• Occurs following the omission of the US (classical conditioning) or the reinforcer (instrumental conditioning)
• Not simple acquisition in reverse (RescorlaWagner)
• Animals learn a new inhibitory relationship
• Also not forgetting (loss of responding can occur but it is not due to extinction it can occurs
without the repeated presentation stimuli)
Extinction in Real Life
• Many examples of resistance to extinction in everyday life (i.e., do not stop a behavior the
first time that it is thwarted). This is an example of resistance.
Eliminating Bedtime Problems with Extinction Training> ▯ >>>>>>>>
• Original behavior persists for a while
• Eventually behavior decreases and Cease completely
• Two effects of extinction most studied:
1. Rate of decrease in responding
2. Changes in response variability
Extinction’s effects: Neuringer et al. (2001)
• Rats in operant conditioning experiment
• One group made to vary their responses; other group was not
• Two groups were then tested for extinction
• Variable respondingà extinctionà even get more variable (the nonfilled dot)
• Nonvariable (yoked group)àextinctionà gets more response just like the extinction burst.
• This was ABAB design so that's why you see two different one.
• Overall, more variability in response was seen in groups that were initially reinforced for variable responding.
• X= session and Y=probability of meeting variance in response. See graph above.
Extinction makes me ‘Emo’
• Frustration : emotional reaction caused by withdrawal of an expected reinforcer
• May energize or lead to aggression
Frustration in Experimental Animals
• Shown in variety of experiment ▯ Tomie et al., 1993: Results
• Procedure: Pigeons: tone (non reinforcement i.e. acted as S) vs. no tone
(reinforcement acted as S+).
• Results: As the session progress, when tone sound, telling them you are not going to
get fed, this increases the behaviorà the animal shows aggression and frustrations as
it was expecting reinforcement but did not get it ▯ bits per session across session
What happens to Original Learning during Extinction?
• Extinction does not reverse/undo original learning
• Several effects that demonstrate this fact:
1. Spontaneous recovery
2. Renewal (restoration of extinction)
3. Reinstatement (& reinforcerresponse memory)
4. Reinforcer devaluation effects
1) Spontaneous Recovery
• After classical conditioning Extinction effects reduced with time
• Loss of extinction evident if subjects tested after a delay (spontaneous recovery)
• Rescorla 1997 studied this phenomenon with rats
Spontaneous Recovery After Classical Conditioning
Procedure: classical conditioning first in all ▯ then extinction was done in these (2 groups
only)▯test after variable number of time had passed after extinction.
• CS for rest (test in these occurred after 8 day extinction training)
• CS for no rest (test in these occurred right after doing extinction training), • Pre CS responding.
Results and graph on the sides:
• CS for no rest▯ iddle of extinction à very low responding (extinction effect was still
• CS for rest (i.e. test again after like couple of days of extinction=rest)à responding
• Pre CS respondingà low= baseline
Main point: original learning has NOT been removed
Spontaneous Recovery after instrumental conditioning:
• After instrumental conditioning
• Extinction effects fade with time
• Loss of extinction evident if subjects tested after a delay
• Rescorla 1996 studied this phenomenon with rats
Results/graph: on the right bottom.▯
• Extinctionà restà see a huge response (same as above study)
MP: Thus extinction has not removed the memory of acquisitions.
2) Renewal of Original Excitatory Conditioning
• Identified by Bouton and colleagues
• Renewal: Recovery of responding when contextual extinctionrelated cues are changed
• Very bad for behavioral therapy
Renewal of Conditioned Suppression: Methods
• Rats trained to press lever for food.
• Tone (CS) paired with shockàTraining in two chambers ( this was for all the three groups)
• After training, 20 extinction trials ( first part of the graph), one group in original (A) context, one in novel (B) context (seconds
part of the graph)
• Then test in A for all group (same context, different context, and not extinction of fear group)
Results and findings:
• Fear extinguishes in different area then testà fear comes back (thus, fear removal with therapist does not carry over).
• Low suppression ratioà no fear ( in the graph=Y axis is this.
Renewal also evident in ( many other learning)
1. Pavlovian appetitive conditioning
2. Conditioned inhibition
3. Instrumental conditioning
4. Relation to drug “state” cues, not just context cues
3) Restoration/reinstatement of Extinction Performance
• Concept of renewal for extinction performance
• Restore extinction effects by reintroducing extinctionrelated cues
• Which seems to Reactivate the memory of extinction
• Seen in a variety of paradigms
Reinstatement of Conditioned Excitation • Recovery of excitatory responding to an extinguished stimulus because of exposures to the US
• For example, Chris can now eat lasagna without a problem, but if he were to get sick (i.e., vomit) again, he may not be able to
continue to do so
• Real problem for behavior therapy (the fear could never be removed)
Reinstatement in humans:
• number of student came into lab and measure the skin conductance as a measure of fear. Show them blue screenàloud noiseà
people get scared à increase in the sweating.
• Extinctionà decrease in response (reduce fear)
• Reinstatement: loud noise beings again in either same or different context.
Finding/MP: during extinction, humans don’t forget about the initial association. The fear response came back in the reinstatement but it
was only increase if this happened in the SAME context (**2,4,5 graphs)
Reinstatement effects in humans:
Results and graphs:
• More fear when the reinstatement is in the same vs. the different context.
• Reinstatement in the same environment give you more bigger response vs. the different response (they don’t care)
Main Point: The shock gives it the context a meaning. Same context ( here we go again we are screwed) and if different context ( oh ok,
Reinstatement Reveals Memory of Specific ReinforcerResponse
4) Sensitivity to Reinforcer Devaluation: Classical Conditioning
• Reinforcer devaluation used to determine if the CSUS association persists through
• Exp. Rats appetitive conditioning with food and sucrose as USs; one paired with light, the