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Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

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Extinction Increases Variability in Behavior Three levers present and Var group had to vary sequence Neuringer, Kornell, & Olufs (2001) All groups increased variability during extinction

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Page 1: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Extinction of Conditioned BehaviorChapter 9

• Effects of Extinction• Extinction and Original Learning• What is learned during Extinction

Page 2: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Effects of Extinction

Extinction involves omitting the US or reinforcer In Pavlovian conditioning, this means repeated presentations of the CS alone In operant conditioning, this means not giving the reinforcer after the response

Two main effects of extinction procedures on behavior the rate of responding decreases response variability increases

Page 3: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Extinction Increases Variability in Behavior

Three levers present and Var group had to vary sequence

Neuringer, Kornell, & Olufs (2001)

All groups increased variability during extinction

Page 4: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Extinction and Original Learning

• Spontaneous Recovery• Renewal• Reinstatement• US-devaluation

Page 5: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Spontaneous Recovery

Rescorla (1996)Rats trained to make 2 different responses for food

Lever-press – foodNose-poke – food

At end of training phase, rats were making about 17 resp/minAfter acquisition, the rats were given 2 20-min extinction sessionswith each responseFor one of the responses, the extinction phase occurred shortlybefore the recovery test (R-No rest)For the other response, the extinction phase occurred 7 daysbefore the recovery test (R-Rest)

At end of extinction phase, rats were making about 2 resp/min

Page 6: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Spontaneous Recovery

Shows importance of passage of time

Page 7: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

RenewalBouton & King (1983)Rats were first trained to bar-press for food

Then, Context AT – Shock

Conditioning resulted in Tsuppressing BP response

During extinction, the rats were divided into 3 groupsGroup A: CS alone in Context AGroup B: CS alone in Context BGroup NE: did not receive extinction

After extinction, all rats received test trials in Context A

Page 8: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Renewal

Page 9: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Reinstatement

Could be due to context conditioning

In initial studies, the excitatory conditioning, extinction and subsequent US exposures were all given in same context

Recent research indicates that context is important but notbecause it permits summation

The role of context appears to be to disambiguate the significanceof a stimulus that has a mixed history of conditioning and excitation

Context has little effect on stimuli that have a history of onlyconditioning

Page 10: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Reinstatement

Bouton (1984)Conditioned suppression with rats

Phase 1CS – weak shockCS – weak shockCS – strong shockCS – strong shock

Phase 2No treatmentNo treatmentExtinctionExtinction

ReinstatementShock-sameShock-differentShock-sameShock-different

TestCSCSCSCS

Reinstatement was introduced when the level of responding was similar in all subjects

However, some rats got to that point by receiving only conditioning,whereas for others the CS was both conditioned and extinguished

Page 11: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Reinstatement

Page 12: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

ReinstatementFor rats that did not receive extinction, it did not matter whetherthe reinstatement shocks were given in the same context or adifferent context

- shows that contextual conditioning did not summate with thesuppression elicited by the CS

For rats that did receive extinction, reinstatement shocks given in the same context produced more suppression than shocks given ina different context

- shows that contextual conditioning facilitates the reinstatementeffect

According to Bouton, reinstatement US presentations given in thetest context serve to restore the excitatory properties of the contextual cues and enable those cues to be more effective inreactivating the memory of excitatory conditioning of the CS

Page 13: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

US-Devaluation

Rescorla (1993)Used devaluation procedure in operant experiment to show thatthe original R-O association was not abolished by extinction

Phase 1R1 – O1

R2 – O2

R3 – O1

R4 – O2

Phase 2R1 extinguishedR2 extinguished

US-devaluation

O1 – LiCl

TestR1 vs R2

andR3 vs R4

The extinguished responses were re-trained with a third reinforcerbefore the devaluation procedure to make sure there would be some responding during the final test

Page 14: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Effect of Devaluation - Operant

Shows that extinction does not eliminate the R-O association

Page 15: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

What is learned in extinction?

The experiments on spontaneous recovery, renewal, reinstatementand US-devaluation all suggest that extinction does not abolish theoriginal learning

So why does extinction produce a decrease in responding?

Extinction may produce an inhibitory S-R association

The non-reinforcement of a response in the presence of a specificstimulus produces an inhibitory S-R association that suppressesthat response whenever S is present

Page 16: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Inhibitory S-R Association

Page 17: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Paradoxical Reward Effects

• Overtraining Extinction Effect• Magnitude of Reinforcement Extinction Effect• Partial Reinforcement Extinction Effect

Page 18: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Partial Reinforcement Extinction Effect

In addition to behavioral effects of extinction, there are also emotional effects (i.e. frustration response)

The most important variable that determines the magnitude of both the behavioral and emotional effects of an extinction procedure is the schedule of reinforcement that was in effect before extinction was introduced

The dominant schedule characteristic that determines extinction effects is whether the response was reinforced every time it occurred (CRF) or only some of the time it occurred (partial or intermittent reinforcement)

Page 19: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

The general finding is that extinction is slower, and involves fewer frustration reactions, if a partial reinforcement schedule, rather than CRF, was in effect before extinction — PREE

The PREE was previously thought to be counterintuitive- if a reward strengthens a response, then CRF should

produce a stronger response and slower extinction

Partial Reinforcement Extinction Effect

Page 20: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Mechanisms of the Partial Reinforcement Extinction Effect

• Discrimination hypothesis• Frustration hypothesis• Sequential memory hypothesis

Page 21: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Discrimination Hypothesis

• introduction of extinction is easier to detect after CRF than partial reinforcement

• with CRF, easier to notice when reinforcementis absent during extinction

• with PRF, not as easy because reinforcement was sometimes absent during training

Page 22: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

2 groups: Phase 1 Phase 2Group 1: CRF CRF ExtinctionGroup 2: partial CRF Extinction

Discrimination Hypothesis

While this idea makes intuitive sense, it was discarded a long time ago.Jenkins (1962)

Extinction procedure should be equally discriminable in the 2 groups

However, group 2 was slower to extinguish

These results suggest that the PREE is not just a discrimination problem but that subjects actually learned something during partial reinforcement that affects the rate of extinction

Page 23: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

Frustration Theory

SF: R SAppetitive With F = frustration

Early in training, after nonreward, the organism is frustrated and expects not to be rewarded on the next trial.

But on some trials following nonreward, the organism is rewarded

Thus the stimuli associated with nonreward (frustration) become associated with reward, and the organism learns to respond in their presence – they become SDs for responding.

SF is present during extinction, thus the organism makes many responses.

Page 24: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

SN: R SAppetitive With N = memory of nonreward

Thus the animal learns to make the response when the memory of nonreward, including sequences of nonreward, is present.

Sequential Theory

Early in training, when the organism is rewarded on a trial after one or more nonreward trials, the organism remembers not being rewarded on those previous trials. That memory then becomes associated with reward on the present trial.

Page 25: Extinction of Conditioned Behavior Chapter 9 Effects of Extinction Extinction and Original Learning What is learned during Extinction

During extinction, the stimulus conditions are always those of non-reward.

Animals that were on PR schedules should make many responses in extinction. They have learned to respond in the presence of stimuli associated with nonreward (either frustration or memory of nonreward).

In contrast, animals that were on CRF, should make few responses during extinction. They have never experienced nonreward, and never learned to respond in its presence. They quickly become frustrated and give up responding.