Chapter 3 - Excitatory and Inhibitory Pavlovian Conditioning

Question 1

What is excitatory pavlovian conditioning?

Answer 1

where a relationship is learned between the CS and the presentation of the US (the CS comes to predict the presence of the US, so we call this CS a CS+)

• the CS activates a “neural and behavioural” representation of the US. in the absence of the actual presentation of the US
• the conditioned response is therefore related to the US

Question 2

What is one important thing to remember about excitatory pavlovian conditioning?

Answer 2

excitatory conditioning does not necessarily involve “excited” behaviour

• if the CR is a reduction in behaviour (ex. freezing), it is still considered excitatory
• can be appetitive or aversive

Question 3

What is a conditioning trial?

Answer 3

the pairing of the CS and the US

Question 4

What is a training session?

Answer 4

multiple conditioning trials

Question 5

What is an intertrial interval (ITI)?

Answer 5

time in between each trial (usually longer than the ISI - otherwise there would be an inhibitory association)

Question 6

What is an interstimulus interval (ISI)?

Answer 6

time between start of CS and start of US

Question 7

What are the conditioning procedures for excitatory pavlovian conditioning?

Answer 7

1. First order conditioning
   a) short delayed conditioning (ISI < 1 min)
   b) long-delayed conditioning (ISI > 5 min)
   c) trace conditioning: CS and US not experienced simultaneously
   d) simultaneous conditioning: CS and US turn ON and OFF simultaneously (no ISI)
   e) backward conditioning: US is experienced first
   - similar results in all 5 first order conditionings (except backwards which can be variable)
   - CS predicts the onset of US in all cases
   - differences between these are that they activate different brain regions

Question 8

Describe the study performed by Bernstein in 1978 on conditioned taste aversion in children receiving chemo?

Answer 8

conditioning phase:
group 1: novel ice cream + chemo (21% chose ice cream)
group 2: new toy + chemo (67% chose ice cream)
group 3: new ice cream, no chemo (73% chose ice cream)
test phase:
give all the patients a choice: play a game or eat ice cream again
- calculate preference for eating ice cream
results: chemo = taste aversion

Question 9

Why are control procedures needed?

Answer 9

1. pseudoconditioning: change in responding to a stimulus whose presentations are intermixed with a US in the absence of an established association
2. sensitization

Question 10

What are the different kinds of control procedures?

Answer 10

1. random control procedures: present the US periodically during both the CS and the ITI (this way the CS does not signal an increase in probability that the US will occur)
2. explicitly unpaired control: present CS and US on separate trials (no conditioning will occur because they were never presented on the same trial)

Question 11

What is a test trial?

Answer 11

presentation of the CS without the US

Question 12

How do we measure conditioned responses?

Answer 12

1. magnitude: size, vigour, length of CR (ex. drops of saliva)
2. probability: % of trials where CR is exhibited (ex. eyeblink conditioning)
3. latency: how soon after CS does a CR occur (ex. port-entry response)

Question 13

What is inhibitory pavlovian conditioning?

Answer 13

a CS comes to predict the absence of a US (represented by CS-)

• can only occur if there is an expectation of a US
• US is more likely to appear when CS- is not presented
• CS will inhibit the behaviour that is elicited by the US

Question 14

Describe examples of aversive conditioning and appetitive conditioning in both excitatory and inhibitory conditioning, respectively?

Answer 14

1. aversive conditioning:
   EC: CS+ associated with shock –> freezing
   IC: CS- associated with no shock –> inhibits fear
2. appetitive conditioning:
   EC: CS+ associated with food –> salivation
   IC: CS- associated with absence of food –> frustration

Question 15

What are the two inhibitory conditioning procedures?

Answer 15

1. standard CI procedure (Pavlov)
   a) type A - promotes excitatory conditioning
   b) type B - CS+ paired simultaneously with CS-
   - random switching between type A and type B introduces two types of learning at the same time
2. negative CS-US correlation
   - CS- predicts the absence of US
   - CS+ comes from environmental context
   - the CS- decreases the probability that the US will occur

Question 16

How can we measure inhibitory responses?

Answer 16

1. bi-directional response systems
   - certain response systems are bi-directional (look for opposite behaviour)
   - some responses may have a low baseline or no true opposite
2. compound-stimulus (summation) test

Question 17

Describe the study performed by Cole, Barnet and Miller (1997) on the summation test?

Answer 17

Phase 1: 
light --> shock (A+)
light + sound --> no shock (Ax-)
light + different sound --> shock (B+)
Phase 2: 
measure how long it takes to accumulate 5 seconds of uninterrupted drinking time
Result:
light = no drinking (fear response)
light + sound x = drinking (no fear)
light + sound y = no drinking (fear response)

Question 18

Describe the retardation of acquisition test performed by Cole, Barnet and Miller (1997)?

Answer 18

• rate of acquisition if excitatory conditioning should be slower for CI (ex. bell = no shock took longer to understand than now bell = shock)

Question 19

What is the role of the CS-US contingency?

Answer 19

(Rescorla, 1968)
positive contingency: can predict (excitatory)
negative contingency: inhibitory
zero contingency: no prediction
- depending on how you pair them in time will determine the learned response

Question 20

Why is it difficult to eliminate a conditioned response?

Answer 20

Because they are involuntary and hard to predict

Question 21

What are two methods of eliminating a conditioned response?

Answer 21

1. extinction

2. counterconditioning

Question 22

What is extinction?

Answer 22

weakening of a learned response that occurs when the CS is repeatedly presented without the US

• works for most associations but can take a long time
• the passage of time can help recover some of the learned behaviour (spontaneous recovery)
• repeated spontaneous recovery results in less intense responses each time
• not dependable/doesn’t always work
• inconsistent initial conditioning makes a CR more resistant to extinction

Question 23

What is spontaneous recovery?

Answer 23

often following a rest period, the CR (previously extinguished) will reappear

• original association is repressed, not unlearned (we learn something new)
• especially likely to reappear if extinction only happened in one context (context dependent)

Question 24

What is counterconditioning?

Answer 24

Replacing an old response with a new, more productive response

• can do this by pairing CS with a positive stimulus (or an incompatible response)
• make sure new response is stronger than the originalCS (so that the opposite effect doesn’t happen)

Question 25

What are some applications of counterconditioning?

Answer 25

1. incompatibility method (Mary Cover Jones)
   - little Peter and white rabbits
2. Threshold method
   - systematic desensitization