5.1 Models of Associative Learning

Question 1

What were the 3 very important associative learning findings published in the same year?

Answer 1

Kamin: blocking
Rescorla: contingency demonstration with truly random design
Wagner: signal validity

Question 2

What did the 3 findings lead to?

Answer 2

A paradigm shift in how we thought about conditioning

Previously, had been dominated by S-R theory and behaviourists

Now, it was important to understand how conditioning actually occurs

Question 3

When do we get good learning?

Answer 3

When a CS is a valid predictor of the US over and above the other CS’s present

Question 4

What is the basic idea behind signal validity?

Answer 4

Learning which is the best predictor of the aversive stimulus

Question 5

Describe the 3 groups in 1st experiment on signal validity (before it was better controlled)

Answer 5

3 groups association with the tone is equated
Each group has a TL pairing and followed by a shock

Group 1: T+L –> US
similar to overshadowing

Group 2: T+L –> US, L–> US
In addition, intermixed throughout conditioning, you will get light paired with shock as well as TL + shock
Similar to blocking

Group 3: T+L –> US, L–> nothing
In addition, intermixed throughout conditioning, you will get light paired with nothing as well as TL + shock

Question 6

What was the signal validity experiment observing?

Answer 6

The conditioned response to the tone and to see how the animals differed in their response depending on the conditioning phase

Question 7

What were the results for group 2 (blocking)?

Answer 7

Similar to blocking:

Weak conditioning
Teaches that the light is the valid predictor of the shock, not the tone
Tone doesn’t add much in terms of signal validity in this case

Question 8

What were the results for group 3 (L–> nothing) ?

Answer 8

Very good conditioning to the tone

Learn that light is a poor signal of US because it is paired with nothing
Tone is learned as a valid signal predictor of the shock

Question 9

What was wrong with Wagner’s first experiment on signal validity?

Answer 9

It was not perfectly controlled - the animals may habituate to the shocks

Question 10

What did Wagner change in the second experiment to make it better controlled?

Answer 10

Used correlated and uncorrelated groups

Everything was made the same other than what was being investigated

T1 and T2 were diff pitches so the animals could discriminate

Question 11

Describe the correlated group

Answer 11

T1 + L–> US
T2 + L –> nothing

Light is sometimes followed by shock, sometimes not

Tones are correlated with the outcome:
T1 = shock, T2 = nothing

Question 12

Describe the uncorrelated group

Answer 12

T1 + L –> US/nothing (50/50 chance)
T2 + L –> US/nothing (50/50)

Tones are not correlated with either outcome - there is a 50% chance of getting US or nothing

Question 13

On testing all 3 CS’s (T1, T2, L), what was found for the correlated group?

Answer 13

High conditioning to T1 and low to T2

Supports signal validity

Question 14

On testing all 3 CS’s (T1, T2, L), what was found for the uncorrelated group?

Answer 14

T1 and T2 found to have little conditioning occur

L has the highest result as being the best signal predictor

Question 15

Why is L the best signal predictor in the uncorrelated group?

Answer 15

This is the key demonstration of signal validity:

The light is present more often when the shock is presented and this is what makes it stand out and, relatively speaking, makes it become a more valid signal of the shock

Can still have learning to a cue when it is partially reinforced - this is what is going on with the light
It is partially reinforced greater than the other tones and this is why it is learned better

Question 16

What are the 2 classes of theories that can explain variation in attention to CS?

Answer 16

Mackintosh argument: conditioning can be explained due to diffs in the amount of attention that is allocated to the CS

Kamin: learning being modulated by how the US is processed (Rescorla-Wagner model)

Question 17

What was the Mackintosh argument?

Answer 17

Variations in conditioning reflect variations in attention to CS

Attention is a limited resource
We need to be able to allocate our attention towards specific events in the environment
In doing so, it takes away from other things we can give our attention to in the environment

We get conditioning because we attend to certain things in the environment = selective attention

Question 18

How does attention variation explain overshadowing?

Answer 18

Variations occur when a CS is v salient e.g. loud noise captures our attention a lot - v intuitive

Don’t get much learning to the light that is paired with it because of overshadowing

When something is more salient, we pay more attention to it and so learn more readily about the cue

Question 19

How does attention variation explain signal validity?

Answer 19

More important signals capture attention better than less important signals

Will give more attention to the valid predictor and devote less attention to the ones that are bad signal predictors

Question 20

How does attention variation explain blocking?

Answer 20

Attention is allocated to salient, good predictors - use this to explain blocking:

Throughout the pre-conditioning phase, learnt that noise is a v good predictor of US
As a result, this increases your attention to the noise

2nd conditioning phase - because you have learnt that the noise is a good predictor, its (signal validity) salience has increased relative to the light

Focusing attention on noise over light - no attention paid to the light even if equally matched in physical salience

Question 21

Why do variations in conditioning occur according to Kamin?

Answer 21

Learning is being modulated by how the US is processed - animals won’t learn anything on a trial in which all the events are fully expected

Learning is a process by which we revise what we know about the external world whenever our expectations differ from what actually happens

Question 22

How did Kamin explain his blocking results?

Answer 22

Explained in terms of surprise = you learn about something if it is surprising

Animal is forming a mental model of what happens in the world and when something is surprising and conflicts with your mental model, this is when you update the model and change your beliefs

Something occurs you don’t expect is when you update your representation of the world - it is to do with the processing of the US

Question 23

How has the notion of surprise been formalised into a simple model?

Answer 23

The Rescorla-Wagner model

It is a numerical equation capturing Kamin’s idea

Question 24

What does the R-W model describe?

Answer 24

Describes how animals learn associations between CS and US and how quickly the link is formed

Question 25

How is learning determined in the R-W model?

Answer 25

Learning is determined by the discrepancy between the experience of the US and how much it was expected

Question 26

What is the discrepancy in learning referred to in the R-W model?

Answer 26

The prediction error: (lamda - sigmaV)

Question 27

What is the difference between +ve prediction error and -ve prediction error?

Answer 27

+ve prediction error = when an event isn’t predicted by you and so learning occurs

-ve prediction error = over expecting something and you still get learning but it is reduced

Question 28

Define V

Answer 28

The amount you know

Everything you might predict

Question 29

Define lamda

Answer 29

The maximum amount of learning that is supported by the US

Question 30

Define sigma V

Answer 30

All that you know about all the CS’s present on that trial

How much association is there between the light and US as well as tone and US for example

Question 31

Define alpha

Answer 31

Salience of the CS

Question 32

Define beta

Answer 32

Salience of the US

Question 33

Define delta V

Answer 33

Change in V

i.e. change in the amount of learning