Learning

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Learning

• A relatively permanent change in an organisms
  behavior due to experience
• How does learning occur?
• through associations
• (Classical Conditioning)
• through outcomes
• (Operant Conditioning)
• though observation
• (Observational Learning)

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Non-associative learningthe simplest form of
learning.
The simplest form of learning. The response to
a repeated stimulus will decline
across repetitions. A form of non-associative
learning, it involves only one stimulus.

• Habituation
• The response to a repeated stimulus will decline
  across repetitions.

• Sensitization
• The response to an important stimulus will
  increase for a while.

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Classical Conditioning

• first studied by
• Ivan Pavlov (1849-1936)
• two stimuli close together allow a response to
  transfer from one to the other
• Pavlovs explanation excitatory links form
  between centres in the brain this process
  occures automatically.

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Salivary Conditioning Apparatus
... how to ask the right question ....
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Classical conditioning

• Unconditioned Stimulus (UCS or US)
• Unconditioned Response (UCR or UR)
• Conditioned Stimulus (CS)
• Conditioned Response (CR)

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Pavlovs Work

• Before Conditioning
• During Conditioning After Conditioning
• The neutral stimulus (the tone) becomes a CS
  through association

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How long does it last?

• Extinction
• Elimination of a learned response by removal of
  the unconditioned stimulus
• Spontaneous Recovery
• Re-emergence of an extinguished conditioned
  response after a rest period

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Generalization

• Response Generalization
• The tendency to respond to a stimulus that is
  somewhat similar to the conditioned stimulus

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Discrimination

• Stimulus Discrimination
• The ability to distinguish between different
  stimuli

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Real-Life Examples

• Conditioned Taste Aversion
• a taste (CS) associated with a toxin (US) leads
  to nausea (UR)
• later, the taste alone evokes nausea (CR)

Biological restraints
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Rats are sensitive to taste

Birds to sight
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• Drug Tolerance
• tolerance is specific to specific environments
  (e.g. bedroom)
• taking drug in unfamiliar environment leads to
  lack of tolerance

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phobias
dangerous stimulus associated with neutral one
results fear from the later
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Little Albert
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Instrumental or Operant Conditioning

• - involves stimuli with
• motivational significance
• the consequences of
• behaviors influence the
• likelihood of their being
• repeated
• far more flexible than classical
• conditioning, can give rise to novel responses.

B. F. Skinner
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Skinner-box
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Trial and error
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The dog gets time to find the lever

• .

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Operant Conditioning

• for Classical Conditioning
• expectations are important
• for Operant Conditioning
• outcomes are important

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Thorndikes Law of Effect

• Behaviors that
• have pleasurable consequences tend to be
• repeated under similar circumstances
• Good consequence? Do it again!
• Bad consequence? Dont do it again!

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Schedules of Reinforcement

• Rate at which a reinforcer is delivered
• influences the nature of response(s)
• Continuous Reinforcement
• reinforcing the desired response each time it
  occurs
• (rapid learning, rapid extinction)

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• Partial Reinforcement
• reinforcing a response only part of the time
• results in slower acquisition, greater
  resistance to extinction
• Partial Reinforcement Schedules
• Ratio schedule
• Fixed ratio
• Variable ratio

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Fixed ratio

• Reward after a fixed number of responses (people
  being paid on a "commission)

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Variable ratio

• Reward after an unpredictable number of responses
• (inserting coins and pulling the handle of a
  "one-armed bandit.)

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Interval schedule

• Fixed interval Reward after a specified length
  of time from the last reinforcement (checking
  your mail in the mailbox)

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Interval schedule

• Variable interval
• Reward for first response after
• a variable amount of time
• (pressing the "redial" button
• when there is a "busy" signal on the other end of
  the line.)

(electronic mail)
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Reinforcement
Punishment
Positive
Negative
Negative
Positive
Stimulus is ...
Stimulus is ...
Stimulus is ...
Stimulus is ...
Presented
Removed
Presented
Removed
Behavior..
Behavior...
Behavior...
Behavior...
Increases
Increases
Decreases
Decreases
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Reinforcement Punishment
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Punishment

• decreases likelihood of behavior happening
  again, because the consequence is not good
• Positive Punishment
• Negative Punishment

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Problems with Punishment

• Punished behavior is not forgotten, it's
  suppressed
• behavior returns when punishment is no longer
  eminent
• Physical Punishment Linked to Increased
  Aggression
• shows that aggression is a way to cope with
  problems
• Creates fear that can generalize to desirable
  behaviors, e.g. fear of school, learned
  helplessness, depression
• Does not necessarily guide toward desired
  behavior
• reinforcement tells you what to do,
• - punishment tells you what not to do

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Operant Conditioning Concepts

• Shaping
• Reducing complex behaviors into several more
  simple behaviors
• Reinforcing successive approximations to the
  complex behavior

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Escape-learning

• when meeting a dangerous stimulus

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Avoidance learning

• Beware of phobias!

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COGNITIVE APPROACHES
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Observational Learning
Albert Bandura. Bobo Doll Study

• occurs when an organisms responding is
• influenced by the observation of others (models).
• Children watched a film of a women being
  aggressive towards a Bobo doll. In the playground
  the children imitated the women in the film
  acted aggressively towards the bobo doll

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Cognitive-Social Theory
Cognitive maps in rats men (Edward Tolman 1948)

• mental representations
• images

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Latent learning

• learning that has occurred but not currently
  manifested in behavior

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Cognitive-Social Learning
Learned Helplessnes (Seligman, 1975)

• the expectancy that one cannot escape aversive
  events
• motivational learning deficits result from the
  belief.

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Human depression
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Learning by insight

• Kohlers classic experiment
• The animal mind
• Chimp (Sultan) and bananas

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• Mental trial-and error

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Smart ravens