6.2 Conditioned Inhibition Flashcards
What does extinction as inhibition mean?
Extinction creates new inhibitory association that counteracts original association
What is inhibitory learning?
This is when the presence of the US is more likely when the CS is absent
What is a -ve contingency?
Presenting the US only when the CS is absent
What is a summation test?
Inhibitory CS reduces responding to another CS+
Idea that if you have conditioned inhibitor CS, if you present it with another excitatory CS at the same time = reduction in conditioned responding relative to excitatory CS presented on its own
What is a retardation test?
If a CS is inhibitory and then subsequently pair that with a US, the learning for the subsequent inhibitory CS-US pairing is impaired
This is relative to a novel CS
How does the R-W model explain inhibition?
A = excitatory CS, X = conditioned inhibitor CS
Where there is no US, lambda = 0
V decreases from 1 for CS A (excitatory)
For V of CS X, the V value is less than 0 - This explains X-no US association
Discuss R-W model predictions when a CS A is reinforced 100% and CS B has partial rft of 50%?
Learning occurs faster and reaches higher asymptote for CS A
What happens when you present a new CS with a partially reinforced 50% CS B followed by no US?
Animals quickly learn to expect no US due to the conditioned inhibitor
How do we work out the associative strength of the inhibitory stimulus?
Conceptually, should expect the conditioned inhibitor (CI) to have equal magnitude to CS but in -ve direction
CI brings the CR back to baseline so needs to have the same magnitude in opposite direction in order to cancel this out
Discuss what happens when you use conditioned inhibitors during the process of extinction
1st conditioning group : Form B->US association and then form B inhibitory association
Set up as an extinction so responding should reduce to B
○ Responding decreases to B at test alone
What happens if you present B followed by non-reinforcement alongside X?
X is a conditioned inhibitor
B in the 2nd condition, at test alone, responding is higher because animals have learnt the combo of X and B = inhibitory conditioning
X protects B from extinction in this condition
What are real-life implications of CI and extinction?
E.g. bully on the bus scenario
Getting bullied on the bus but when your older sister is there no bullying
Older sister = conditioned inhibitor
Someone tells the teacher that the bully is bullying and the bully stops in general
You still catch the bus with older sister - don’t have the opp to learn the bully has stopped in general
Attribute the lack of bullying to the conditioned inhibitor
According to R-W, what should happen when an inhibitory CS is repeatedly presented on its own without the US?
Due to (0–V) delta V is +ve, so V increases up towards 0
i.e take a CI (-V) and present it on its own without any US: R-W predicts extinction of inhibition - we know this DOES NOT HAPPEN and CI’s do not extinguish
What does the R-W model predict should happen when an inhibitory CS (X) is repeatedly presented with a neutral CS (Y) and no US?
DeltaV is positive for both X and Y
On the 1st trial, lambda = 0, there will be -ve V
Delta V will be +ve due to prediction error for both X and Y
Will end up extinguishing X and Y has an increase in associative strength above 0 suggesting that you have learnt something about Y and the US that X is inhibiting
Even tho never presented Y with the US at all - this doesn’t make sense
This is another failure of the R-W model
What is the psychological content of inhibition?
Different types of associative connection:
excitatory link primes memory of US
inhibitory link suppresses memory of US
Different view is that there is an excitatory association between CS and “no US” rather than inhibitory association
