ClassicalPavlovian Conditioning

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Classical/Pavlovian Conditioning
Acquisition and Extinction
If extinction is not the unlearning of an
association, what is it?
The best answer would seem to be that extinction
training results in the suppression of a learned
association
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Classical/Pavlovian Conditioning
Little Albert
- early behaviorist study by Watson Raynor
- classic demonstration of learned fear
- also demonstrates the principle of stimulus
generalization
- this study would never pass ethical review today
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Classical/Pavlovian Conditioning
Discrimination and Generalization
Discrimination can a rat learn that a yellow
light means a shock will be delivered, but an
orange light does not? (i.e., is the distinction
between yellow and orange perceived by rats?)
Drug discrimination studies often used to assess
drug effects
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Classical/Pavlovian Conditioning
Discrimination and Generalization
Generalization If a CR is acquired to a
particular CS, will similar CSs also elicit a CR?
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Classical/Pavlovian Conditioning
Discrimination and Generalization
After conditioning, the CS alone elicits a CR
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Classical/Pavlovian Conditioning
Discrimination and Generalization
What about CSs of other colours?
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Classical/Pavlovian Conditioning
Discrimination and Generalization
Maximal CR seen in response to CS
Reduced CR seen in response to other stimuli (the
more similar to the CS, the bigger the CR)
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Classical/Pavlovian Conditioning
Biological Predispositions
Many early theorists assumed that all stimuli
were equally associable
There is evidence, however, that some CS-US
associations are formed more easily than others
E.g., taste aversion learning
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Classical/Pavlovian Conditioning
Taste aversion learning
Many organisms, including humans, are predisposed
to associate tastes with gastrointestinal illness
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Classical/Pavlovian Conditioning
Taste aversion learning
There is an obvious adaptive advantage to the
predisposition to associate tastes with
gastrointestinal illness, as these illnesses are
far more likely to be the result of something we
ate than something we saw, heard, etc
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Operant/Instrumental Conditioning
Where classical conditioning involves the
association of 2 stimuli (CS and US), operant
conditioning involves the association of a
response with an outcome
e.g., driving fast ? speeding ticket
Note that the subject is not passive here, as is
the case in classical conditioning
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Operant/Instrumental Conditioning
Thorndikes Law of Effect
If an action has pleasant consequences, the
probability that the action will be repeated
increases if an action has unpleasant
consequences, the probability that the action
will be repeated decreases
Based on observations of cats in puzzle box
Incremental modification of behavior
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Operant/Instrumental Conditioning
Skinner and the Operant Chamber
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Operant/Instrumental Conditioning
Skinner and the Operant Chamber
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Operant/Instrumental Conditioning
Skinner and the Operant Chamber
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Operant/Instrumental Conditioning
Skinner and the Operant Chamber
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Operant/Instrumental Conditioning
Shaping
Many responses you might wish to reinforce are
not already in the repertoire of the subject
(e.g., lever pressing in rats)
The subjects behavior can be shaped through the
use of successive approximations of the desired
behavior
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Operant/Instrumental Conditioning
Types of Reinforcement
Type of Stimulus
Appetitive
Aversive
Present it
Positive Reinforcement
Positive Punishment
What you do
Remove it
Negative Punishment
Negative Reinforcement