Chapter 5 States of Consciousness

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Chapter 5States of Consciousness
2
States of Consciousness

• Consciousness is not necessarily a state that is
  fully distinct from unconsciousness.
• There are varying degrees of consciousness.
• It is a very fascinating topic to contemplate and
  discuss.
• It is a very difficult topic to investigate.
• Its meaning we know so long as no one asks us to
  define it.
• William James

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Module 5.1

• Sleep and Dreams

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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.
• Your degree of alertness depends where you are in
  your circadian rhythm.

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Circadian Rhythms

• Are you are morning person, or an evening person?
• Human beings seem to fall on a continuum morning
  people, evening people, or no distinct
  preference.
• Where you fall on the continuum seems to have a
  relationship to age.
• 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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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, the light in
  your new location will eventually reset your
  clock, but you will be out of step for a while.
• Jet lag is the period of weariness and discomfort
  that occurs while your body clock is out of step
  with your new time zone. It is easier to adjust
  going east to west than west to east.

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• Figure 5.3 People traveling east suffer more
  serious jet lag than people traveling west.

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Circadian Rhythms

• Shifting sleep schedules
• Staying up late on the weekends (if this is not
  ones usual habit) can produce a jet lag type
  feeling on Monday morning Monday morning brain
  fog.
• Shift work, a necessity in many industries, poses
  a similar problem. Working graveyard and
  rotating shifts are particularly difficult.
• Being awake at times when ones body is used to
  being asleep can be hazardous to ones health
  (due to lapses in judgment and slowness of
  reflexes).

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• Figure 5.4 The graveyard shift is aptly
  namedserious industrial accidents usually occur
  at night, when workers are least alert.
  Night-shift jobs providing emergency services are
  essential. But few people want to work
  permanently at night, so workers rotate among
  three shifts. As in jet lag, the direction of
  change is critical. Moving forwardclockwiseis
  easier than going backward.

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Circadian Rhythms

• Shifting sleep schedules
• Transferring rotating shift workers to later
  shifts has been found to be less stressful and
  harmful than transferring them to earlier shifts.
• Providing bright lights on the night shift can
  also ameliorate some of the harmful effects of
  being awake when the body clock is set for sleep.

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Concept Check

• If you are a Los Angeles based CEO, and you need
  meet with an executive from New Delhi, India to
  negotiate a tough deal, should you try to
  convince the executive in Europe or in Japan?

Japan It will be better for your energy level
and mental alertness, anyway.
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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 5.5 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. Cells in the
  suprachiasmatic nucleus can generate
  approximately a 24-hour rhythm of activity on
  their own, even if they are separated from the
  rest of the body.

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Why Do We Sleep?

• Two theories
• The repair and restoration theory of sleep
  proposed that the reason that we sleep is to
  allow the body time to recover from the exertions
  of the day.
• Evidence gathered from observing and recording
  the results of sleep deprivation support this
  theory.

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Why Do We Sleep?

• Two theories
• People who are sleep deprived tend to exhibit
  more frequent bouts of illness (due to immune
  system depression) and poor performance in work
  and tasks such as driving (due to impaired
  concentration.)
• However, all the restorative functions observed
  during sleep can take place during the awake
  state.
• We need to sleep no matter how active or inactive
  we have been during the day.
• So it is possible that there is more to sleep
  than restoration.

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Why Do We Sleep?

• Two theories
• The Evolutionary theory or Energy Conservation
  theory proposes that evolution has equipped all
  animals with a regular pattern of sleep and
  wakefulness to help us conserve energy and avoid
  dangers.
• This theory accounts well for differences among
  species.

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• Figure 5.7 Many birds sleep with one eye open,
  unless they are sitting next to another bird that
  might be keeping watch. Humans, too, sleep less
  well if they are in an unfamiliar or possibly
  dangerous place.

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Why Do We Sleep?

• Two theories
• Lions sleep about 20 hours a day while gazelles
  sleep much less.
• Lions, for example, are predators who can afford
  lots of sleep between sizable and rich meals.
• Gazelles, who need to graze on less nutrient-rich
  vegetative matter, and are on the menu at the
  lions favorite dining haunt, need more time to
  eat, and also need to run away at a moments
  notice.
• The lion and the calf shall lie down
  together, but the calf wont get much sleep.
  -- Woody Allen

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Why Do We Sleep?

• Two theories
• Both of these theories are probably correct to a
  large extent. They do not contradict each other,
  and they do a good job of explaining some of the
  reasons for and features of sleep in animals.
• Yet there are more mysteries to unravel in
  answering this question.

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Stages of Sleep

• The discovery of REM
• Sleep research was jump-started in the late
  1950s when researchers in the United States and
  France independently discovered REM activity
  during sleep.
• REM stands for rapid-eye movement because the
  sleepers eyes are moving rapidly around under
  the closed eyelids.
• It is also referred to as paradoxical sleep
  because there is physiological and brain wave
  activity almost indistinguishable from the waking
  state.
• Yet the large muscles of the sleeper are so
  relaxed that the person is effectively paralyzed.

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Stages of Sleep

• REM and dreaming
• People tend to report vivid dreams when awakened
  during REM sleep.
• But complex dreams have also been reported during
  non-REM sleep, especially the Stage II NREM sleep
  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.
• This combined machine is called a polysomnograph.
• It is used to track the changes in the sleepers
  states that occur across the night.

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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.
• The eyes remain relatively inactive during these
  slow-wave stages.
• The sleeper gradually moves back through stages 3
  and 2 and then has the first brief REM episode of
  the night.

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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 awakened during REM sleep report dreams
  85-90 of the time.
• Adults awakened during NREM sleep report dreams
  50-60 of the time.
• Adults who claimed that they dont dream report
  dreams when awakened during REM in a sleep
  laboratory.
• Children less than 5 years old rarely report any
  dreams.
• Dreams appear to follow REM in length 1 minute
  of REM produces a brief dream, longer periods are
  associated with more complex dream stories.

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Concept Check

• Are dream less likely to be reported towards the
  beginning or the end of the night?

The beginning There is proportionally less REM
sleep and brain activity during the first four
hours of the night.
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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.
• From these findings it is inferred that REM has
  some role in CNS development.

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• Figure 5.12 Newborns sleep alternates between
  wakefulness and naps throughout the day. Within a
  few months, infants consolidate most of their
  sleep into one longer period at night, although
  they continue having one or two naps during the
  day. As people grow older, the amount of sleep
  per day decreases. (Based on Kleitman, 1963)

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Stages of Sleep

• The functions of REM sleep
• Species that sleep more get more REM.
• Humans who sleep 9 hours or more get more REM
  sleep than those who sleep 6 hours or less.
• New research suggests that REM sleep may help to
  improve memory for difficult new tasks.
• It may also help to improve memory for motor
  skills.

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Stages of Sleep

• The functions of REM sleep
• This is not to say that the original purpose of
  REM was to help store memories for complex tasks.
  
• One speculation is that REM evolved to help
  oxygenate the delicate corneas during sleep.
• As computers were invented originally for
  mathematical calculation, and became much more
  diverse, so REM may also have acquired these more
  complex functions.

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Abnormalities of Sleep

• Insomnia
• The term insomnia means lack of sleep. It is
  hard to define insomnia by using numbers of hours
  because people vary in the amount of sleep that
  they need (from 5 to 10 or more.)
• If a person complains of feeling poorly rested
  due to not getting enough sleep, it is considered
  to be a complaint of insomnia.
• 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 men.
• These men are usually middle-aged or elderly.
• Other people who suffer from sleep apnea have
  been found to have abnormalities in the
  brainstem, specifically the medulla.

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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
  mental or emotional disorder.
• Sleep walking, usually found in children during
  stage 4 sleep. It is not the case that you
  should never wake a sleepwalker.
• Nightmares, or unpleasant dreams that are
  reported by almost everyone at one time or
  another.
• Night terrors, which involve awaking during
  slow-wave sleep in an extreme panic. These are
  common in children, less so in adults.

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Abnormalities of Sleep

• Leg movements while trying to sleep
• Prolonged crawly sensations in the legs,
  accompanied by strong repetitive leg movements
  that can wake the sleeper are part of a condition
  called periodic limb movement disorder (restless
  leg syndrome.)
• These symptoms usually occur during the first
  half of the night.
• This is a common cause of poor quality sleep in
  people over age 50.
• Caffeine, stress and fatigue are thought to
  exacerbate this condition.

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Abnormalities of Sleep

• Hypersomnia
• People vary in their need for sleep, there
  probably isnt such a thing as too much unless
• If a person reports excessive sleep that is
  unrefreshing, the condition is termed
  hypersomnia.
• A typical case would be a person who gets over 8
  hours a day during the week, and then needs to
  catch up by getting over 15 hours per day on
  the weekend.
• The person would still report feeling groggy,
  confused, and poorly rested.

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The Content of Our Dreams

• It was once believed that dreams foretold the
  future.
• But we now are certain that this is only by
  coincidence.
• The major controversy in psychology is whether or
  not the dream tells us anything about the
  dreamer.
• This is far from settled.

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The Content of Our Dreams

• Freuds approach
• Sigmund Freud, the founder of the psychoanalytic
  school, maintained that dreams reveal the
  dreamers unconscious thoughts and motivations.
• 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
• According to Freud, 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.
• This approach to dream analysis was very popular
  for many years.
• But we really have no reliable scientific way to
  be certain what a dream means, or to test this
  approach scientifically.

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Concept Check

• What would Sigmund Freud think of popular books
  that purport to interpret any readers dream
  symbols what pens, cars, or handbags mean to
  any dreamer?

Not much He believed that you needed to know the
dreamers associations to the content.
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Theories of Dreaming

• The Activation-Synthesis theory
• The activation-synthesis 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.
• Yet this theory does not make clear, testable
  predictions any more than Freuds does.

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Theories of Dreaming

• The Neurocognitive theory
• The neurocognitive theory assumes that dreams are
  a form of 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
• There is some interesting evidence for this
  perspective.
• 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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• Table 5.2 Stages in the development of dreaming
  in children

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Sleep

• Sleep research has allowed our scientific
  knowledge of consciousness to grow. Many
  interesting questions remain about the nature of
  sleep and the function of its stages, especially
  REM and the phenomenon of dreaming.

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Module 5.2

• Hypnosis

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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.

54
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 5.13 Hypnotic suggestions to experience
  less pain can decrease the emotional intensity
  but generally have less effect on the sensation
  itself. The hypnotic suggestion that a stimulus
  will not be unpleasant decreases activity in the
  frontal cortex areas associated with emotional
  distress but has little effect on the sensory
  cortex.

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Hypnosis

• Uses and limitations of hypnosis
• Another use of hypnosis is the posthypnotic
  suggestion
• A posthypnotic suggestion is a suggestion to do
  or experience something particular after coming
  out of hypnosis.
• Some treatments for addiction or bad habits that
  use repeated applications of posthypnotic
  suggestion have shown modest to moderate success.

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Hypnosis

• Uses and limitations of hypnosis
• Distortions of perception under hypnosis
• A few people report that they experience
  hallucinations (sensory experiences not
  corresponding to reality) under hypnosis,
  particularly haptic (touch) hallucinations.
• The brain areas involved in sensory processing
  were activated in some cases.
• On the other hand, hypnotized people who claim
  that they are NOT registering actual stimuli will
  show activity in the brain areas that process
  those stimuli.

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Hypnosis

• Uses and limitations of hypnosis
• Hypnosis cannot
• Give a person increased or special physical
  strength - anyone can do the things that people
  under hypnosis have been able to do.
• Enhance memory people under hypnosis are highly
  suggestible and memories recovered in this
  state are prone to be inaccurate and influenced
  by the agenda of the hypnotist.

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Hypnosis

• Uses and limitations of hypnosis
• Hypnosis increases confidence that recovered
  memories are accurate.
• Hypnotized people will perform some strange and
  risky acts. Although the evidence is limited by
  the fact that it is hard to find things that
  nonhypnotized people will refuse to do, it
  appears to be the case that people will not do
  anything under hypnosis that they arent really
  willing to do.

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Concept Check

• What are some practical uses of hypnosis?

Pain management Relaxation Increased
concentration
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Hypnosis

• Is hypnosis an altered state of consciousness?
• The debate concerning hypnosis is whether it is a
  special state of consciousness involving greatly
  increased suggestibility, or too similar to a
  normal waking state to be thought of as distinct
  from that state.
• Most psychologists are currently taking a middle
  ground on this issue.

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Hypnosis

• Is hypnosis an altered state of consciousness?
• How well can an unhypnotized person pretend to be
  hypnotized?
• Unhypnotized people can mimic most of the effects
  of hypnosis if they have been prepared.
• There are ways for observers to distinguish
  between those who have been hypnotized and those
  who are pretending.
• It seems that the effects that are mimicked by
  pretenders do happen spontaneously for hypnotized
  people.

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Concept Check

• Does hypnosis give people extraordinary or
  unusual powers?

No
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Hypnosis

• Meditation In some ways like hypnosis
• Meditation is a method of inducing a calm,
  relaxed state through the use of special
  techniques.
• It is a tradition that has been practiced in many
  world cultures for thousands of years.
• It has some similarities to the relaxed, passive
  state of hypnosis, but it requires no hypnotist
  or suggestions.
• Studies have documented that meditation can
  decrease physiological arousal, thus it is useful
  for relaxation training.
• As with hypnosis, it is important to try to
  separate truth from exaggerated claims when
  considering meditation.

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The Nature of Hypnosis

• A general consensus has yet to be reached on this
  topic, but agreement has been reached on certain
  points
• Hypnosis is not merely faking or pretending.
• It does not bestow any unusual abilities or
  powers.
• It does enable people to relax, concentrate and
  follow suggestions better than they otherwise
  would.
• Beware of any person who claims that it can do
  more than this.

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Module 5.3

• Drugs and their Effects

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The Survey of Abused Drugs and Their Effects

• The biological basis of drug abuse and addiction
• Nearly all abused and addictive drugs increase
  activity at the dopamine receptors in the brain.
• These drugs increase the release of dopamine,
  interfere with reuptake, and stimulate neurons
  that release dopamine or decrease activity of
  neurons that inhibit its release.

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The Survey of Abused Drugs and Their Effects

• The biological basis of drug abuse and addiction
• The addictive actions of dopamine particularly
  work upon a small brain area called the nucleus
  accumbens, a central area for attention and
  habit-formation.
• Activities such as gambling and video game
  playing can have the same biological effects.
• Addiction can be thought of as in the person, not
  in the drug.

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• Figure 5.18 The nucleus accumbens is a small
  brain area that is critical for the motivating
  effects of many experiences, including drugs,
  food, and sex. Most abused drugs increase the
  activity of dopamine, an inhibitory transmitter
  in this area. Other abused drugs, such as PCP,
  inhibit the activity of glutamate, an excitatory
  transmitter here. That is, a decrease in output
  by the nucleus accumbens is important for the
  effects of abused drugs and other motivating
  experiences.

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The Survey of Abused Drugs and Their Effects

• Stimulants
• Stimulants are drugs that boost energy, heighten
  alertness, increase activity and produce a
  pleasant feeling.
• Cocaine and amphetamine are examples of powerful
  stimulant drugs
• The net effect of cocaine is to decrease brain
  activity, which in turn stimulates behavior.
• Free-base and crack cocaine are forms that allow
  the drug to enter the nervous system more
  rapidly, thus producing a more powerful high.

72
The Survey of Abused Drugs and Their Effects

• Stimulants
• Ritalin, which is prescribed for children with
  ADD, is a strong but slow-acting stimulant.
• Caffeine, which is an ingredient in coffee, tea
  and many soft drinks, is a milder and less
  dangerous stimulant drug.
• Cigarettes are nicotine delivery devices.
  Nicotine is a powerfully addictive stimulant.
  Smoking is experienced as relaxing because
  between cigarettes the smoker begins to
  experience withdrawal, which a subsequent
  cigarette will temporarily alleviate.

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Concept Check

• If a person takes a drug that promotes the
  production and release of dopamine, how would the
  drug affect his or her response to cocaine?

It would probably enhance the effects of the
cocaine.
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The Survey of Abused Drugs and Their Effects

• Depressants
• Depressants are drugs that largely decrease
  physiological arousal.
• The most commonly used and abused depressants are
  alcohol and tranquilizers.
• These drugs work by facilitating the transmission
  of the neurotransmitter GABA.
• Alcohol is a class of chemicals including
  methanol, ethanol, and propyl (rubbing) alcohol.
• Ethanol is the type found in liquor, wine and
  beer.

75
The Survey of Abused Drugs and Their Effects

• Depressants - Alcohol
• Alcohol has been consumed in many world cultures
  for millennia.
• It acts primarily as a relaxant when consumed in
  small amounts.
• In greater amounts, it can increase aggressive
  and risk-taking behaviors.

76
The Survey of Abused Drugs and Their Effects

• Depressants - Alcohol
• Excessive consumption of alcohol can damage the
  liver and other internal organs.
• Excessive consumption of alcohol has been related
  to memory impairment and loss of motor control.
• Fetal alcohol syndrome, which can result when a
  pregnant woman consumes alcohol, is the number
  one preventable cause of mental retardation in
  the United States.

77
The Survey of Abused Drugs and Their Effects

• Depressants - Alcohol
• Alcohol abuse and dependence are worldwide public
  health problems.
• They are more common in some cultures than in
  others.
• Ethnic differences in alcohol consumption have
  been related to overall differences in lifespan.
  For example, the relatively greater rates of
  consumption among Native Americans and African
  Americans may constitute part of the reason for
  the shorter average lifespan in these populations.

78
The Survey of Abused Drugs and Their Effects

• Depressants Tranquilizers
• Medical doctors have prescribed tranquilizers in
  the past to help people relax and fall asleep.
• They have also been used to suppress epileptic
  seizures.
• Barbiturates, once a legitimately prescribed
  medication for these purposes, proved to be so
  addictive and dangerous that it is rarely
  prescribed today.
• Benzodiazepines, a class that includes drugs such
  as Valium, are milder drugs used for anxiety
  management. They are also highly addictive.

79
The Survey of Abused Drugs and Their Effects

• Narcotics
• Narcotics are drugs that produce drowsiness,
  insensitivity to pain, and overall decreased
  responsiveness to environmental stimuli.
• Opiates are one common type of narcotic.
• Opiates can be derived naturally from the opium
  poppy or synthesized in the laboratory.
• Opiates create a feeling of euphoria.
• Once the drug has been used up, the person begins
  to feel intense withdrawal and a need to use the
  drug again.

80
The Survey of Abused Drugs and Their Effects

• Narcotics
• Researchers have found that the human brain
  produces chemicals called endorphins.
• These neurotransmitters bind to opiate receptors
  and stimulate dopamine production.
• Neurons release endorphins when an individual
  experiences pain or stress.

81
The Survey of Abused Drugs and Their Effects

• Marijuana
• Marijuana is classified as a narcotic, but it
  intensifies sensory experiences and in many ways
  is not like the opiates.
• It has possible medical uses as a mild painkiller
  and nausea suppressant.
• It is a dangerous drug to use. As with tobacco,
  it poses a risk of lung cancer because it is
  usually smoked.

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The Survey of Abused Drugs and Their Effects

• Marijuana
• It appears to impair learning and memory. The
  active ingredient in marijuana, THC, is
  especially likely to attach to receptors in the
  hippocampus, where memories are consolidated.
• Because of the political overtones, research
  studies of marijuana have been tainted by the
  agenda of the researcher (pro or con) and may be
  unreliable.
• Marijuana is probably no more of a gateway drug
  than are tobacco and alcohol.

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The Survey of Abused Drugs and Their Effects

• Hallucinogens
• Drugs that induce sensory distortions and false
  sensory experiences are called hallucinogens.
• Peyote is an example of a naturally derived
  hallucinogen. It has played an important role in
  Native American religious ceremonies.
• LSD is a hallucinogen that is artificially
  manufactured. It works by altering serotonin
  receptors, but we are still unsure how this leads
  to altered sensory experiences.
• MDMA, also called ecstasy, acts as a stimulant at
  low doses and a hallucinogen at high doses. This
  hallucinogen appears to pose the greatest risk of
  brain damage to the user.

84
The Survey of Abused Drugs and Their Effects

• Chronic Drug Effects
• Initially a drug produces a pleasant effect.
• As it wears off, it produces an unpleasant
  effect, the opposite of how it made the user feel
  initially.
• These subsequent effects are referred to as
  withdrawal.

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The Survey of Abused Drugs and Their Effects

• Chronic Drug Effects
• As the user continues to take the drug, a
  decrease in effect, called tolerance develops.
• So even if the user consumes less of the drug,
  the unpleasant effects of withdrawal occur,
  motivating continued and increased use.

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The Survey of Abused Drugs and Their Effects

• Chronic Drug Effects
• When the user feels compelled to use chiefly to
  reduce the unpleasant withdrawal symptoms, the
  condition is referred to as physical dependence.
• This is usually distinguished from psychological
  dependence by the absence of the physical
  symptoms of withdrawal.

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The Survey of Abused Drugs and Their Effects

• Chronic Drug Effects
• For example, gambling appears to be addictive,
  but there is no accompanying withdrawal
  syndrome as there is with heroin or nicotine.
• But many psychologists believe that this
  distinction is pointless. Since even gambling has
  been shown to alter brain chemistry, the
  addiction is partly physically based. It is
  difficult to draw a clear line.

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The Survey of Abused Drugs and Their Effects

• Chronic Drug Effects
• What causes tolerance?
• It is still unclear, but seems to be related to a
  combination of changes in the body initiated in
  response to the drug (a reduction in the number
  of receptors, for example) combined with a
  gradual acclimation to functioning with the drug
  in the system (Wenger et al., 1981.)

89

• Table 5.3a Commonly Abused Drugs and Their Effects

90

• Table 5.3b Commonly Abused Drugs and Their Effects

91
Psychoactive Drugs

• Giving drugs to human beings can produce
  desirable or undesirable effects. These effects
  are very easy to understand and they give us
  greater insight into how the brains processes
  manufacture consciousness.

92
Psychoactive Drugs

• Altered states are not vastly different than
  normal states of consciousness. Dreaming appears
  to be a form of thinking, hypnosis is a
  volitional state and produces only mild effects,
  and drugs alter behavior in fairly predictable
  ways despite variations in the personality of the
  user.
• Even when your consciousness changes, you remain
  in essence yourself.