States of Consciousness

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States of Consciousness

• Consciousness is not necessarily a state that is
  fully distinct from unconsciousness.
  
• Its meaning we know so long as no one asks us to
  define it.
  
• William James

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Consciousness

• Consciousness The subjective experience of
  perceiving ones self and other entities.
  
• Decreased brain activity accompanies declines in
  level of consciousness
  
• Not all neurological activity is conscious
  though, (e.g., reflexes)

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Unconscious Processes

• The phenomenon of readiness potential the
  increased motor cortex activity prior to the
  start of a movement - provides evidence that we
  begin our actions before we become aware of our
  intention to act.

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Other Phenomena of Consciousness

• Deja vu is feeling of uncanny familiarity with a
  strange person, new place or event.
  
• Capgras syndrome is a condition in which person
  insists that familiar individuals are actually
  impostors who resemble those people

5
Circadian Rhythms

• Circadian rhythms are cycles of activity and
  inactivity generally lasting about one day (from
  the Latin circa about and dies day.)
  
• Most peoples circadian rhythms, when allowed to
  occur in an environment free of familiar time
  cues (like living in a cave for several months)
  stabilize at a little over 24 hours.

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Circadian Rhythms

• Are you are morning person, or an evening
  person?
  
• Most young adults are evening people, or
  neutral.
  
• Most people over the age of 65 are morning
  people.
  
• This difference is even found in performance
  differences in laboratory rats (Winocur Hasher,
  1999.)

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Figure 10.7

• Figure 10.7 If tested early in the morning,
  older persons perform as well as younger people
  on memory tasks. As the day progresses, young
  people improve and older people deteriorate.

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Circadian Rhythms

• Shifting sleep schedules
• Mechanisms in the brain rely on light to reset
  your bodys clock and keep it in step with the
  environment.
  
• If you travel between time zones you will be out
  of step for a while.
  
• Jet lag is the period of weariness and discomfort
  that occurs while your body clock adjusts to your
  new time zone. It is easier to adjust going east
  to west than west to east.

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Figure 10.8

• Figure 10.8 People traveling east suffer more
  serious jet lag than people traveling west.

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Circadian Rhythms

• Brain mechanisms
• The circadian cycle of sleep and wakeful states
  is governed by the suprachiasmic nucleus
  (SCN.)
  
• This tiny structure at the base of the brain is
  essentially your bodys clock.
  
• The SCN controls the sleep-wake cycle in part by
  regulating the secretion of the hormone melatonin
  by the pineal gland.

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Figure 10.10

• Figure 10.10 The suprachiasmatic nucleus, a small
  area at the base of the brain, produces the
  circadian rhythm. Information from the optic
  nerves resets the circadian rhythm but is not
  necessary for its generation.

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Why Do We Sleep?

• Several benefits
• Sleep saves energy
• Mammals and birds lower their body temperature.
• Animals decrease muscle activity.
• People conserve energy in times of famine by
  sleeping longer and lowering their body
  temperature.

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Why Do We Sleep?

• Evolutionary theory Animals have evolved to only
  sleep as much as is safe and doesnt interfere
  with their needs (birds dont sleep during
  migration)
• Lions sleep about 20 hours a day while gazelles
  sleep much less.
  
• Gazelles are on the menu for lions. They need
  more time to eat, and must run away quickly.
  

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Stages of Sleep

• The discovery of REM
• REM
• rapid-eye movement sleepers eyes move rapidly
  around under the closed eyelids.
  
• paradoxical sleep
• large muscles of the sleeper are so relaxed that
  the person is effectively paralyzed

15
Stages of Sleep

• REM and dreaming
• People tend to report vivid dreams when awakened
  during REM sleep.
  
• complex dreams have also been reported during
  non-REM sleep, especially the Stage II that
  occurs at the end of the night.
  
• Researchers are now questioning the close
  association of REM sleep with dreaming.

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Stages of Sleep

• Sleep cycles during the night
• Researchers use an electroencephalograph (EEG), a
  machine that measures electrical activity on the
  scalp that is associated with activity in the
  brain combined with a device to measure eye
  movements.

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Stages of Sleep

• NREM stages
• When first dozing off, the sleeper enters Stage 1
  NREM.
  
• There is little eye movement, and a fair amount
  of brain activity (desynchronized activity.)
  
• Stage 2 NREM follows, in which a gradual
  transition begins into the synchronized, slow
  wave states.

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Stages of Sleep

• NREM stages
• Stages 3 and 4 NREM feature long, slow
  synchronized waves.
  
• These waves indicate decreased brain activity.

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Stages of Sleep

• Pattern of stages across the night
• This first episode of REM ends the first cycle of
  the night.
  
• A healthy adult has 90-100 minute sleep cycles
  all during the night.
  
• After the first cycle, REM replaces stage 1.
• Stages 3 and 4 decrease during the night.
• The last sleep cycles of the night are usually
  comprised of alternations between stage 2 and REM.

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Stages of Sleep

• Patterns of dreaming
• Adults report dreams 85-90 (REM) and 50-60
  (NREM) of the time on awakening.
  
• Adults who claimed that they dont dream report
  dreams when awakened during REM in a sleep
  laboratory.
  
• Children
• Dreams follow REM in length 1 minute of REM
  produces a brief dream, longer periods produce
  more complex dream stories.

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Stages of Sleep

• The functions of REM sleep
• When people are deprived of only REM sleep, their
  brains will produce more and more of it.
  
• They will also become quite irritable, anxious
  and distracted.
  
• People deprived of REM sleep will experience a
  rebound when finally allowed to indulge.

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Stages of Sleep

• The functions of REM sleep
• Over the life cycle, patterns of REM sleep
  change.
  
• Infants get more REM sleep than children, and
  children get more than adults.

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Abnormalities of Sleep

• Insomnia
• Insomnia means lack of sleep. It is hard to
  define insomnia by number of hours because
  theres a wide range of normal sleep lengths.
  
• Insomnia is better defined by complaints of
  feeling poorly rested due to lack of sleep.
  
• Many adults have occasional insomnia.
• Serious or chronic insomnia is often associated
  with medical or psychological disorders such as
  depression.

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Abnormalities of Sleep

• Sleep apnea
• One possible cause of insomnia is sleep apnea.
• People with sleep apnea may fail to breathe for a
  minute or longer, and wake up gasping for breath,
  or die.
  
• Snoring is closely associated with this
  disorder.
  
• Many sufferers from sleep apnea are obese
  middle-aged or elderly men.
  
• Other cases of sleep apnea are associated with
  abnormalities in the medulla (brainstem).

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Abnormalities of Sleep

• Narcolepsy
• Sudden attacks of extreme and irresistible
  sleepiness during the day is known as
  narcolepsy.
  
• Associated with these attacks are muscle weakness
  or paralysis and vivid dreams.
  
• It is as if they are having a sudden burst of REM
  sleep in the middle of a waking period.

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Abnormalities of Sleep

• Parasomnias
• Other unsettling occurrences during sleep
  include
  
• Sleep talking, which is not a symptom of any
  psychological disorder.
  
• Sleep walking, usually found in children during
  stage 4 sleep. It is perfectly safe to wake a
  sleepwalker.

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Abnormalities of Sleep

• Parasomnias
• Other unsettling occurrences during sleep
  include
  
• Nightmares, or unpleasant dreams that are
  reported by almost everyone at some time.
  
• Night terrors, which involve awaking during
  slow-wave sleep in an extreme panic, more common
  in children than in adults.

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Abnormalities of Sleep

• Hypersomnia Too much sleep?
• Hypersomnia excessive sleep that is not
  refreshing.
  
• Otherwise there is no such thing as too much
  sleep.

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The Content of Our Dreams

• Freuds approach
• He referred to the surface content of the dream
  as manifest content.
  
• He called the hidden content, represented only in
  symbols latent content.

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The Content of Our Dreams

• Freuds approach
• The only way an analyst can discover the meaning
  of the latent content is to determine the
  dreamers personal associations to the details of
  the manifest content.
• But its not scientific there is no to be
  certain what a dream means, or to test this
  approach empirically.

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Theories of Dreaming

• The Activation-Synthesis theory
• This theory of dreams proposes that input from
  the brainstem (the pons) activates the brain
  during REM sleep.
  
• The cerebral cortex tries to make sense of the
  random activity by imposing a story on the
  stimuli that activate the sense organs during
  this process.

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Theories of Dreaming

• The Activation-Synthesis theory
• The meaning is not a cause, as in Freuds
  approach, but rather a by-product.
  
• This theory does not make clear, testable
  predictions any more than Freuds does.

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Theories of Dreaming

• The Neurocognitive theory
• This theory assumes that dreaming is thinking,
  occurring under special conditions.
  
• The conditions include persistent activity of
  the cortex, reduction of sensory stimulation, and
  loss of self-control of thinking.
  
• REM is not necessary for dreaming, but the
  emotional arousal created by REM tends to
  intensify dreams.

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Theories of Dreaming

• The Neurocognitive theory Evidence
• Dreaming seems to require some degree of
  cognitive maturity (dreams are rarely reported by
  children under 5.)
  
• The stronger the imagination of the person when
  awake, the greater the chance of dreaming.
  
• There are common dream themes in the United
  States usually these are concerned with anxiety
  and things going wrong.

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Hypnosis

• What is hypnosis?
• Hypnosis (from the word Hypnos, the name of the
  Greek God of sleep) is a condition of increased
  suggestibility that occurs in the context of a
  special hypnotist-subject relationship.
• But it is not the same as sleep. Hypnotized
  people can respond to stimuli from the outside
  world.

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Hypnosis

• What is hypnosis?
• Hypnosis was first practiced by an Austrian
  philosopher and physician, Franz Anton Mesmer.
  
• He attributed his success at various treatment
  strategies (use of magnets and his own hands) as
  evidence of his own animal magnetism.
  
• In all likelihood, his subjects were responding
  to the power of suggestion.

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Hypnosis

• Ways of inducing hypnosis
• Hypnosis is a voluntary, cooperative social
  interaction
  
• There are no special powers required to be a
  hypnotist.
  
• No one can hypnotize an uncooperative person.
• Believing that one is hypnotized is a big step
  towards actually being in a state of hypnosis.

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Hypnosis

• Uses and limitations of hypnosis
• Hypnosis can produce
• Increased relaxation
• Better concentration
• Temporary changes in behavior that sometimes
  persist beyond the end of the hypnotic state
  
• It will NOT give a person new mental or physical
  abilities.

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Hypnosis

• Uses and limitations of hypnosis
• A well-established use of hypnosis is to help a
  person control and manage pain.
  
• Some people can undergo dental or medical
  procedures with hypnosis alone.
  
• This is a very helpful ability for those who have
  unfavorable reactions to anesthetic drugs or who
  have developed a tolerance to painkillers.

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Hypnosis

• Uses and limitation of hypnosis
• Pain has both sensory and emotional components.
• For a hypnotized person, the emotional reaction
  is altered. The sensory portions of the brain are
  stimulated, as is the case for a person who has
  not been hypnotized, but the emotional portions
  are unresponsive.

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Figure 10.17

• Figure 10.17 A hypnotic suggestion to experience
  less pain decreases activity in the frontal
  cortex areas associated with emotional distress
  but has little
• effect on the sensory areas in the parietal
  cortex.