Miller comparator hypothisis Flashcards
What is the assumption of Miller?
Stimuli and context acquire associative strength - independently from each other - with the CS
Learning rule: non-competitive!
Based on contiguity
All associations are excitatory
How to the different stimuli gain associative strength?
Conditioned behavior through a CS is a function of a comparative process:
Associative strength target CS
Associative strength comparator stimuli
Contextual and other discrete CS during trial
How does a excitatory or inhibitory RESPONSE happen?
The amount of excitatory / inhibitory response =
a function from the comparison between the associative value of the target and comparator stimuli.
Excitatory value of target CS > is more than > excitatory value comparator stimuli = excitatory response
Excitatory value target CS is less than excitatory value comparator stimuli = inhibitory response
What are the 3 TYPES of association comparator hypothisis?
Target CS – US association (link1)
Target CS – Comparator Stimuli association (link2)
Comparator Stimuli – US associatie (link3)
There will be direct and indirect activation of the US representation
Comparison direct and indirect association values > determines CR
response
What is the type of hypothesis?
Comparitor hypothesis is a ‘ performance explanation’ not a learning theory
How does overshadowing work?
Not because association X-US is weaker!!!
But amount of comparator stimuli = context + CS A
is bigger during XA+ training,
than if its only X+ (where only the context is the comparator stimuli)
How is blocking done?
CR on X smaller after A+ training followed by XA+ training than with XA+ training without prior A+ training
Not because relationship X-US is not learned as well.
But because in the blocking group the comparator stimulus A has developed a bigger associative strength through the A+ training - than in the control - with no prior A+ training
Predictions of post-acquisition manipulation of comparator stimuli (A OR CONTEXT)
Can not be explained with traditional learning theory!
Retrospective revaluation = shown by Miller
Post-acquisition extinction of context
prediction: extinction of context will lead to stronger CR - conditioned response on target A
This has been shown experimentally!
Can not be explained by R-W model and other models!
Unblocking / unovershadowing
Phase 1: A+ training
Phase 2: XA+ training
Less response to X than if you directly would do XA+ training in phase 1.
cause: comparator A - for target X - is stronger in blocking group.
Prediction: extinction of A will lead to increase or appearance of CR of the blocked target X.
Experimentally proven!!
extinction of inhibition
after creating negative contingence X-US:
Strength of comparator stimuli for X (A & context, or context) bigger than strength target X, dus “inhibition response” to X
prediction: extinction of comparator stimuli will lead to disappearance of inhibition (or to light excitatory response) to X
Experimentally proven!!
backward blocking
XA+ training
Followed by
A+ training
Prediction: comparator A for target X should become stronger.
So CR to X should become weaker or less = “backward blocking”
Experimentally proven!!
Does post-acquisition strengthening of context work?
prediction: strengthening context will lead to weaker CR to target A
NOT PROVEN WELL
