From Behaviourism to Cognitive Psychology

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From Behaviourism to Cognitive Psychology
www.neuro.spc.org/rawnsley
Vaughan Bell vaughan_at_backspace.org
Outline

• Philosophy and Roots of Behaviourism
• Classical Conditioning and Operant Conditioning
• Relationship to Psychopathology
• Learned Helplessness and Depression
• Latent Inhibition and Schizophrenia
• Decline of Behaviourism and the rise of Cognitive
  Psychology.

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Behaviourist Philosophy

• Behaviourism arose out of a desire to make the
  understanding of human behaviour more objective,
  and to move away from techniques such as
  introspection which were considered unscientific.
• James Watson argued in his 1914 book Behavior
  An Introduction to Comparative Psychology that
  behaviourist principles could explain all of
  human behavior without any reference to mental
  events such as desires, goals or inner thoughts.
• These were considered to be mere metaphors or
  illusions.
• B.F. Skinner, in his novel Walden Two, went as
  far as to propose that society should organised
  along behavourist lines.

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Roots of Behaviourism

• In the early part of the 20th century scientists
  such as Ivan Pavlov and Edward Thorndike were
  researching animal learning.
• Pavlov was working on the physiology of the
  digestive system in dogs and discovered
  salivation could be induced by the sound of a
  bell if it had previously been presented with
  food.
• This is called classical conditioning and
  involves the pairing of a stimulus which already
  elicits a response, with a stimulus which
  initially doesnt.
• After conditioning both stimuli will elicit the
  same response.

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Classical Conditioning
Initially there may be a Unconditioned Response
(UCR) to a Unconditioned Stimulus (UCS).
UCR
UCS
salivation
food
The UCS can be presented with an arbitrary
Conditioned Stimulus (CS).
CS
bell
UCR

salivation
UCS
food
Which causes the arbitrary CS to elicit a
Conditioned Response (CR).
CR
CS
salivation
bell
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Classical Conditioning

• It is interesting to note that similar principles
  work on the level of a single neuron.
• Donald Hebb, a Canadian neurophysiologist,
  discovered principles now called Hebbian
  Learning.
• One of which was that connections between neurons
  will be strengthened if they fire simultaneously.
• In other words, when two events occur
  simultaneously they become associated, even at
  the neural level.

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Operant Conditioning

• About the same time, Thorndike was interested in
  trial and error learning and tested animals on
  their ability to escape from specially prepared
  boxes.
• He discovered that levers were more likely to be
  pressed on a second occasion if a reward (escape)
  followed.
• This is know as positive reinforcement.
• The organism is encouraged to produce a behaviour
  because of a reward that follows.

positive reinforcer
followed by
behaviour
lever press
escape
encourages
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Operant Conditioning
Punishment is another process which can be used
to reduce the occurrence of behaviour.
punishment
followed by
behaviour
talking in cinema
ice down back
discourages
Negative reinforcement is a process whereby
previously presented unpleasant stimuli are
removed in order to reinforce a behaviour.
followed by
behaviour
negative reinforcer
quiet in class
no homework
encourages
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Extinction

• Extinction is when a learnt association between
  two stimuli is weakened because one is presented
  without the other.
• For example, in Pavlovs experiment, if the bell
  was sounded enough times, and no food appeared,
  then the bell would eventually cease to illicit
  salivation.
• This is the basis of techniques for treating
  phobias such as flooding or systematic
  desensitisation.
• Phobia inducing stimuli are presented until the
  anxiety subsides, extinguishing the association
  between stimulus (e.g. spider) and response
  (anxiety).

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Relationship to Psychopathology

• Watson believed that mental illness was the
  result of habit distortion caused by learning
  of inappropriate associations.
• He tested this by inducing mild phobia in little
  Albert.
• Albert was presented with a tame rat, which he
  played with quite happily.
• On a second occasion the rat was paired with a
  loud noise (striking of a large steel bar behind
  Alberts head), causing anxiety when the rat was
  presented on further occasions.

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Learned Helplessness and Depression

• Seligman (1975) was experimenting on dogs,
  pairing tones with electric shocks.
• They prevented the dogs from escaping from the
  shock, and discovered that after a while 65 of
  the dogs did not try to escape when either the
  tone or shock was given.
• Seligman argued that the dogs had learned
  helplessness
• He argued that depression was a form of learned
  helplessness, in effect a conditioned response.
• It was argued that depressed people had learned
  that whatever they did was futile, and they had
  no control over their lives.

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Criticism of Learned Helplessness and Depression

• This theory was criticised as it was pointed out
  that helpless people do not necessarily become
  depressed.
• It doesnt seem to explain the guilt and self
  blame many depressed people feel (Carson Adams,
  1981).
• How can you feel guilty about things you have no
  control over ?
• The theory was reformulated to include
  attribution.
• Attributions were supposedly internal ("it's my
  fault"), stable ("things can't change"), and
  global (this affects everything).
• However, research has shown that depression tends
  to correlate with external locus of control.
• And there is no evidence that these are causal
  effects.

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Schizophrenia and Latent Inhibition

• This is the principle whereby pre-exposure to a
  stimulus reduces the rate of learning when a
  reinforcer is paired with it at a later point.

CS
bell
UCR
CS

salivation
bell
UCS
pre-exposure
food
reduced
CR
CS
salivation
bell
learning
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Schizophrenia and Latent Inhibition

• Schizophrenics do not seem to show this effect.
• They learn stimulus pairing better than normal
  controls.
• It is argued that this is the result of a
  reduction in the influence of the regularities
  of past experience on current perception
  (Hemsley, 1987)
• Or, an inability to inhibit previously
  encountered stimuli, so all stimuli are treated
  as novel.
• However, behaviourism cannot fully explain these
  results, we have to think about them in terms of
  an information processing model.

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Decline of Behaviourism

• Whilst the behaviourists uncovered some important
  psychological principles it became obvious that
  behaviourism could not provide a complete account
  of human behaviour.
• Noam Chomsky demonstrated that language could not
  purely be the result of stimulus-response
  associations
• Children do not experience enough language
  stimuli to learn vocabulary and grammar as
  behaviourists might expect.
• Language is a discrete combinatorial system, in
  that we can create unique sentences that are
  comprehensible to other speakers despite them
  being entirely novel.

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Rise of Cognitive Psychology

• With these objections it became clear that it was
  impossible to ignore mental events in the
  understanding of human behaviour.
• the world of experience is produced by the man
  who experiences it - Neisser (1967)
• Cognitive Psychology takes an information
  processing view of mental processes.
• It allows us to empirically discover systems and
  processes that are involved in understanding and
  acting upon the world.
• As well as to produce models and map our
  understanding onto neural processes.