Transcript 5.1 Classical Conditioningx

Unit 5 Lesson 1: Classical Conditioning
What is Learning?
Learning: (relatively) permanent change in behavior due to
experience
Associative learning: learning that certain events occur
together
• 2 types – classical conditioning & operant conditioning
Ivan Pavlov
• Originally a medical researcher
• Made his discovery about learning
while researching digestive systems
• Realized dogs began to salivate
when they saw/smelled food
• Began to pair the food with a
neutral stimulus (bell)
• Wanted to see if the dogs would
link the neutral stimulus to the food
over time and get the same
response (salivate)
Conditioning
Trial
Salivation
Classical Conditioning:
learning where a neutral
stimulus is paired with an
unconditioned stimulus (US)
and elicits a conditioned
response (CR)
Test
Trial
Salivation
I. Elements of Associative Learning
• Unconditioned Stimulus (US): a stimulus that has the ability to produce a specific
response before conditioning begins
• Pavlov example: the food
• Unconditioned Response (UR): a response produced by a natural stimulus
• Pavlov example: salivating at the food
• Conditioned Stimulus (CS): an initially neutral stimulus (NS) that comes to
produce a new response because it is associated with the US
• During this stage acquisition (initial stage of learning, neutral stimulus
becomes associated w/ US) occurs
• Pavlov example: the bell
• Conditioned Response (CR): the response produced by the CS
• Pavlov example: salivating when hearing the bell
Let’s practice!
US
Jim offering a mint to Dwight
UR
Dwight reaching his hand out
CS
Sound of computer restarting
CR
Dwight reaching his hand out
I. The Elements of Associative Learning
a. Extinction
After conditioning has taken place, repeatedly presenting
the CS (bell) w/o the US (meat) will make the CR (salivating)
weaker & eventually make it disappear.
I. The Elements of Associative Learning
b. Reconditioning
relearning of a conditioned response after extinction
with only 1 or 2 more pairings (CS with US).
Extinct
Response
1 or 2
CS-US
pairings
Conditioned
Response
I. The Elements of Associative Learning
c. Spontaneous Recovery
Following extinction, the CR reappears at reduced
strength if the CS is presented again after a rest
period.
Extinct
Response
Time
- days-
Conditioned
Response
I. The Elements of Associative Learning
d. Stimulus Generalization
After a CR has been trained to a CS, that same CR will tend
to occur to similar stimuli w/o further training. The greater
the similarity, the stronger the response will be.
- Can lead to phobias
e. Discrimination
Act of responding differently to stimuli that are not similar
US: dog bite (pain from bite)
UR: fear – trying to escape
CS: sight of that dog
CR: fear of dog
Generalization: fear of all dogs
Discrimination: doesn’t fear stuffed
animal dogs
I. The Elements of Associative Learning
f. Conditions in Classical Conditioning
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Timing - closer in time = more effective
Predictability - pairing of US & CS is consistent
Signal Strength - Strength of CS is strong
Attention - the amount of attention that is directed at
the CS