Blocking

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Blocking
Prior conditioning to one element of a compound
reduces (blocks) learning to other elements.
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Pretraining to A reduced learning to B
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Kamin Memory Scan Hypothesis Active memory
search only when US is surprising
Blocking Contiguity not sufficient. Must be
surprising US.
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Psychonomic Bulletin Review, 1996
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Related to US Magnitude
CR
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Maximum amount of learning related to US
Magnitude
Vmax
CR
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Recall Learning only when US is surprising
(Kamin)
So, Learning on a given trial µ Surprise
Define Surprise ?
Surprise Get - Expect
Putting it together. Learning on a given trial
µ Get -Expect Change in learning µ US what
you learned so far
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Maximum amount of learning related to US
Magnitude
Vmax
GET
Surprise Get - Expect
Vmax V
CR
Change in associative strength on a given trial
?V
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Different rates of aquisition
Rate parameter, c, related to salience of the
CS 0 c 1
?V c (Vmax - V)
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2 Parameters (mathematical constants) Vmax (US
amplitude) c (CS salience) These are
estimated Can make qualitative, not quantitative
predictions
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Why is the CR eliminated during Extinction ?
Pavlov Extinction build up of inhibition
CS
R-W Loss of Associative Strength (V)
R
US