What do reinforcers and punishers do?

1. What do reinforcers and punishers do? “Learning provides the knowledge, and reinforcers provide the goals to cause the organism to act on that knowledge” (Anderson, 2000, p.119).

2. Rational behavior:

3. Rationality and optimality • Individuals choose rationally within the limits of their knowledge. • Choices that are less than optimal may result from biological or learned preparedness that is inappropriate for a particular situation: Choosing sweet foods over nutritious foods, for example.

4. Rational analysis • Individuals combine the probabilities of particular outcomes with the value of those outcomes to determine the best course of action. For example: • If p(food) is high and the value of food is also high, respond to get food. • If p(food) combined with value of food is lower than p(warmth) combined with value of warmth, respond to get warmth. • If the products are equal, alternate.

5. Comparing rational analysis and Hull • Hull: E = (H x D x K) - I (Recall that H is a product of reinforcement history) • Rational analysis: E = H x (DxK) (that is, p(reward) x value of reward • If two responses are mutually exclusive, both Hull and rational analysis predict the same choice behavior.

6. But what if the same response produces good and bad consequences? • If a bar press produces food 67% of the time and shock 33%, what will the subject do? • It depends on the value of the consequence. • The likelihood of a response is the sum of the products of p(reward) multiplied by value • E = (.67 x 10) + (.33 x -25) = -1.55 • The bar press will not happen until the value of food increases sufficiently.

7. Does reward affect learning? • Rational analysis suggests that reward only influences choice, not learning probabilities. • The surprising conclusion: Learning does not depend on reward.

8. Human research: Within groups • Within-group studies show that differential reward does affect learning (eg. Harley, 1965). Learn these words, for one cookie each: interpolate lexicon musical domicile cyberspace And learn these words, for two cookies each: extrapolate dictionary lyrical dwelling hyperlink

9. Human research: Between groups • Between-group studies show that differential reward doesnot affect learning. GROUP 1: Learn these words, for one cookie each: interpolate lexicon musical domicile cyberspace GROUP 2: Learn these words, for two cookies each: extrapolate dictionary lyrical dwelling hyperlink

10. Can contingencies of reward ever affect learning? • Loftus, 1972: When participants know about differential reward, it affects learning. • More time is spent learning material (more fixations) which promises a higher reward. • Thus, reinforcement can affect attention and effort in learning, if and only if the learner knows about the different consequences while learning. • What do review sheets do to students?

11. An interesting study to do • Begin a study session with no knowledge of differential reinforcement • At some point in the session, inform participants of differential reinforcement • Eg., tell them which items are more likely to be on the exam. • Measure study time (fixation time and/or rehearsal time) for the two sets of items before and after the information is given.

12. Differential reward effects • Differential reward will affect learning only if it enables the learner to allocate attention differentially. • Different levels of reward have no direct effect on learning. You will learn just as much for a dime as for a dollar, if you do not know the difference in reward.

13. Another angle on differential reward • Capuchin monkey fairness protests (deWaal & Brosnan, 2003) • Monkeys trained with different foods as rewards for the work of exchanging differently valued tokens. • Eg, a blue token could be exchanged for a piece of cucumber (low value), a red token for a grape (high value). • They readily learned the exchange rules.

14. But then… • deWaal & Brosnan put the monkeys in pairs, so they could observe each other’s exchanges. • The researchers began giving one monkey a better reward than was justified by the token offered, while rewarding the other monkey by the exchange rules. • The exchange rules monkeys stopped playing the game, or refused the lesser reward. • The effect was greater if one monkey was given handouts. • The monkey given the greater reward never protested.

15. 0 A naive view of contingency consequences

16. 0 A better view of contingency

17. Application question • What is happening when parents ground a child? • Positive reinforcement? • Omission training? • Punishment? • Negative reinforcement?

18. Applying reinforcement • Behavior modification 1: Contingency management • The classroom: Catch them being good • Hall, Lund & Jackson (1968): Robbie, 6/7 classes • But it doesn’t always work • Difficult to be consistent • Different strokes for different folks • Systematic reinforcement: The token economy • Immediate secondary reinforcement • Enhanced subjective reward value through choice • Extra reinforcement for group meeting standards recruits peer pressure

19. Maintaining behavior • Non-reinforcement leads to extinction • But the extinction effect is mitigated by • Partial reinforcement • Reinforcement in multiple settings • Fading

20. But is reinforcement all good? • It uses bribery to play to human greed • It undermines other motivators • Less powerful reinforcers—the negative contrast effect • Intrinsic motivation (Lepper, Greene & Nisbett, 1973) • Internalized control and self-concept/ego ideal

21. What factors influence whether reinforcement will undermine behavior? • High intrinsic motivation is more readily undermined • Perceived coercion undermines behavior • Ryan (1982) • Brehm’s (1966) reactance theory • Reinforcing task completion vs. task competence (Enzle & Ross, 1978)

22. What else can we do to minimize undermining? • Use reinforcement for behaviors with low intrinsic motivation • Use praise rather than material rewards • Reward competence rather than compliance

23. More methods to minimize undermining • Match reinforcement to the optimal motivation level according to the Yerkes-Dodson law • Use the minimum reinforcement necessary • Start with social reinforcers • Use behavioral contracts

24. Aversive control of behavior • Punishment • Observational and correlational research vs. experimental research • Punishment is not necessarily corporal. • Avoidance • How can the non-occurrence of a behavior be reinforced?

25. Principles of punishment • Severity or intensity: Skinner (1938) and Thorndike vs. Boe & Church (1967) and Bucher & Lovaas (1968) • Systematic desensitization (Azrin, Holz & Hake, 1963) • Systematic sensitization • Secondary punishment • Immediacy vs delay (Solomon, Turner & Lessac, 1968) • Delay has no effect on learning to suppress a response. • Delay does reduce perseverance of response suppression. • With humans, delay effects are found in a matter of seconds.

26. More principles of punishment • Consistency/high differential contingency: FR1 vs. FR1000 (Azrin et al., 1963) • Child observation (Larzelere, Schneider, Larson, & Pike (1996) • Criminal activity (Brennan & Mednick, 1994) • Punishment inoculation by non-contingent application (gratuitous punishment: “That was for nothing. Don’t try anything.”) • Reasoning or verbal explanation improves punishment effects, perhaps by assisting discrimination learning.

27. Still more principles of punishment • Since many inappropriate responses persist because they are being reinforced, punishment is more effective if alternate routes to the reinforcer are available. • Poorly done punishment can produce suppression of desirable responses (CER), increased anger and aggression, lying as an avoidance behavior, and imitation of punishing with peers and weaker people.

28. A punishment ideal • Punishment works best when it signals • non-availability of reward for the punished behavior, and • availability of the desired reward if a different behavior is chosen. • Can you think of examples of this approach?

29. Other aversive approaches • Response cost • Randy and the smiley-face chart