PSY402 Theories of Learning

1. PSY402Theories of Learning Friday February 7, 2003

2. Discussion of Class Project • Handout on project – see me to get one if you were not in class today. • Plan due next Wednesday – ½ page briefly describing the behavior to be changed and how you will do it. • IMPORTANT – do not use punishment. • Do nothing that would harm yourself or others.

3. Extinction of Operant Responding • Without reward operant responding gradually stops. • Before it stops (is extinguished), it temporarily increases. • After it stops, with a timeout, spontaneous recovery occurs. • This is similar to classical conditioning. • Without reward, spontaneous recovery also goes away.

4. Hull’s Explanation • Environmental cues present during nonrewarded behavior become associated with the inhibitory state. • Example: • A rat runs down alley but gets no reward. • An inhibition response is elicited. • Inhibition is associated with the alley. • The alley evokes inhibition next time.

5. Amsel’s Explanation • Amsel – nonreward elicits frustration, an aversive state. • Environmental cues associated with nonreward become able to elicit frustration. • Escape from frustration is rewarded because the animal feels better (relief). • Operant behavior is not performed in order to avoid (escape) the frustration of nonreward.

6. Nonreward is Aversive • Adelman & Maatsch – animals jump out of box associated with nonreward: • 5 sec if not rewarded • 20 sec if rewarded for jumping out • 60 extinction trials if rewarded, 100+ if not rewarded • Daly – nonreward cues are aversive • Motivate behavior to terminate cue.

7. Nonreward Can Increase Behavior • If frustration cues are associated with appetitive instead of avoidance behavior, responding increases. • Alternation of rewarded trials: • Responding increases after a nonrewarded trial, decreases after a rewarded trial. • Capaldi – animals have a memory for previous reward.

8. Resistance to Extinction • Three factors affect how quickly extinction occurs: • Reward magnitude (in relation to length of training) • Delay of reward experienced during acquisition training. • Consistency of reinforcement during acquisition training.

9. Reward Size • Effect on extinction depends on number of learning trials: • With a few trials, higher reward leads to slower extinction. • With extended training, high reward leads to faster extinction. • D’Amato -- Anticipatory goal states and frustration cause this shift.

10. Effects of Frustration • Frustration builds up when there is a strong anticipatory goal response (expectation of reward). • With small reward, there is little anticipation and little frustration, so only acquisition trials matter. • With more training and large reward, greater anticipation leads to greater frustration which leads to faster extinction.

11. Effects of Delay and Consistency • Only variable delay (not constant delay), when substantial (20-30 sec) makes extinction slower. • Intermittent reinforcement – if the response was not reinforced very time it occurred, extinction is slower. • Partial Reinforcement Effect

12. Partial Reinforcement Effect (PRE) • Extinction is slowest when behavior was intermittently reinforced during learning. • With humans, the lower the slot machine payoff, the longer people play (resistance to extinction). • But, if the percent of reinforced trials is too low, rapid extinction occurs (U-shaped relationship).

13. Explanations for PRE • Two explanations: • Amsel – frustration-based • Capaldi – sequential theory • Both provide good explanations for observed data.

14. Amsel’s Frustration Theory • Frustration leads to rapid extinction during continuous reinforcement. • During intermittent reinforcement, frustration becomes associated with responding. • Frustration then elicits not suppresses responding.

15. Capaldi’s Sequential Theory • If reward follows a nonrewarded trial, memory of the nonrewarded trial is associated with responding. • During continuous reinforcement, animals do not associate lack of reward with responding. • When they encounter the first nonrewarded trial, the state it produces is not associated with responding.

16. Contingency Management • Assessment phase – determine the frequency of behavior and the situations in which it occurs. • Contracting phase – specifies the relationship between responding and reinforcement. • Management phase – implement the contract and evaluate results.