LECTURES 21 - 34

Question 1

QUANTITATIVE THEORIES

Answer 1

Equations that describe the relationship between behaviour and environment

Question 2

What four things can happen on a trial (i.e. after CS presentation)

Answer 2

• The subject expects the US and gets it
• The subject doesn’t expect the US and doesn’t get it
• The subject expects the US and doesn’t get it
• The subject doesn’t expect the US and gets it

Question 3

THE RESCORLA WAGNER MODEL

Answer 3

Theory of surprise - suggests that learning will only take place if what happens is different from what was expected. Excitatory conditioning will take place if the strength of the US is greater than the strength of the expectation, inhibitory conditioning will take place if the strength of the US is less than that of the expectation.

Question 4

Rescorla Wagner - excitatory conditioning

Answer 4

The subject doesn’t expect the US and gets it. This increases its expectation that the US will follow the CS in the future, increasing the associative strength. CS is now more likely to elicit the CR.

Question 5

Rescorla-Wagner : inhibitory conditioning

Answer 5

The subject expects the US and doesn’t get it. This decreases its expectation that the US will follow the CS in the future and the associative strength decreases. The CS is now less likely to elicit the CR.

Question 6

After a reinforced trial, the subjects expectation of the US will increase. The amount of increase will be affected by what two things?

Answer 6

• The difference between the associative strength of the CS and maximum AS the US can support - level of surprise
• The salience of the stimulus - how noticeable was it

Question 7

Delta V = S(A - Vsum)

Answer 7

Rescorla-Wagner model - predicts the change in associative strength that will follow a trial
Delta V = change in assoc strength
S = salience (value between 0-1)
A = maximum assoc strength the US can support
Vsum = sum of the old expectations of each CS

Question 8

OVERSHADOWING

Answer 8

When two CSs are presented together in training, the more salient CS elicits much stronger CRs than the less salient CS, even if the salience difference is small

Question 9

BLOCKING

Answer 9

Pre train the less-salient CS1 with the US before training CS1 and CS2 together, as a result CS2 will not produce the CR and it has been blocked by CS1.

Question 10

THE OVEREXPECTATION EFFECT

Answer 10

Train separately CS1 and CS2 with the same US, both V1 and V2 with approach A. Then, train CS1+CS2 compounded –> US.
At first Vsum will be at 200, and with repeated training on the compound will decrease to A (100).
Then, if CS1 and CS2 were tested separately, they should elicit a much smaller CR than after the initial training.