Download Conditioned Stimulus

CHS AP Psychology
Unit 6: Learning (Behaviorism)
Essential Task 5.2: Describe basic classical
conditioning phenomena with specific attention to
unconditioned
• stimulus, unconditioned response, neutral stimulus,
pairing, acquisition, conditioned stimulus,
conditioned response, extinction, spontaneous
recovery, stimulus generalization, stimulus
discrimination, contingency, and higher-order
learning.
Classical Conditioning
Book definition: The type of learning in
which a response naturally elicited by
one stimulus becomes to be elicited by
a different formally neutral stimulus.
Working definition:
• Type of learning that happens TO
someone
• Person learns to respond
BIOLOGICALLY to a stimulus.
• Previously the stimulus meant
nothing.
• Now it means something IS ABOUT
TO HAPPEN.
Examples of Classical
Conditioning
Phobias
After the attacks, cats become a
warning stimulus for pain causing
fear when the child sees cats.
After this botched photo, 6 ft
bunny becomes warning stimulus
for someone trying to capture
you.
Examples of Classical
Conditioning
Taste Aversion
After throwing up a
food, it becomes a
warning stimulus for
getting sick.
Key People
• Ivan Pavlov: Russian physiologist known primarily
for his work in classical conditioning.
Key People
• John B. Watson
Key People
• John Garcia
Unconditioned Stimulus (UCS)
• A stimulus that invariably causes an
organism to responds BIOLOGICALLY in
a specific way
Unconditioned response
(UCR)
• A BIOLOGICAL response that takes
place in an organism whenever an
unconditioned stimulus occurs
Neutral Stimulus
• A stimulus that does not naturally
cause a response in the organism.
Pairing
• Presenting the organism with the CS
and then the UCS multiple times.
+
=
Acquisition
• refers to the first stages of learning
when a response is established.
– In classical conditioning, it refers to the
period of time when the stimulus comes to
evoke the conditioned response.
– The time in between the two stimuli should
be about half a second.
Conditioned Stimulus (CS)
• An originally neutral stimulus that is
paired with an unconditioned
stimulus an eventually produces
the desired response in an
organism when presented alone.
Conditioned Response (CR)
• After conditioning, the response an
organism produces when only a
conditioned stimulus is presented.
Taste Aversion:
Single Conditioning
Experience
Stimulus Generalization
• the transfer of a learned response to
different but similar stimulus.
Stimulus Discrimination
• learning to respond to only one
stimulus and to inhibit the response to
all other stimuli.
Extinction
• Extinction is a decrease in the strength
or frequency of a learned response
because of no longer pairing the US
and CS
Spontaneous Recovery
• reappearance of an extinguished
response after the passage of time,
without further conditioning
Question of the Day
• Researchers condition a flatworm to
contract when exposed to light by
repeatedly pairing it with electric shock.
The electric shock is a(n)
A) negative reinforcer
B) conditioned stimulus
C) conditioned reinforcer
D) unconditioned stimulus
Contingency Theory of Classical
Conditioning
For Pavlov, the key variable in associative
learning was the number of times the CS was
paired with the US.
The Pairings Principle:
As the number of pairings increases, the
strength of the association between CS and
US increases.
This was because the CS became a more
reliable signal that the US was going to
occur.
Contingency Theory of Classical
Conditioning
• In the 1960s, an alternative theory was proposed
by Robert A. Rescorla, the Contingency Theory.
• Rescorla agreed with Pavlov that for learning
to take place, the CS had to be a useful
predictor of the US.
• But he disagreed on what made the CS a
useful predictor. It was more complicated
than the number of CS-US pairings.
He maintained that it was the contingency OR
THE CONNECTION between the CS and US.
Higher Order Learning in
Classical Conditioning
• Also known as second order
conditioning.
• A form of learning in which a stimulus is
first made meaningful or consequential
for an organism through an initial step
of learning, and then that stimulus is
used as a basis for learning about some
new stimulus.
– For example, an animal might first learn to
associate a bell with food (first-order
conditioning), but then learn to associate
a light with the bell (second-order
conditioning).