Schedules of Reinforcement Chapter 13

2. Schedules of ReinforcementChapter 13

3. What’s a Schedule? • A schedule of reinforcement is a rule specifying… • the arrangement and response requirements for reinforcement • e.g., whether a reinforcer follows every behavior, every other behavior, etc. • 2 Simple Schedules • Continuous Reinforcement (CRF; FR1) • The reinforcer follows every behavior • CRF results in rapid acquisition (good for teaching) • CRF produces little resistance to extinction • Extinction (EXT) • Discontinuation of a response-reinforcer contingency

4. Intermittent Reinforcement • Some rather than all responses are reinforced • Two main categories • Ratio schedules: the reinforcer is delivered after every X behaviors • Interval schedules: the FIRST behavior after X amount of time is reinforced • Produces better resistance to extinction than CRF • Good for maintaining behavior

5. Ratio Schedules • 2 Types: Fixed Ratio and Variable Ratio • Fixed Ratio: the reinforcer is delivered after a fixed number of behaviors • Designation: FR 5 (every 5th target response is reinforced) • Produces high-rate responding – why? • Produces a post-reinforcement pause (PRP) • PRPs are proportional to the size of the ratio • e.g., piecework

6. Fixed-Ratio Schedule of Reinforcement PRP SR+ delivered

7. Variable Ratio • The reinforcer is delivered after an average number of behaviors • Designation: VR 5 • 5, 4, 7, 6, 4, 3, 6, 7, 3 • Produces consistent, high rates with no PRPs • e.g., starting a lawn mower • Clinical applications…

8. Tic-Tac-Toe VR Procedure • Teacher picks maximum number of responses for an individual or group (e.g., 30) • The smaller the #, the more likely it is that the learner(s) will meet the contingency • Learners fill in each square of tic-tac-toe grid with a # no greater than the max • Teacher fills box with numbers on slips of paper • Each number several times • Contingent on target behavior, student picks slip of paper • If on tic-tac-toe, cross out number • Deliver SR+ when 3 in a row 5

9. Classroom Lottery VR Procedure • Students write their names on index cards after successfully completing assigned tasks • Cards go in a box • After a preset period of time (e.g., 1 week),… • Teacher picks a card – that student is the winner • The more cards earned, the more likely a student will be the winner Reggie Lottery Box!

10. Considerations with Ratio Schedules • Both FR and VR schedules have 2 major advantages • Produce high rates of responding • Easy to use • Potential Disadvantage • Ratio strain can result from abrupt increases in ratio requirements

11. Interval Schedules • 2 Types: Fixed Interval and Variable Interval • Fixed Interval: the reinforcer is delivered for the first target response after a fixed period of time has elapsed • Designation: FI 60s • e.g., turning on the TV to watch your favorite show • Characteristics • Produces PRPs, resulting in scallop or break-and-run patterns • Slow to moderate rate of responding

12. PRP SR delivered

13. Variable Interval Schedule • the reinforcer is delivered for the first behavior after an average period of time has elapsed • Designation: VI 60s • produces steady, moderate responding (no PRPs) • e.g., checking e-mail • Limited Hold: a feature that can be added to any interval schedule • The behavior must occur after the interval has elapsed, but within a specific period of time • Designation: FI 5 min LH 30 s

15. Considerations with Interval Schedules • Use if you want to produce low to moderate response rates • Advantage • FI schedules are relatively easy to use with a resetting timer • Potential Disadvantage • Off-task or other unwanted behavior may occur during the PRP

16. # responses FI scallop Post-reinforcement pause time

17. Thinning the Schedule of Reinforcement • Schedule thinning:Gradually increasing the response ratio or the extent of the time interval • Benefits • The student’s behavior becomes more durable (more resistant to extinction) • More practical for caregivers to implement • If you move too quickly, you can produce ratio strain • Aggression • Extinction of responding • Not many guidelines are available to tell us how to do this

18. LeBlanc, Hagopian, Maglieri, & Poling (2002) • Determine a reasonable terminal goal that’s appropriate to the age and functioning level of the learner • Establish a series of steps between the initial value and the terminal value • 8-12 steps are recommended • Increase 33% to 50% at each step • Stay at one step at least 2 times • If student is unsuccessful, go back a step • Periodically probe a few steps ahead

19. LeBlanc et al.: Thinning from FR1

20. Differential Reinforcement of Rates of Responding • DRH: Reinforcement of responses higher than a predetermined criterion (to produce a higher rate of responding) • DRL: Reinforcement of responses lower than a predetermined criterion (to produce a lower rate of responding) • 3 Types • Spaced-responding: reinforcement is only available for responses separated by a given duration of time (IRT) • Not used much b/c it’s difficult to calculate IRT • Full session: reinforcement is delivered at the end of the session if the total number of responses during the session was less than or more than a criterion • Interval: Total session is divided into equal intervals and reinforcement is delivered at the end of each interval in which the number of responses was less than or more than a criterion

21. Compound Schedules of Reinforcement • Combine different types of schedules • Concurrent Schedules • Discriminative Schedules • Multiple Schedules • Chained Schedules • Nondiscriminative Schedules • Mixed Schedules • Tandem Schedules

22. Concurrent Schedules • 2 or more contingencies of reinforcement operate independently and at the same time for 2 or more behaviors • Used for • Reinforcer Assessments • Intervention Assessments • Hanley et al. (2005) allowed individuals to choose which intervention they preferred • FCT + Punishment was preferred to FCT + Extinction • Interventions • Hoch et al. (2002) – boys with autism could play alone or with sibling • Sibling was chosen when SR magnitude and quality were increased • Use this when you can’t or shouldn’t treat inappropriate behavior directly

23. Multiple Schedule • A type of discriminative schedule • Two or more schedules are presented one after another • Each is correlated with a discriminative stimulus • Tiger and Hanley (2004) • Different colored leis worn by the teacher were SDs correlated with schedules of reinforcement for attention

25. FR1 Component (SD)

26. EXT Component (S∆)

27. 15 s – 270 s 5s–1s 1 s – 60 s Minimum response criterion

28. Chained Schedule • A type of discriminative schedule • Differs from multiple schedule: • Schedules in the chain occur in the same order • Behavior may be the same or different for each component of the chain • Conditioned reinforcement for the first element of the chain is presentation of the second element • The last response is reinforced with most powerful reinforcer

29. Nondiscriminative Schedules • Mixed (like multiple schedule without the SDs) • Tiger and Hanley (2004) – conducted the same sessions without the teacher wearing leis • Tandem (like chained with out the SDs)

30. Use Caution… • When extrapolating information about schedules from basic research to applied settings • Most applications of schedules only approximate lab schedules • Many uncontrolled variables in applied settings will influence a person’s sensitivity and insensitivity to a schedule of reinforcement