Operant Conditioning: Schedules and Theories of Reinforcement

1. Operant Conditioning:Schedules and Theories of Reinforcement Chapter 7

2. Importance of Schedules of Reinforcement • Rule for the presentation of stimuli that precede operants and the consequences that follow them. • Schedules are the fundamental determinants of behavior. • Rate and temporal patterns of responding • Probability of responding.

3. Terminology • Partial reinforcement effect (greater resistance to extinction following partial reinforcement) • Discrimination hypothesis • Generalization decrement hypothesis • Contingency of reinforcement - features defined by the schedule • Steady-state performance • Strained performance

4. Schedules of Reinforcement • CRF - continuous reinforcement FR 1 • Fixed Ratio- FR an FR schedule • Postreinforcement pause • run of responses • Variable Ratio – VR • Fixed Interval – an FI scallop • Long term - break and run • Humans • Variable Interval - VI

5. Reinforcement Schedules • Response based schedules • Fixed ratio FR • Variable ratio VR • Progressive ratio PR • Time Based Schedules • Fixed interval FI • Variable interval

6. Postreinforcement Pause • PRP as a function of IRI • FI - ½ interval value. • FR pause increases as FR is increased, rate of response also increases.

7. Analysis of Reinforcement Schedules • FR postreinforcement pause • Fatigue • Satiation • Remaining response

8. VR and VI response rates • VR yoked VI • Rates are higher on VR schedules even when rate of reinforcement is the same • ?

9. The VR-VI difference • IRT reinforcement • IRTs are conditionable • Synthetic schedules • Response-reinforcer correlation

10. Other Schedules • Response Rate Schedules • Differential reinforcement of low rates • IRT > t • Differential reinforcement of high rates • IRT < t • Differential reinforcement of paced responding

11. Noncontingent Schedules • Fixed time schedule • Variable time schedule • Superstitious behavior • Skinner 1948 • Adjunctive behavior

12. Contingent + Noncontingent Schedules • Decrease in response rate • Long term contracts • Tenure • Noncontingent reinforcement?????

13. Schedule Combinations • Multiple Schedule • Mixed Schedule • Chained Schedule • Tandem Schedule • Concurrent Schedule

14. Factors affecting performance on a schedule • Quality of reinforcer • Rate of reinforcement • Delay of reinforcement • Amount of reinforcement • Level of motivation

15. Rate of Response on Schedules • Dynamic interactions between • Molecular aspects - moment-to-moment relationships • Molar aspects- length of session

16. What Constitutes Reinforcement? • A reinforcer is something that increases the likelihood of the preceding response. • This can be confusing because it leads to a circular explanation. • It can also be confusing because although generally a reinforcer is a pleasant event, it doesn’t have to be. • What constitutes a “pleasant event” can be hard to define or vary from person to person.

17. What Constitutes Reinforcement? • Many reinforcers satisfy biological needs, such as hunger. • Addictive behaviors don’t seem to give much pleasure to the addict (although they may be negatively reinforcing - done to avoid the unpleasant condition of not having access to the drug.) • Some reinforcers don’t satisfy any immediate need, but may represent a future opportunity to have greater access to resources (such as a good grade – you can’t eat it, but getting many of them may raise your chances of having more to eat later in your life.)

18. Theories of Reinforcement • Drive reduction theory – an event is reinforcing to the extent it is associated with a reduction in some type of physiological drive. • However, some types of reinforcers not associated with drive reduction. • Incentive motivation – reinforcement derived from some aspect of the reinforcer.

19. What Constitutes Reinforcement? • The Premack Principle • The Premack Principle states that the opportunity to engage in frequent behavior will be a reinforcer for any less-frequent behavior. • A person who prefers going to the movies to going to museums can be reinforced for extra trips to the museum with free movie passes.

20. What Constitutes Reinforcement? • The Disequilibrium Principle • The disequilibrium principle states that each person has a preferred pattern of dividing time between various activities and if the person is removed from that pattern a return to it will be reinforcing. • A person who must work overtime for the next three weekends makes an extra effort to finish up the assigned work to return to his preferred activity of playing golf.

21. Response Deprivation Hypothesis • A behavior can serve as a reinforcer when (1) access to the behavior is restricted and (2) and its frequency thereby falls below its preferred level of occurrence.

22. Behavioral Bliss Point Approach • An organism that has free access to alternative activities will distribute its behavior in such a way as to maximize overall reinforcement. • Contingencies can move us away from the bliss point. • Organism will try to accommodate by maximization of bliss point.