Classical Conditioning II

Question 1

Rescorla-Wagner Model

Answer 1

Learning will occur only when the subject is surprised
Big surprise= lots of learning
Small surprise= less learning

Question 2

Blocking Experiment

Answer 2

Developed by Leon Kamin

Blocking- 
phase 1- Light paired with US
phase 2- Light and tone paired with US
Test- Tone presented
Result- No CR (US in phase 2 is not surprising because US is predicted by light)

Control-
phase 2 (no phase 1)- light and tone pairs with CS
Test- tone
Result- CR

Conditioning is not an automatic result of CS-US pairings

For conditioning to occur, the CS must be informative and the US surprising

* Once you have the perfect predictor you don't need anything else
* CS blocks learning to other CS (only care about light, don't care about tone)

Question 3

Associative Strength (V)

Answer 3

Associative strength between CS and US

Learning strengthens associative strength

Each trial changes associative strength, but amount of change gets smaller and smear because US becomes less and less surprising

Conditioned inhibitors (CS-) have negative associative strength

Question 4

Quantification of How Surprising US IS

Answer 4

Delta V= V max - V n

V n - strength of association at beginning of trial n

Delta V - change is the strength of association produced by trial n

Question 5

Learning Curves

Answer 5

Differ in terms of V max, rate of acquisition

Question 6

V max

Answer 6

Determined by magnitude of the US

Stronger US= bigger V max

Question 7

Alpha

Answer 7

Salience of CS

Value between 0 and 1

Question 8

Beta

Answer 8

Salience of US

Value between 0 and 1

Question 9

Rescorla Wagner Model

Answer 9

Learning will occur only when the subject is surprised
Big surprise= lots of learning
Small surprise= less learning
Delta V n= alpha * beta * (Vmax - - V n)
or
Delta Vn= alpha beta(Vmax- sum of V n)

Question 10

Extinction of a Conditioned Response

Answer 10

Weakening of conditioned response when CS is presented by itself (no US)

Vmax= 0

Question 11

Explanation of Blocking

Answer 11

Beginning of trail- when 2 CS are used, associative strength of both stimuli is the sum of the individual stimuli

Blocking group- 
V max (light) is 1.0 due to extensive conditioning, but the tone is new (introduced in phase 2) so V(tone)=0

V (light+tone)=1.0+0= 1

Delta V(tone)= 0.3 (1.0-1.0)=0

Question 12

Over Expectation

Answer 12

Extensive conditioning -Pair tone with shock, then pair light with shock, when tone and light presented, expect larger shock because both stimuli are presented

When the same intensity of shock is given, subject becomes less fearful of both stimuli

Question 13

Rescorla: Over Expectation Experiment

Answer 13

Phase 1:
Experimental Group- Tone + Light -> shock
Control group- nothing

Phase 2:
Both groups-
Tone-> shock
Light -> shock

Results showed that control group (no extensive conditioning) was more fearful

Question 14

Contextual Stimuli

Answer 14

When US not contingent to CS conditioning will be strong to contextual stimuli but not to CS

CS is not always presented, but context (background) is always there, so a response to CS decreases, and a response to context increases

Question 15

Problems with Rescorla-Wagner Model

Answer 15

Exclusive focus on “surprisingness of US”

Assumes alpha does not change, but it is not always constant

Conclusion that extinction removes original learning (ignores spontaneous recovery, renewal, reinstatement, rapid reacquisition)

Question 16

Spontaneous Recovery

Answer 16

Reappearance of a CR to a CS after a period of time following the last extinction trial

Extinction adds new learning, just a different kind (competes with original learning)

Question 17

Renewal

Answer 17

Reappearance of CR to CS due to return to training environment, instead of environment used during extinction

Question 18

Reinstatement

Answer 18

Reappearance of CR to CS due to a brief presentation of US

i.e Tone/Shock pairing, extinction, then shocked night before…. next day, CR to CS (tone) appears again

Question 19

Rapid Reacquisition

Answer 19

Rapid return of a CR to a preciously extinguished CS (shorter amount of time to recondition)

Question 20

Prediction Error

Answer 20

Delta V= prediction error

Large delta V, US not predicted, very surprising

Small delta V, US predicted, much less surprising

Question 21

Dopamine

Answer 21

Neuromodulator involved in learning, motivation, and variety of psychobiological functions

Question 22

Wolfram Schultz

Answer 22

Juice comes out of spout, measures response from monkeys

Presents visual stimuli, monkeys associate image with juice

Discovered that after conditioning, dopamine spike after CS, not after juice

Therefore, dopamine is involved in prediction, not pleasure. Overtime something meaningful that is not predicted happens, dopaminergic neurons respond

Question 23

Autoshaping/ Sign Tracking

Answer 23

Doesn’t require action from subject to get reward

Pair light with grain, pigeon starts pecking at light (even though it doesn’t need to)

Question 24

Goal Tracking Behaviour

Answer 24

Tracks goal (food)
Primarily uses US
(tracks food, not light)
Dopamine response to CS and US, response to both stay the same