.g., a tree is a phallic symbol; a
bowl is a symbol of female genitalia)
Absolutely no evidence that this view is
true.
Activation-synthesis theory
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Dreams are the subjective experience of
random neural activity in the brain that
originates in the pons.
The visual and language centers of the
cortex try to make sense of the neural
signals and weave a story about it.
Amygdala gets involved and adds
emotional content.
Neurocognitive view of dreams
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Dreams are the cognitive system’s efforts to
interpret activity in our brains while we sleep
Children have simpler dreams than adults because
they don’t have the cognitive maturity adults do.
Dreams reflect aspects of our memories &
waking experience b/c they represent
interpretations of neural activity by our brains.
Dream content is more stable over time and
across cultures than what “random neural
activity” would predict.
Information-processing view
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Dreams may help us sort out the day’s
activities and fix the experiences in
memory.
REM sleep is known to facilitate memory.
If you don’t sleep enough, you won’t learn
as well.
Sleep deprivation
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Results in a “sleep debt” that is related to
decreases in immune system, susceptibility
to accidents, lowered glucose tolerance, &
increased activity in the sympathetic
nervous system.
Insomnia
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The most common sleep disorder—40% of
adults occasionally experience it, 10-15%
of adults have it chronically
Increases with age; more common among
women
Sometimes people don’t realize they’re
asleep when they really are, and they think
they have insomnia when they don’t
Narcolepsy
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Disorder in which sleep occurs at inappropriate
and unexpected times
Sleep attacks lasting for a few minutes at random
times
Cataplexy: falling down suddenly when
narcoleptic attacks occur. Person falls into REM
sleep, and muscles become paralyzed.
Onset is late teens, early 20s
Living with Narcolepsy
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http://www.youtube.com/watch?v=3MBCe
Kn0Oeo
Somnambulism
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Sleepwalking
Associated with slow-wave sleep
Occurs at least once in 25% of all children
Night terrors
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Related to sleepwalking
People (especially children) awaken from deep
sleep, mainly stage 4, with signs of intense
arousal and powerful feelings of fear
No memory of any dreams associated with night
terrors
Related, along with sleepwalking, to disturbances
in functioning of autonomic nervous system
Nightmares are found during REM sleep; night
terrors are in stage 4. Nightmares can be
recalled; night terrors aren’t.
Sleep apnea
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A disorder in which one actually stops
breathing during sleep, causing the person
to wake up multiple times a night
1 in 25 people suffer from it, usually
overweight men
Associated with decrease in oxygen, which
triggers waking
Hypnosis
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http://www.youtube.com/watch?v=uP8j2OwPwU
c&feature=related
A special interaction between two people in
which one induces changes in the behavior,
feelings, or cognitions of the other through
suggestions
Involves expectations on the part of subjects &
their attempts to conform to social roles
Experts still aren’t sure if hypnosis is “real.”
Characteristics of hypnotic ability
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About 10-15% of adults are highly
susceptible; 10% are highly resistant, and
the rest fall somewhere in between
1. Expect to respond to hypnotic suggestion
2. Positive attitudes toward hypnosis
3. Prone to vivid fantasies
4. Able to become deeply involved in
sensory and imaginative experiences
Can hypnosis enhance recall of
forgotten events?
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60 years of research have failed to establish
a link
Hypnotically refreshed memories can’t be
treated as fact, although there have been
cases in which one’s recall has definitely
been enhanced through hypnosis
Potential for hypnotically refreshed
memories to become pseudomemories
Can you hypnotize someone to
perform something dangerous or
against their will?
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Orne & Evans (1965)—study with subjects
dipping hand in “acid” & throwing the
“acid” in someone’s face
Control Ss who were told to pretend they
were hypnotized did the same thing
Even unhypnotized people can be led to
perform dangerous acts if told to do so
Can hypnosis be therapeutic or
alleviate pain?
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Yes—hypnosis has helped alleviate headaches,
asthma, stress-related skin conditions, and warts
Helps obese people lose weight
Definitely helps alleviate pain. 10% of people can
be hypnotized to the point of not needing
anesthesia during surgery.
Does not seem to benefit smoking cessation or
drug and alcohol addictions
How does hypnosis help alleviate
pain?
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Dissociation theory: We experience a split
between different levels of consciousness.
May dissociate the pain stimulus from the
actual interpretation and experience of pain
Selective attention theory: We simply don’t
focus on the pain.
Is hypnosis really an altered state
of consciousness?
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We don’t know
Social influence theory: Hypnotized people
are just behaving (subconsciously or not)
as they think the hypnotist expects.
Hilgard’s theory
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Hilgard (a hypnosis researcher) says that
hypnosis involves not only social influence
but also a special state of dissociated or
divided consciousness.
Hypnotic dissociation is a vivid form of
everyday mind splits. Behavior starts
becoming automatically controlled rather
than consciously contolled.
The “hidden observer”
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Hilgard’s view that there’s a “hidden
observer” in your consciousness that
passively watches what’s happening in
your hypnotized state.
The two splits in consciousness, then, are
the “hidden observer” and “autopilot.” No
longer in direct contact with each other.
Controversial viewpoint
What’s the bottom line with
hypnosis?
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Remains a mystery
Seems to be neither real nor fake
Can produce dramatic effects, especially in
pain relief
Growing evidence indicates that hypnosis
is not anything special but is simply a
modest enhancement of nonhypnotic
suggestibility
Consciousness-altering drugs
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Four categories
1. Depressants
2. Stimulants
3. Opiates/psychedelics
4. Hallucinogens
Depressants
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Drugs that reduce both behavioral output and
activity in the central nervous system
Most common depressant is alcohol
Alcohol dulls senses, makes discomfort become
less intense
Interferes with coordination & normal
functioning of our senses
Lowers social inhibitions
Causes accidents
Depressant because it prevents neurons from
conducting impulses
Genetic component of alcoholism
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Two patterns of alcohol abuse—steady drinkers
and binge drinkers
Steady drinking seems strongly influenced by
heredity; binge drinking is influenced by both
heredity and environment
Binge drinking is related to variations in the
ALDH2 gene, which not everyone has.
Presence of ALDH2 related to LESS binge
drinking
Ethnic differences in binge
drinking
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Whites are most likely to binge drink; less
common among Koreans, and least
common among Chinese
Chinese and Korean students possessed the
ALDH2 gene more often.
Barbiturates
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Sleeping pills and relaxants
Depress activity in the CNS & reduce activation
and mental alertness
Reduce the release of excitatory neurotransmitters
by neurons in different locations
High doses—initially produce feelings of
euphoria/drunkenness. Then produce confusion,
slurred speech, memory lapses, impaired
concentration
Dangers of barbiturates
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Extremely large doses can be fatal
Cause paralysis in brain centers that
regulate breathing
Stimulants
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Drugs that produce feelings of energy and
activation
Amphetamines and cocaine
Inhibit reuptake of dopamine and
norepinepherines; neurons continue to fire
long after they should’ve stopped firing
Raise BP, heart rate, and respiration
More about stimulants
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Yield short periods (20-40 minutes) of
pleasurable sensations
Users then “crash” and experience anxiety,
depression, and fatigue
Cocaine and Crack
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Cocaine is usually snorted, but it can also be
swallowed (produces weaker effects that way)
Crack: cocaine that’s been heated and treated
chemically; can be smoked, which produces
immediate effects—powerful high, burst of
energy, confidence, excitement
Cocaine isn’t considered technically addictive,
but it can create psychological dependence
Opiates
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Opium, morphine, heroin, and related synthetic
drugs
Morphine comes from opium; heroin comes from
morphine
Produce lethargy, slowing down of almost all
bodily functions
Alter consciousness, produce a dreamlike state &
intensely pleasurable sensations
Extremely addicting; withdrawal is agony. Brain
stops producing endorphins. Physical addiction
occurs very quickly.
Psychedelics/hallucinogens
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Drugs that alter sensory perception
LSD, marijuana, ecstasy
Marijuana
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Most common psychedelic
Dates back to 2500 BC, at least
Could be found in drugstores as late as the 1920s,
purchased without prescription
Produces moderate effects—increased heart rate,
changes in BP, dilation of blood vessels in eyes
(bloodshot eyes)
Heightened sense of sight, sound, creative ideas
More about marijuana
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Causes inability to carry out tasks
involving attention & memory or to judge
distances
Reduced inhibitions, feelings of relaxation
or drowsiness, increased hunger & sexual
pleasure
Cultural factors influence what the user
experiences
LSD
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Results in profound changes in perceptions of the
external world
Objects and people seem to change color and
shape, walls may move, and sensations seem
more intense than normal.
May cause paranoia and intense fear of friends
and relatives
Extremely dangerous; can result in permanent
mental illness
Ecstasy
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Also known as MDMA
A so-called “designer drug” that’s both a
stimulant and mild hallucinogen
Triggers release of dopamine, but its main effect
is to release stored serotonin & block its
reabsorption.
Increases awareness of emotions, changes visual
perceptions, produces feelings of closeness to
others.
Dangers of Ecstasy
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Used by up to 40% of today’s teenagers
Prolonged use leads to confusion, fatigue, nausea,
and depression (because it reduces serotonin
levels)
Interferes with sleep, suppresses immune system,
impairs memory & cognitive functions
Can result in date rape or other unwanted sexual
encounters