Extinction of Conditioned Behavior

• Effects of Extinction• Extinction and Original Learning• Paradoxical Effects in Extinction

Effects of Extinction

Extinction involves omitting the US or reinforcerCS alone, no US R alone, no outcome

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

Extinction and Original Learning

• Spontaneous Recovery• Rapid Reacquisition• Renewal• Reinstatement

Spontaneous Recovery

CS1 – USCS2 – US

AcquisitionExtinction 1

Extinction 2

Wait

Test

CS2 – nothCS1 ?CS2 ?

CS1 – noth 2 weeks

Longer wait after extinction, more spontaneous recovery

Spontaneous Recovery

Shows importance of passage of time

Rapid Reacquisition

• Re-acquisition after extinction is normally quite rapid. – So, the original learning was preserved

somewhere although there was no performance

Renewal

Context A

Pairings Extinction CS Test

Context A2. Context B

A return to the context of acquisition after extinction of the CRin a different context causes CR recovery (ABA renewal)

3. No Extinction

1. Context A

Renewal

Mechanisms• Subjects turn to the context to disambiguate the meaning

of the CS– CS->US in acquisition (A) – CS->no US in extinction (B)

• Inhibitory association is specific to Context B?– A change in context after extinction of the CR causes CR recovery

(ABA renewal)– ABC causes renewal, which suggests a return to Context A is not

necessary– AAB renewal– ABC renewal is normally weaker than ABA renewal, so a return

to the context of acquisition may play some role

Reinstatement

Context A1

Pairings Extinction

A return of contextual excitation reinstates the extinguished CR

Context A1 = US present sessionsContext A2 = US absent sessions

Context A2 Context A1

US alone then CS

Lindblom-Jenkins Effect

Context A

PairingsUnpaired

CS and US CS Alone

Removal of unsignaled USs present only in extinctioncauses recovery of the CR

Context B Context A

Reinstatement

Erasure and Reconsolidation• Expose subject to already “CS” for one trial• While subject is thinking about the “CS”

and its associated “US”, give them a memory erasure drug, MK501.

Memory Erasure

• Stronger Learning ≠ Slower Extinction• Partial Reinforcement Extinction Effect or

PREE

Extinction Paradox

Acquisition with Differing Percentage Schedules

Spee

d

Day

100%

80/50/30%

Extinction with DifferingPercentage Schedules

Spee

d

Day

80% 50% 30%

100%

Explanations

• Mowrer-Bitterman Discrimination Hypothesis• Amsel’s Frustration Theory (Emotional)• Capaldi’s Sequential Theory (Cognitive)

Theios ExperimentPHASE 1 PHASE 2 EXT

G1 100% 0%

G2 100% 100% 0%

G3 50% 100% 0%

G4 50% - 0%

Extinction Experiment

Extinction Trials

Spee

d

G1, G2 100%

PHASE 1 PHASE 2 EXT

G1 100% 0%

G2 100% 100% 0%

G3 50% 100% 0%

G4 50% - 0%

G3, G4 50%

Amsel’s Frustration Theory

Amsel’s Frustration Theory

100% Reinforcement Group

Amsel’s Frustration Theory

50% Reinforcement Group

Amsel (extinction data)

Extinction Trials

Spee

d

100% 50%

AmselEXT

BETWEEN SUBJECT

GROUP 1 T F 100%

T-

GROUP 2 N F 50%

N-

WITHIN SUBJECT

TRIALS 1,3,6….

TF 100%

T-

TRIALS2,4,5….

NF 50%

N-

PREE

ReversedPREE