6.1 Extinction

Question 1

What happens when the CS is no longer paired with the US?

Answer 1

Extinction - the conditioned response (CR) stops

Question 2

What does the R-W model assume the value of lambda is for non-reinforcement?

Answer 2

0

Question 3

What happens according to the R-W model, when the CS is presented without the US?

Answer 3

It generates a -ve discrepancy (US is expected but absent)

Lambda = 0, sigmaV = 1 
(0-1) = error term

Question 4

When the CS is presented without the US, what happens to deltaV and V?

Answer 4

DeltaV is -ve and V begins to decrease

Question 5

Why does lambda normally equal 1 in examples?

Answer 5

Due to convenience and ease of the model

Question 6

How do you work out the true value of lambda when presented with a graph?

Answer 6

Find the asymptote
e.g. if asymptote = 17, then lambda = 17

We take the value of 1 in examples for convenience

Question 7

Does the R-W model predict extinction?

Answer 7

Yes

Learning (V) decreases as CS-US pairing is extinguished

Question 8

What is a partial reinforcement schedule?

Answer 8

The CS and the US are not always followed by each other - only partially reinforced

Under reinforcement schedule of 100% - every time CS is presented, followed by US

Under partial rft schedule of 50% - on 50% of time CS is presented, followed by US

Question 9

Does the R-W model predict partial reinforcement schedules well?

Answer 9

Yes - the way it accounts for it is similar to extinction

Question 10

Explain how the R-W model predicts partial reinforcement learning

Answer 10

R-W predicts a reduction in associative strength similar to extinction when the CS is not always followed by the US - this is because deltaV is -ve

Partial reinforcement schedules show a lower asymptote for learning

Question 11

What does the R-W model predict for different learning schedules when they are being extinguished?

Answer 11

It predicts the highest asymptote takes the longest to decrease (i.e. continuous takes longer than partial because 100% is higher than 50%).

This is incorrect

Question 12

What is the partial reinforcement effect?

Answer 12

Using a partial reinforcement schedule results in resistance to extinction - the R-W model does not account for this

Question 13

How does the R-W model explain extinction and what are the 3 contradictions of this?

Answer 13

Explains it as unlearning the CS-US pairing, as if we are erasing the link

However, there are conditions that produce a recovery in responding following extinction:

Spontaneous recovery
Rapid reacquisition
Renewal and reinstatement of responding

Question 14

What is spontaneous recovery?

Answer 14

Responding recovers to the CS simply by the passage of time

Question 15

What is rapid reacquisition?

Answer 15

After extinction, conditioned responding to the CS is reacquired faster than before

Demonstrates that the CS-US link has not been completely erased

Question 16

What is renewal?

Answer 16

After extinction of responding in one context, responding can be renewed if the CS is presented in a different context

Question 17

What are the 3 different groups in the experiment that shows evidence for renewal?

Answer 17

All groups get conditioning of CS-US pairing in context A

Group 1: CS is extinguished in context A
Group 2: CS is extinguished in context B
Group 3: no extinction but presented in context B (control)

The groups are then tested in context A

Question 18

What are the results for the different groups in the renewal experiment?

Answer 18

Group 1 are less scared of CS as it was extinguished in the context it is being tested in

Group 2 show a renewal of the fear to CS when tested in context A - CS was extinguished in B

Control still show fear as never underwent extinction

Question 19

Discuss a flaw in exposure therapy related to extinction and renewal

Answer 19

Exposure therapy happens in the context of clinical setting and reductions in fear happen well

But when you go back to the real world, the context is diff and fear may not decrease

Good to do exposure therapy in diff environments to avoid renewal

Question 20

What is reinstatement?

Answer 20

After extinction, responding can be reinstated if the US is presented alone

Question 21

What is the explanation for extinction referring to “masking”?

Answer 21

Extinction is masking the original learning such that there are still some scenarios where original learning will dominate

Question 22

How does Bouton explain extinction?

Answer 22

Bouton suggests animals acquire multiple memories of the CS

After conditioning, only memory is CS –> US

After extinction, animals have 2 different memories with conflicting content:

1. memory of CS –> US
2. memory of CS alone

CR is determined by which type of memory is retrieved on test

Question 23

What is the key difference between Bouton’s explanation for extinction and the R-W model?

Answer 23

R-W model thinks of a single link between CS-US

Bouton thinks of 2 different associations: CS-US that strengthens and CS-US that weakens

Question 24

What do animals use to decide which memory to retrieve (Bouton)?

Answer 24

Temporal and physical cues

Question 25

Are memories from extinction episodes situation specific according to Bouton?

Answer 25

Yes - animal retrieves memories when tested in similar situation, but fails to retrieve them in different contexts or after a long time

This is why spontaneous recovery, renewal and reinstatement can occur