1. Extinction and Stimulus Control Chapter 8 Dr. Steven I. Dworkin

2. Extinction • Extinction – nonreinforcement of a previously reinforced response resulting in a decrease in the strength of that response, • Both a procedure and a process Dr. Steven I. Dworkin

3. Side Effects of Extinction • Extinction bursts • Increase in Variability • Emotional Behavior – frustration • Aggression • Resurgence (regression) • Depression Dr. Steven I. Dworkin

4. Resistance to Extinction • Resistance to extinction – extent to which responding persists after an extinction period has been initiated. • Schedule of Reinforcement* more intermittent • History of Reinforcement more reinforcers • Magnitude of Reinforcer • Degree of Deprivation • Previous Experience with Extinction • Distinctive Signal for Extinction Dr. Steven I. Dworkin

5. Other Procedures to Eliminate Behavior • Differential Reinforcement of Other Behaviors • Differential Reinforcement of Incompatible behavior • Punishment with DRO or DRI Dr. Steven I. Dworkin

6. Stimulus Control • “All of Psychology is Stimulus Control” • Controlling stimulus- alter the probability of an operant • SD- Discriminative stimulus - sets the occasion for reinforcement of an operant. • Sr sets the occasion for non-reinforcement or extinction of an operant Dr. Steven I. Dworkin

7. Stimulus Generalization • Stimulus generalization – tendency for an operant response to be emitted in the presence of a stimulus that is similar to the SD. • Generalization gradient – graphic description of the strength of responding in the presence of stimuli similar to SD Dr. Steven I. Dworkin

8. Stimulus Discrimination • Stimulus discrimination – tendency for an operant response to be emitted more in the presence of one stimulus than another. • Discrimination training – reinforcement of responding in presence of one stimulus and not another Dr. Steven I. Dworkin

9. Generalization • Generalization - similar behavior in different situations • Generalization gradients - Guttman and Kalish (1956) • Peak shift - Hanson (1959) • Absolute and relative (relational) stimulus control Dr. Steven I. Dworkin

10. Stimulus Control and Multiple Schedules • Multiple schedule - two or more schedules of reinforcement are presented each accompanied by a discriminative stimulus. • Mult VI, EXT • Discrimination index ID =(SD rate)/(SD rate +Srrate) • behavioral contrast- negative association between response rates in two components of a multiple schedule. Change in the rate of reinforcement on one component of a multiple schedule changes the rate of response on another component. • Positive contrast – decrease in the rate of reinforcement in one component increases the rate of response in unchanged component increases • Negative contrast – increase in rate of reinforcement on one component decreases the rate of response the unchanged component decreases. Dr. Steven I. Dworkin

11. Anticipatory Contrast • Rate of response varies inversely with an upcoming change in rate of reinforcement. • More amorous with impending separation. Dr. Steven I. Dworkin

12. Errorless Discrimination and Fading • Errorless Discrimination - Terrace (1963) • S delta introduced early in training • S delta initially presented in a weak form • Problem • Difficult to modify Dr. Steven I. Dworkin

13. Compound Schedules • Mixed • Multiple • Tandem • Chained • Concurrent • Conjunctive • Alternative Dr. Steven I. Dworkin