Classical Conditioning II
A. Generalization
1. CR occurs to stimuli similar
to the CS
•
even though these stimuli may
have never been associated
with the UCS
2. The more similar the stimuli
are to the CS, the greater
likelihood of generalization
– Ex: Pavlov’s dogs salivating at
a different tone than in training
John Watson and Generalization
• Little Albert
– sight of white rat (CS) was paired with loud
noise (UCS) until the CS alone produced
crying and other responses indicative of fear
• Ethical issues with Little Albert
– Never heard from again
– Failure to ensure no lasting ill effects
Results?
– Demonstration showed
human emotional
responses could
develop as a result of
classical conditioning
Generalization gradient
B. Discrimination
1. stimuli similar to the CS does not
produce a CR
2. The less similar new stimuli are to the
original CS, the greater the likelihood of
discrimination
•
What happens to generalization gradient
when an organism learns a discrimination?
How are discrimination and
generalization similar? Different?
C. Higher-Order Conditioning
1. A CS functions as if it were a UCS
•
Result: classical conditioning does not
depend on natural US (remember the
sexy quails?)
Higher-Order Conditioning
E. Factors that Affect Conditioning
1. Contiguity: The closer two stimuli are in space
and time, the stronger the association between
them.
------------------------------------------------------------------2. “Belongingness”: The “fit” between CS and US
3. Contingency: “Information value.” The higher
the correlation between two stimuli, the
stronger the conditioned response.
4. Salience: More intense or noticeable stimuli
condition more rapidly.
1. Contiguity model
•
•
Argues conditioning will occur whenever CS
and UCS are paired
Based on Pavlov
2. CS-US belongingness: not all CS’s and
US’ associable
3. Contingency model
• Argues CS must reliable predict UCS for
conditioning to occur
– based on work of Rescorla and Wagner (took
in-depth look at each trial of conditioning)
– Supported by phenomena like blocking
(Kamin)
• Multiple CS tests, results?
Contingency is a little like…
• Animals being scientists, trying to make
casual predictions
… trying to determine whether the
US is contingent on the CS
Contingency Phenomena
• US pre-exposure effect: Presenting the
US repeatedly prior to CS-US trials retards
acquisition.
• CS pre-exposure effect: Presenting the
CS repeatedly prior to CS-US trials retards
acquisition. (a.k.a. Latent Inhibition)
Leon Kamin: Blocking
• US has to be “surprising” for association to
occur
– Selective attention and learning
4. Salience effects
• Overshadowing – in compound or higher
order conditioning, the more salient CS
wins
One last one… d’oh
• Test devaluation: critical period when
stimulus/response has occurred too much,
creating an adverse effect
In Conclusion!!
2 models
1. Contiguity
•
Conditioning will occur when CS and UCS are
paired
2. Contingency
•
CS must reliably predict UCS for conditioning to
occur (there are a lot of things that could get in
the way of that)