PSY 402

1. PSY 402 Theories of Learning Chapter 9 – Motivation

2. Hull’s Response • Spence modified Hull’s drive theory to include findings of incentive motivation. • K was added to account for incentive. • Behavior strength = D x H x K • Drive is innate and internal, incentive is learned and external. • Drive pushes behavior, incentive pulls it.

3. Fractional Anticipatory Goal Reactions • The idea of a motive seemed mentalistic – how can a behavioristic theory explain expectations and goals? • rG-sG mechanism -- Intermediate states between the initial behavior and the goal are chained together by associations (classical conditioning). • RG = goal reaction or response (capital R) • rG = association of goal box with goal reaction (small r) • sG = similarity between start and goal box evoked rG & salivation, which becomes a stimulus motivating response

4. Frustration • Amsel extended the idea of rG-sG mechanisms to negative contrast (explained by the mentalistic concept of frustration). • Expectation of a big reward (RG) but receipt of a small reward results in frustration (RF). • The size of RF is the discrepancy between previous rewards and the current reward size. • rF also becomes generalized to the goal box and start box to demotivate (reduce responding).

5. Paradoxical Reward Effects • In some situations, reward seems to weaken, not strengthen responding. • Negative contrast is one example – a perfectly good reward fails to motivate responding. • Magnitude of reinforcement effect -- reinforcement with a large reward leads to faster extinction than reinforcement with a small one. • Overlearning extinction effect – many rewarded trials extinguish faster than a few rewarded trials.

6. Effects on Intrinsic Motivation • Rewarding a behavior that was previously performed for intrinsic reasons (internally motivated) leads to reduced behavior. • Preschoolers expecting reward drew less. • “Punished by reward” phenomenon – some suggest that rewarding creative activity may hurt it. • Reward effects are relative and complex (affected by many factors).

7. Skilled Use of Reward • Performance decreases in situations where: • Rewards were tangible (money) • Announced ahead of time • Given in a way that was not dependent on performance. • Reward is perceived as a way to manipulate or control someone. • Performance increases when verbal praise is given, when reward is unexpected, relevant.

8. Persistence of Behavior • Partial reinforcement extinction effect (PREE) – behavior is more resistant to extinction when it is reinforcement intermittently. • Continuous reinforcement – acquired faster and extinguished faster. • Partial reinforcement (50%, VR-2) – acquired slower and extinguished slower. • Persistence generalizes to other tasks – learned industriousness.

9. Theories about PREE • Amsel’s frustration theory -- animals learn to respond in the presence of frustration. • Frustration attaches to the stimulus (sF) after an unrewarded trial, then responding to it is rewarded. • Capaldi’s sequential theory – the rat has a memory of responding after a non-reinforced trial. • It responds because the stimulus is familiar.

10. New Understanding of Extinction • Extinction involves new learning that is dependent on context. • Research on PREE suggests also that: • Extinction occurs when generalization from acquisition trials stops (generalization decrement) • Frustration occurs and reduces motivation when an expected reward does not occur, but is not needed to explain PREE.

11. Problems with rG-sG • If classically conditioned associations motivate behavior, they should correlate with responding, but they don’t. • Concurrent measurement studies showed little correlation between salivation and responding rewarded by food. • In studies of shock avoidance, fear (rE) showed little correlation with vigor of avoidance. • Central states not peripheral should be measured.

12. Transfer of Control • Increasing or decreasing the intensity of an internal state (expectancy) should affect behavior. • Pavlovian-Instrumental Transfer. • An instrumental behavior and a CS are both learned separately. • When paired with each other, behavior should increase. • Dogs in shuttle box showed this effect.

13. Effects of Pavlovian CS’s • Some of the effects of Pavlovian inhibitors on instrumental responding occur because of evoked fear. • Rat freezing due to fear interferes with avoidance. • Excitatory Pavlovian CS’s can activate an entire system, not just a specific response. • In other contexts, the effect of the CS is specific to the type of reward (food vs water). • The explanation for this is unclear.

14. Practical Applications • Classical conditioning (CS’s) are always present and affect instrumental behavior. • Obsessive checking behavior is worse when anxiety is heightened by a CS, better when less fear is evoked. • CS’s associated with a drug increase the motivation for drug-taking behavior. • CS’s evoke a system of responses one of which may be instrumental behavior.

15. Opponent-Process Theory • Emotional after-reaction – an emotional stimulus creates an initial response that is followed by adaptation, then opposite response. • With repeated exposure to the stimulus, the pattern changes. • The primary affective response (a-process) habituates. • The after-reaction (b-process) strengthens

16. Imprinting • Baby ducks initially respond only to moving stimuli, but with repeated exposure will be comforted by a stationary stimulus. • They follow it around due to sign tracking. • The imprinted stimulus (train) can calm an upset duck but causes distress when removed, even if the duck is already calm. • The distress is the b-process in attachment.

17. Effects of Repeated Exposure • Ducks become more attached to an imprinted stimulus after repeated exposures. • Exposures must be massed (spaced close together in time). • A single long exposure produces a distress-calling after-reaction. • This is contrary to other classical conditioning situations, where massed exposure is worse.

18. Drug Addictions • Withdrawal symptoms seem to be an opponent-process elicited by a CS associated with the drug (S*). • The CR is the b-process and it offsets the body’s response to the drug itself. • The opponent process appears to be learned, not innate. • It is problematic for the learning explanation that the b-process increases with massed exposure.