Transcript Classical Conditioning

Classical Conditioning
Learning
What is it?
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The process through which a response previously made only to
a specific stimulus is made to another stimulus that has been
paired repeatedly with the original stimulus.
Ivan Pavlov’s dog experiment--stimuli & responses
 Unconditioned response (UCR)= response that is elicited by
a stimulus without prior learning.
 Ex: Mouth watering (when dog sees/smells food)
 Unconditioned stimulus (UCS)= stimulus that elicits a
specific response without prior learning.
 Ex: Food (makes dog’s mouth water)
 Conditioned stimulus (CS)= neutral stimulus that, after
repeated pairing with an UCS, become associated with it &
elicits a conditioned response.
 Ex: Bell paired with food (makes dog’s mouth water)
 Conditioned Response (CR)= response that comes to be
elicited by a conditioned stimulus as a result of its repeated
pairing with an unconditioned stimulus.
 Ex: Mouth waters when hear a bell (that had been
paired with food)
Extinction, Spontaneous Recovery,
Generalization & Discrimination
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Extinction= Weakening & disappearance of a learned
response due to repeated presentation of the CS without
the UCS
 Ex: Hear bell, no food appears
Spontaneous Discovery= Reappearance of an extinguished
response when an organism is exposed to the original
conditioning stimulus following a rest period
 Ex: Hear bell, given food again
Generalization= Tendency to make a CR to a stimulus
similar to the original conditioned stimulus
 Ex: Mouth waters when hear a telephone ring (similar
to a bell)
Discrimination= Learned ability to distinguish between
similar stimuli so that the CR occurs only to the original
conditioning stimulus but not to similar stimuli
 Ex: Baby calls all men daddy, until she realizes she only
gets a positive response from one man
John Watson
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“Little Albert”
 John Watson sought to prove that fear can be classically
conditioned
 When Albert reached for a white rat (that he liked to play with),
Watson struck a steel bar with a hammer near Albert’s head
 The sound made Albert jump, fall forward and whimper
 Watson continued to pair the rat with the loud noise
 Eventually Albert began to cry at the sight of the rat alone
 UCS = loud noise
 UCR= jump, fall, whimper
 NS = white rat
 CS = white rat
 CR = cry
 Albert’s fear was generalized to a white bunny, and somewhat
less to Watson’s hair and a Santa mask
 Conclusion: conditioned fears “persist and modify personality”
John Watson
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Peter
 How can you remove conditioned fears?
 Peter = afraid of white rats, fur coat, feathers, cotton, fur rug
 Watson and Mary Cover Jones gave Peter food he liked, brought
white rabbit into room
 Over the course of 38 therapy sessions, the rabbis was brought
closer to Peter, who continued to enjoy his cookies
 Peter’s friends brought in to play with the rabbit—Peter sees that
the rabbit is not a threat
 Eventually, the rabbit is put into Peter’s lap as he ate and Peter
liked it!
 Fear is gone
Everyday Conditioning
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Example of neutral cue that has become associated with people,
objects, or situations and develop the power to elicit the same
feeling as the original stimulus in YOUR life.
 Example: Sarah McLachlan’s Angel makes me cry because it
was played at my grandma’s funeral
Factors Influencing Classical Conditioning
 Number (#) of pairings of the CS and the UCS
(greater
# = stronger CR).
 Intensity of the UCS (stronger UCS paired with CS, then CR
will be stronger and faster).
 How reliably the CS predicts the UCS.
 Ex: Bell that’s always followed by food will cause more
salivation.
 Temporal relationship between the CS and the UCS. (ideal
time =1/2 second)