Becoming Extinct

Extinction of Conditioned behavior Extinction is a typical part of the learning process – Pavlovian or Instrumental contingency can change Go to you favorite pizza place and they are closed Put money in a vending machine and nothing comes out Key (card) does not open the lock – whenever reinforces or the unconditioned stimulus no longer occur Extinction is evident by decreased responding – conditioned response in Pavlovian procedure decreases – operant response in instrumental procedure decreases For extinction to occur need to have acquisition – CS tone --> food then CS tone --> No food – lever press --> food then lever press --> No food Extinction is not forgetting, – it is learning a new contingency, i.e. the US or reinforcer is no longer available Clinical application using exposure therapy for phobias

Effects of Extinction Procedures Extinction has Behavioral effects: Decrease in responding Increases variability of behavior – Neuringer, Kornell, & Olufs (2001) – Two levers (left bar, right bar) and a key light – Need to make a sequence of three response to get a food reinforcer [left, right, left] or [key, left, left] or [right, right, right] – Variable response group had to vary sequence of responses. – Control group » did not have to vary responses could use [right, right, right] » was yoked to variable response group so they got the same pattern of reinforcers. – Both groups decreased responding during extinction – Both groups increased variability during extinction. Figure 9.1 Basic structure of behaviour is not changed, rats continued to try familiar sequences, just less often

FIGURE 9.1 Effects of extinction on response variability (left panel) and response rates (right panel) for rats that were required to perform variable response sequences for reinforcement (Var) or received reinforcement regardless of their response sequence (Yoke). The open symbols represent the last four sessions of the reinforcement phase. The filled symbols represent the first four sessions of the extinction phase. (Response variability was measured in terms of the probability of meeting the variability criterion. Response rate was measured in terms of the number of three-response sequences that were completed per minute.) Based on Neuringer et al. [2001]. Journal of Experimental Psychology: Animal Behavior Processes, 27. Figure 4, p. 84.) The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Effects of Extinction Procedures Extinction has – Emotional effects energizes behavior, arousal is a general emotional effect Frustration when reinforcer does not occur extinction-induced aggression, – Pigeon alternated between CRF and extinction – During extinction it would attack another pigeon – Has been demonstrated in pigeons, rats and humans » Kicking the vending machine A big problem when using extinction in behavior therapy – Tend to get frustration and acting out early in extinction

Extinction Check List To reduce student misbehavior in a classroom Select extinction and replacement behaviors Ignore misbehavior/reinforce replacement behaviors Monitor student performance Potential Problems and Solutions – only works for attention seeking behavior – extinction burst: during extinction inappropriate behavior will suddenly escalate – spontaneous recovery of misbehavior – reward good behavior – misbehavior is rewarded by other students’ attention, comments, or laughter

Forms of Recovery From Extinction Extinction does not erase original learning – Extinquished responses will reappear – This is a problem when using exposure therapy Evidence from spontaneous recovery, renewal, reinstatement and resurgence Spontaneous Recovery With just the passage of time behavioral response will return after extinction The recovery of behavioral responses is similar for Pavlovian or instrumental conditioning Does not return to the maximum responding achieved during conditioning. Indicates that extinction is not the reversal of conditioning.

Forms of Recovery From Extinction Example of spontaneous recovery using Pavlovian conditioning – Rescorla (2004) using a sign tracking procedure – light (CS1) -- food (US) ---- head poke (UR) – noise (CS2) -- food (US) ---- head poke (UR) – Extinguish head poke behavior by not presenting food – Test CS either: (CS2) immediately after extinction (CS1) 8 days after extinction – Figure 9.2 CS2 shows no spontaneous recovery CS1 has spontaneous recovery

FIGURE 9.2 Rate of rats poking their head into the food cup (goal tracking) for two different CSs. The left panel shows the original acquisition of responding to the two stimuli (averaged together) when each was paired with food. The middle panel shows loss of responding during the extinction phase. The final test trials were conducted right after extinction for S2 and eight days after extinction for S1. Note that the eight-day rest period resulted in a substantial recovery of the conditioned behavior. (From Rescorla, Learn. Mem : Copyright © 2004, by Cold Spring Harbor Laboratory press. Page 05.) The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Forms of Recovery From Extinction Renewal of Original Excitatory Conditioning Restoring conditioned responding to an extinguished CS by shifting away from the contextual cues that were present during extinction – either a return to the acquisition context or a neutral context Bouton (2011) – Group No Exposure Acquisition: lever press(R) - food (O) in context A Extinction: All rats got 4 sessions of extinction “no food” in context B Testing: two test sessions – One in Context A (the acquisition Context) – The other in Context B (the extinction Context) – Group Exposure Same acquisition as above Same extinction to context B Plus exposure to context A without lever or food Same testing as above

Forms of Recovery From Extinction Renewal of Original Excitatory Conditioning Bouton (2011) using conditioned suppression procedure – Renewal of responding when returned to Context A Figure 9.3 – Extinction in context-B: learn that food is not available in context B This learning does not transfer to context A Called the ABA renewal effect – Extinction is not unlearning of the fear response, it is additional learning – No differences in responding between No Exposure and Exposure groups No exposure group learns there is no food in context B Exposure group could not press the lever and no food to eat in context A – Also learns that context B has no food – However, additional exposure to context A (without lever or food) has no effect on responding in context A – Acquisition in Context A does not produce (S-O) context-food association – Recall from previous examples, » a discrete light (S) lever press (R) food (O) will form an association between light and food

FIGURE 9.3 Renewal of extinguished lever pressing in rats reinforced by food. Acquisition was conducted in context A. Extinction was conducted in context B. The rats were then tested in both context A and context B. Group Exp also received extinction of context A during the extinction phase. Group NoExp did not received this context extinction procedure (based on Bouton et al., 2011). The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Forms of Recovery From Extinction Renewal of Original Excitatory Conditioning Renewal effects indicate that memories of extinction are specific to context cues present during the extinction phase – Acquisition is less context specific than extinction Will generalize across context ABC procedure: acquisition in A, extinction in B, testing in C – Will produce responding in context C but not B – Extinction is context specific So memory of extinction is separate from memory of acquisition – Separate memories for acquisition and extinction context makes it possible to keep track of same stimulus red light under different situations – “Contextual cues serve to disambiguate the significance of the CS” – When context is “place” information Foraging behavior: searching for food across many place Context “place” specific information for where there is no food

Forms of Recovery From Extinction Renewal of Original Excitatory Conditioning Because acquisition is not context specific what you originally learn in one context generalizes to other contexts easily – This is usually a good thing in that fear of a snake should be fear of a snake no matter where you are – However, over generalizing can create problems when fear of snake prevents you from going to the Zoo or even going outside This is important for use of extinction in therapy – get extinction training in therapists office – such as exposure therapy for fear of insects – but does not carry over to home environment Can reduce or prevent renewal effect by doing extinction training in a number of contexts