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Psy 356 04/08/2010 I. Extinction Review - Extinction produces: o Multiple attempts o Increased response variability o Frustration - Extinction does not reverse acquisition! So how could spontaneous recovery contribute to getting back together Renewal rekindle the old flame o CONTEXT IS IMPORTANT IN RENEWAL Reinstatement leads to “another try” o Seeing an individual can renew U.S Extinction II. Reinforcer Devaluation in Extinction Rescorla (1993) Results - Devaluation in non-extinguished rats decreased FR3 Devaluation in extinguished rats decrease R1 The R-O association persists despite extinction This is also true of the CS-US relationship and the S-O relationship What is learned during extinction? Pavlovian Conditioning: S-S appears more important than this S-R Instrumental Conditioning R-O and S-O associations are more important than S-R - S-R associations are most important in extinction -S-R association can account for renewal and reinstatement - Non-reinforcement produces an inhibitory S-R association Therefore, non- reinforcement in the presence of specific stimuli (S) produces an inhibition of response ® Ex: Renewal- the extinction context is often the specific stimulus (S) Courtney Love example III. What is learned in Extinction A. The S-R association - The inhibitory S-R relationship is dependent upon a history of reinforcement: - Every response that is not reinforced leads to frustration Psy 356 04/08/2010 - This aversive emotional reaction produces the inhibitory S-R relationship (“Why even try?”) B. Inhibitory conditioning ( Does extinction make the CS and inhibitor?) 1. Train A+/B+ 2. Train A- Summation Test Ext A- Test Test: AB Retardation Test Ext A- Train A+ Does A inhibit responding to B? YES!! <= Does A inhibit manipulation? YES! Question1 Extensive reinforcement training should slow the rate of extinction? False, because of overtraining Question 2 Responding declines more rapidly in extinction following reinforcement with a larger reinforcer True, because the organism becomes frustrate Question 3 Continuous reinforcement produces more resistance to extinction than partial reinforcement False, because IV. Paradoxical Effects of Extinction A. Overtraining: If decreased responding is due to frustration of unexpected lack of reinforcement, more rapid extinction should occur when expectancy is higher Paradox: A true statement leading to a contradiction of intuition - Does more extensive training produce resistance to extinction? NO! Ex: Puppy training B. Magnitude Reinforcement extinction effect: More rapid extinction should occur when reinforce expectancy is larger - Does responding decrease more rapidly in extinction following training with a larger reinforcer? YES! Ex: Allowance and chores $10 decrease rate of extinction $100 increase rate in extinction - The larger the reward the higher the rate of extinction ( High and low contrast) Psy 356 04/08/2010 C. Partial Reinforcement Extinction Effects (PREE): Extinction is slower if partial rather than continuous reinforcement was previously in effect Ex: Continuous reinforcement ATM machine Response Dip card in Partial reinforcement Playing roulette Sometimes you win and sometimes you lose Reinforcer Get money V. Mechanisms of PREE - PREE in rat pups: Chen and Ansel, (1996) - Subjects rats - 10 D old -12 D olds Training Alley running (speed) Reinforcer: Milk - Continuous reinforcement (CRF) - Partial reinforcement (PR) Extinction Removal of reinforcer Findings: - Rats start running faster for CRF - P13 rat extinction CRF > PR P11 rat extinction CRF=PR - PREE is acquired by P13 and is likely based on brain maturation A. Discrimination Hypothesis: Introduction of extinction is easier to detect after continuous reinforcement vs. partial reinforcement Jenkins (1962) and Thelps (1962): Test of discrimination theory Group 1 Group 2 Training 1: PR CRF Training 2: CRF CRF Extinction Immediately after training 2 Findings Group 1: Demonstrated more resistance to extinction B. Frustration Hypothesis: Persistence in extinction results from learning to respond when you expect to be non-reinforced or frustrated Psy 356 04/08/2010 - Dependent upon intermittent reinforcement the presentation of random reinforced and nonreinforced trials Early training => Reinforcement increases responding Reinforcement decreases responding Late Training Reinforcement increases responding Reinforcement increases responding - Non reinforcement leads to expectation of no reward, so when they are unexpectedly reinforced with training responding increases C. - Sequential Hypothesis: Subjects remember rewarded trials followed by nonrewarded trials and the memory of the nonrewarded trials serve as cue for the next reward The memory of reward created a “It’s got to happen sooner or later” idea VI. Behavioral Momentum Hypothesis” Not a paradoxical reward effect suggesting persistence in extinction may represent resistance to change in the face of extinction - Suggests that behavior with momentum is difficult to stop P= m*v P= momentum M= mass V= velocity While this theory is useful for comparing rates of reinforcement, it has difficult for accounting for PREE