Lecture 2

Question 1

What is temporal contiguity?

Answer 1

• Associations become strengthened when things happen close in time
• If temporal cont is sufficient = learning gradually increases linearly as CS and US are linked
• As long as stimuli are both concurrently present, there are memories that are being associated = temp cont

Question 2

What are the three effects to show temp cont. is not enough to form association?

Answer 2

• Overshadowing
• Blocking
• Contingency
• All result in failure in temp cont to result in learning, and contains conditioned suppression

Question 3

What is condition suppression?

Answer 3

• When there is reduction in response to a previously learnt behaviour due to introduction of new stimulus
• Automated procedure: press lever to get food, and then they press it again and they do not get food = reinforcement once in a while
• Tone comes on and they get a small shock making them freeze
• Tone interrupts tendency to press lever for food, once shock received they press lever
• Can assess if they are scared of the tone
• Results in an expression ratio: ratio of 0.5 means they do not care, as they learn the association, the ratio goes down to 0 (calculated by number of lever presses during tone divided by total lever presses before and during tone)

Question 4

What was a study looking at overshadowing in a conditioned suppression procedure?

Answer 4

• Control group had presentations of light and then shock, exp group gets a light accompanied by a noise and then a shock
• Then tested how often they press lever for food, and how light suppressed lever pulling for food
• If light was all you needed, the ratio should be the same but the noise group shows a higher ratio and thus less scared
• Exp show pairings but not as strong associations
• Noise overshadows the light

Question 5

What is blocking in a conditioned suppression procedure?

Answer 5

• In stage 2, control and blocking are presented with Noise, light and shock
• They should both considerable amounts of freezing
• In first stage, blocking group gets pairing of light and shock
• Then they test indifference in the ratio, so pre-training with lights blocks the noise/shock relationship = no fear to noise even when paired with shock

Question 6

What are contingency effects in a conditioned suppression procedure?

Answer 6

• Three groups: high,med,low
• Tone presented on 10 occasions and on 4 random trials, they are shocked following tone
• Maniupulated that periods between the tones, they would get a random shock not followed by a tone
• High group had no alone shocks, Med = 0.2 alone shocks, Low = 0.4 alone shocks (equivalent to shocks followed by tone)
• High group are most scared, med are a little scared, Low are indifferent to the tone, even though they have pairings to the tone

Question 7

What is the role of surprise in associative learning?

Answer 7

• Perhaps for a change to occur, the shock has to be surprising = increase in associative strength
• In blocking procedure: when noise and light come on, and followed by a shock = surprise, but in exp group = shock is unsurprising due to their pre-learning & don’t learn anything about noise
• In overshadowing = first trial is surprising so association goes up, second trial = expectation of shock = association going up = less than first time but increasing
• In context blocking: presenting shock in absence of tone will allow contextual stimuli that being in the box = shocked = less surprising presentation of shock on conditioning trials with the tone

Question 8

What are the reasons for following the Rescorla and Wagner model?

Answer 8

• Provides intro to one way to capture an idea in a math model that is precise and allows novel predictions to be drawn and tested
• Model related to a class of theories of human cognition that is currently influential
• The model provides a relatively accurate account for a broad range of findings = model incomplete but point of departure of research

Question 9

What is the model?

Answer 9

• The change in associative strength = intensity of CS (fixed for given CS) x Intensity of the US (fixed for given US) (Maximum level of assocaitive strength that a given US can support - the sum of all the assocaitive strengths of the CSs present)
• Shows If one group will show you more or less in different conditions
• Trial by trial analysis

Question 10

What happens during compound conditioning?

Answer 10

• Noise + Light = Shock results in growth of separate associations between the noise and shock and between the light and shock
• Associative strength of the compound is equal to the sum of the associative strength of its components
• THEREFORE if you separately train noise/shock and light/shock, then present the two together then you should see a larger conditioned response that to either of the components alone
• Change in associative strengths of the other stimuli that are also present