Download Classical conditioning (Pavolv)

Classical conditioning
(Pavlov – 1899, 1927)
Pavlov’s original
experiments
• Pavlov was measuring the amount of
saliva produced by dogs when they ate.
• He found that the sight or sound of the
lab technician feeding the dogs also
produced salivation.
• Salivation had become associated with
a new stimulus (the technician) and not
just the original stimulus (food).
Key Terms
• Classical conditioning
– Refers to a form of learning that occurs through the repeated
association of two (or more) different stimuli.
– Learning is only said to have occurred when a particular
stimulus consistently produces a response that it did not
previously produce.
• Stimulus
– Any event that elicits (produces) a response from an
organism (eg, food)
• Response
– A reaction by an organism to a stimulus (eg, salivation)
• Conditioned reflex
– An automatic response that occurs as the result of previous
experience.
Unconditioned stimulus
(UCS)
• Any stimulus which produces an
unconditioned response (UCR).
– Food (UCS) causes salivation (UCR)
Unconditioned response
(UCR)
• The response which occurs
automatically as a result of the
unconditioned stimulus (UCS).
• A reflexive, or involuntary, response is
an UCR as it is predictably caused by
an unconditioned stimulus (UCS).
– Dogs salivate (UCR) at food (UCS)
Conditioned stimulus (CS)
• The stimulus which is ‘neutral’ at the
start of classical conditioning and does
not normally produce the unconditioned
response (UCR) but eventually
becomes associated with the
unconditioned stimulus (UCS).
– Sound of bell causes no response
– Sound of bell (CS) after being “paired” with
food (UCS) produces saliva (UCR)
Conditioned response (CR)
• The learned or acquired response to the
conditioned stimulus.
– The sound of the bell (CS) leads to
salivation (CR) without the food (UCS)
Process of acquisition
• The overall process during which the
organism learns to associate two events
(the CS and the UCS).
Stimulus discrimination
• The ability to distinguish between two
(or more) different stimuli, even if the
stimuli are similar.
Stimulus generalisation
• The tendency for similar stimuli to
produce the same, but not necessarily
identical, response.
Extinction and Recovery
• Process of extinction The gradual
decrease in the strength or rate of a CR
that occurs when the UCS is no longer
presented.
• Spontaneous recovery: The
reappearance of a conditioned
response after its apparent extinction.
Real-life application
• Some animal
training such as
hand signals or
clickers
• Aversion therapy
– one-trial learning