Rescorla & Wagner model & Wagner SOP model

Question 1

what gets smaller with each trial

Answer 1

change is associative strength

Question 2

Blocking effect

Answer 2

happens on first trial of stage 2

e.g stage 1 is tone stage 2 is light
tone which reached asymptote by end of stage 1 has blocked learning about the light

Question 3

Mackintosh argued…

Answer 3

that RWM was wrong because he demonstrated that blocking did not occur with only one stage-2 trial. Instead he argued that that an attention-like process was responsible

Question 4

Downshift unblocking

Answer 4

Just like standard blocking except that two shocks are given in stage 1 with an 8 second gap between them
This stopped blocking from happening

Question 5

Dickinson, Hall & Mackintosh’s experiment can’t

Answer 5

easily be explained by RWM.
We could modify λ for stage-1. Let’s call it 2λ, to account for the fact that there are 2 shocks. Fine.

When move to stage-2:
∆V1 = αL * β(λ - ΣV)
∆V1 = αL * β(λ - [ΣVL + ΣVT])
∆V1 = αL * β(λ - [0 + 2λ])
∆V1 = αL * β(λ - 2λ)
∆V1 = αL * β(-λ)

• This means that ∆V1 will be negative. So RWM wrongly predicts that that the light will be an inhibitor, not an excitor.

Question 6

Overshadowing

Answer 6

Stage 1 tone + light , tone overshadowed learning about light
Trial 1 is normal
Trial 2 EV bigger than it would be with just the light, as both the tone and the light contribute to the error term
to RWM overshadowing is just a different way of creating blocking - L and T block one another, if aL = aT learning will stop when EVL = lambdha/2

Question 7

Who first reported overshadowing

Answer 7

Pavlov 1927

Question 8

CS-UCS contingency

Answer 8

Contingency theory proposes that for learning to take place, a stimulus must provide the subject information about the likelihood that certain events will occur

Question 9

Latent Inhibition

Answer 9

Pre exposure to the CS slows the rate of conditioning.
It will get to the same lambdha as it does in non-exposed group, just more slowly

So this is as though the pre-exposure reduces a, it’s just that the RWM has no means of accommodating that.

Question 10

Phenomena that SOP fixes

Answer 10

One-trial overshadowing (e.g James & Wagner, 1980)

Latent inhibition & its “context specificity”

Question 11

Phenomena that SOP will FAIL at

Answer 11

Downshifting unblocking (e.g Dickinson, Hall & Mackintosh, 1976)

Question 12

Phenomena that the Rescorla & Wagner model explains

Answer 12

Conditioning
Configural learning
CS-UCS Contingency
Extinction

Blocking
Overshadowing
Pavlovian inhibition

CCCE BOP

Question 13

Phenomena that SOP explains

Answer 13

Drug tolerance
One-trial overshadowing
Recognition memory
Latent inhibition
Context-specific latent inhibition
Habituation

DORLCH

Question 14

SOP stands for

Answer 14

Standard Operation Procedure

Question 15

Why is SOP different

Answer 15

Ralph Miller described RWM as ‘trial-wise’: We computed change in V after each trial

SOP it operates dynamically in real time

This maps on to the idea that it’s the CS-UCS that’s important

Question 16

Konorski Psychological representations

Answer 16

Composed of divisible elements (aka. units, nodes, gnostic units)

Question 17

Explanation of stimulus generalisation

Answer 17

if two stimuli are “similar” is means that they share representational elements e.g Ax and Bx are similar but A and B are not

Question 18

Hebb suggested…

Answer 18

often summarised as ‘what fires together, wires together’

If they get turned on together, they get connected together

0 < Acs < 1
0 < Aucs < 1

Question 19

Hebb (1949)

Answer 19

Change in V = pi * (Acs * Aucs)

Question 20

Hebb can or cannot explain any of the things that RWM can

Answer 20

Cannot

Question 21

What would be a sensible value for λ when the UCS is NOT presented; e.g., during ‘extinction’ of Pavlovian conditioning?

Answer 21

0

Question 22

What would be a sensible value for λ when the UCS is presented; e.g., in a normal Pavlovian conditioning experiment.

Answer 22

1

Question 23

Imagine a Pavlovian conditioning experiment with the first 12 trials having a mild shock, then the next 12 trials having a medium shock. What values of λ could you use?

Answer 23

1 then 2

Question 24

RWM successfully explains

Answer 24

Blocking
Overshadowing
CS-UCS Contingency effects
Relative validity

Question 25

RWM fails to explain

Answer 25

“Downshift” unblocking
One-trial overshadowing
Latent inhibition

Question 26

How RWM fails to explain downshift unblocking

Answer 26

We could modify λ for stage-1. Let’s call it 2λ, to
account for the fact that there are 2 shocks. Fine.
When move to stage-2:
∆V1 = αL * β(λ - ΣV)
∆V1 = αL * β(λ - [ΣVL + ΣVT])
∆V1 = αL * β(λ - [0 + 2λ])
∆V1 = αL * β(λ - 2λ)
∆V1 = αL * β(-λ)
This means that ∆V1 will be negative. So RWM
wrongly predicts that that the light will be an
inhibitor, not an excitor.

Question 27

Why RWM fails to explain latent inhibition

Answer 27

The pre-exposure to the CS slows the rate of
conditioning. It will get to the same λ as it does in a non-pre-exposed group, just more slowly.
So this is as though the pre-exposure reduces α,
it’s just that the RWM has no means of accommodating that

Question 28

A1 state

Answer 28

Vivid, perception.

Limited capacity

Question 29

A2 state ‘primed’

Answer 29

Weaker. Memory trace or activation by another stimulus
Unlimited capacity

Question 30

I state

Answer 30

Something you’re not sensing or thinking about
Unlimited capacity

Question 31

How SOP explains one-trial overshadowing

Answer 31

When two CSs (T & L) are paired, each one is less active than they would be alone

this means that less will be learned about them—here that an association between T and the UCS is worse when L accompanies T than if T is there on its own.

So the limited capacity feature of A1 activity literally creates overshadowing of T

Question 32

SOP’s learning rules

Answer 32

A1 + A1 = increase in excitatory association
CS –> US

A1 (CS) + A2 (US) = Increase in inhibitory association

Question 33

The representational cycle

Answer 33

An inactive stimulus’ elements (I), become fully active (A1) when is presented, and fade (A2), eventually returning to I

A1 –> A2 –> Inactive

Question 34

Retrieval-generated priming

Answer 34

Inactive —> A2

An associatively-activated representation goes into from inactive, but only to A2 state NOT A1

At λ the presentation of the CS will “prime” most (but usually not all) of the UCS’s
representational elements into their A2 states.—This is what generates the CR in
Pavlovian conditionin

Question 35

Process of Retrieval-generated priming

Answer 35

After the first CS-UCS pairing, the CS’s presentation will prime some of the UCS’s elements into their A2 states, producing inhibition

US is presented, elements that didn’t get primed into A2 will be available to go
into their A1 states, producing excitation.

Early in training, few UCS elements will be primed; but as excitation builds up, priming builds up.

At λ, there is no overall change in the balance of excitation and inhibition. Any overshoot of
excitation will be compensated by extra inhibition on the next trial and vice versa.

Question 36

SOP explains Latent inhibition

Answer 36

the context will retrieval-generate priming in
the CSs representation

This means that the CS’s elements will be in their A2 states, to some extent; ∴ during
Conditioning, they won’t be able to become associated with the UCS.