DREAMING p'18797

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DREAMING p.187/97

• Nature of dreams
• Functions of dreams
• Neurobiological theories
• Psychological theories

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FACTS ABOUT DREAMS

• Most dreaming takes place in REM.
• 700 hours per year are spent dreaming, so it must
  have an important function.
• It is not observed in dolphins or spiny anteaters
  (mammals), nor in fish, reptiles and amphibians.

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TIME SPENT DREAMING

• Newborns 9hours per night
• Adults 2 hours per night
• We forget 95 of our dreams
• An EOG is used to measure
• eye activity and therefore
• dreaming.

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A STUDY OF DREAMING

• Complete an APFCC on DEMENT AND KLEITMANs
  pioneer study on dreaming.
• If REM sleep is dream sleep, we would expect the
  eye movements to be related to the visual imagery

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3 TYPES OF DREAM THEORY

• Neurobiological Psychological
• Activation synthesis Wish fulfilment
• Reverse learning Problem solving

Evolutionary Survival strategy
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ACTIVATION-SYNTHESIS P.189(Hobson and McCarley
77)

• They worked from the fact that the brain is as
  active during REM as when we are awake.
• They proposed that high levels of activity in
  certain parts of the brain (areas concerned with
  perception, action and emotions) during sleep
  were randomly produced by neural firing in those
  areas.

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BUT

• Body movement is inhibited, so dreamers interpret
  signals as being external rather than internally
  generated.
• The dreamer attempts to synthesise the
  information contained in the neural activity
  bursts.
• Hobson believed that the brain is so motivated to
  find meaning that it creates meaning even though
  there is none.

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EVIDENCE FOR ACTIVATION SYNTHESIS THEORY

• HOBSON 88 found random firing of brain cells in
  cats during REM.
• He also found evidence to show how internal
  events are interpreted as external

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EVIDENCE FOR ACTIVATION-SYNTHESIS

• Levels of neurotransmitters (noradrenaline and
  serotonin) are lower in REM. (This clashes with
  restoration theory). Reduced levels prevent
  brain from organising information coherently. So
  the brain misinterprets.
• This may also explain why we forget our dreams,
  because attentional processes are aided by
  neurotransmitters.

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EVALUATION

• Task find evaluations on p.190
• 1. Based on detailed research fo brain
  physiology
• 2. Explains why smell and taste do not enter
  dreams
• (these areas are not activated)
• 3. Explains incoherent nature of dreams, if
  activity
• is random and attentional processes are not
• functioning)
• - 4. Some dreams do seem to have clear meaning
  and
• coherence
• - 5. It cannot explain why dreams repeat or are
• related to present concerns
• - 6. Analyses REM activity, but dreams also occur
  in NREM

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REVERSE LEARNING THEORY
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REVERSE LEARNING THEORYCrick and Mitchison

• The main function of dreaming is to get rid of
  useless information stored in the brain
  (parasitic information)
• This uses up valuable space in the cortex by
  overloading the neural networks. Dreaming
  eliminates unimportant information and allows
  neural networks to function more efficiently.

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AN ACCIDENTAL BY-PRODUCT

• BLAKEMORE proposed that the brainstem bombards
  the cortex with impulses, so unwanted material is
  unlearned by modifying the sypnapses.
• Dreaming is therefore seen as an accidental
  by-product of a neurobiological process.
• A-S theory also views it
• in this way.

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EVALUATION

• Theory is hard to test, because how can you find
  out if something has been forgotten?
• CRICK AND MITCHISON looked at size of cortex of
  different mammals. Suggested that dolphins and
  spiny anteaters have very large cortexes so they
  dont need to eliminate material
• BUT
• The human brain is much
• more folded and so has
• a larger capacity.

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AN ALTERNATIVE EXPLANATION

• WINSON 77 suggested that dolphins and spiny
  anteaters have a larger cortex so that they can
  eliminate information and process incoming
  information at the same time (when awake). This
  is why they dont have REM sleep.

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EVALUATION OF REV. LEARNING THEORY

• 1. It explains why we dont remember much of our
  dreams (95 is forgotten)
• 2. It does not explain why dreams are sometimes
  meaningful and significant.
• 3. Foetuses have a sort of REM. Yet they have
  nothing to unlearn. REM may establish trial
  neural pathways.
• 4. Connectionist theories propose that the brain
  is so vast that there is no need to save space.

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PSYCHOLOGICAL THEORIESWISH FULFILLMENT

• Freud 1900 proposed that dreams represent the
  wish fulfilment of repressed desires. He created
  this theory by analysing his own dreams.
• Irma, one of his patients, was not recovering
  with his treatment. In a dream, he saw another
  doctor using a dirty syringe on Irma. He
  interpreted his dream as taking the blame away
  from himself, i.e. wish fulfilment.

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MANIFEST AND LATENT CONTENT

• Manifest content what we dream
• Latent content the true meaning
• of the
  dream
• We dream in symbols because our wishes are
  unacceptable to us.
• Dream analysis aims to work out the symbolic
  meaning of dreams.

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FREUDIAN SYMBOLS
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EVIDENCE

• HAJEK AND BELCHER 91 studied dreams of smokers
  who were trying to give up. Ps reported dreams
  about smoking for up to a year after.
• Those who dreamt a lot about this, and suffered
  guilt feelings in their dreams were less likely
  to start smoking again.

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EVALUATION OF WISH FULFILLMENT THEORY

• TASK find evaluations of this theory p.192
• 1. This was the first systematic theory of dream
  function.
• 2. Freud argued that dreams can provide us with
  information about the unconscious.
• 3. Activation synthesis theory claims that
  there is a quest for meaning. This theory
  focuses on that aspect.
• 4. It does not explain nightmares.

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PROBLEM SOLVING THEORYWebb and Cartwright

• Kekule solved the atomic structure of the benzene
  ring in a dream, when he dreamt of a ring of
  snakes
• WEBB AND CARTWRIGHT the purpose of dreaming is
  to solve problems of work, health, sex and
  relationships etc. So, like W.F. it is a way of
  coping with problems. Dreams express current
  concerns. They deal with desires, but also with
  fears.

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PROBLEM SOLVING THEORY

• Like WF theory, it proposes that we dream in
  metaphor, e.g. falling off a cliff failure in
  exams.
• But manifest content is taken more literally than
  in WF theory.

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EVIDENCE FOR PS THEORY

• Webb and Cartwright study in which Ps were
  given problems to solve, then allowed to sleep.
  Some Ps were woken before REM sleep.
• Those Ps who were deprived of REM sleep were
  less able to provide realistic solutions to
  problems. This suggests that REM helps solve
  problems.

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INVESTIGATION

• Cartwright interviewed women undergoing a
  divorce. He compared 3 groups
• 1 2 3
• Divorcing Divorcing Married
• and and not and not
• depressed depressed depressed
• All 29 Ps were studied over 6 nights in a sleep
  lab.

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FINDINGS

• Group 2 reported longer dreams than group 1.
  Dreams dealt with marital issues.
• Group 1 did not report that they were dreaming of
  marital issues. So depression may have been
  associated with inability to deal with problems,
  even in dreaming
• HARTMANN found that people who were experiencing
  problems had more REM sleep

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EVALUATION OF PROBLEM SOLVING THEORY

• Theory has face validity
• Not all dreams seem
• to be related to
• problems
• It does not explain why
• we forget so much of
• our dreaming.

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WINSON proposed that REM is an
information processing period. The days events
are integrated with past memories to form a
strategy for survival, i.e. improve our survival
tactics

• SURVIVAL STRATEGY THEORY

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EVIDENCE FOR SURVIVAL STRATEGY THEORY

• Support for this comes from the fact that people
  deprived of REM find it hard to remember key
  events of the previous day.

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WHY SLEEP HELPS SURVIVAL

• Also, our body movements are inhibited because
  otherwise we would act out our dreams and
  possibly hurt ourselves. Eye movement does not
  interfere with sleeping.