PSY402 Theories of Learning

1. PSY402Theories of Learning Chapter 6 (Cont.) Chapter 8 – Cognitive Theories

2. Criticisms of Contiguity Theory • Guthrie conducted few studies to support his theory. • Accurate parts: • Punishment can intensify inappropriate behavior when it elicits a response compatible with the punished response. • Contiguity is essential to prevent conditioning of competing associations. • Not all environmental cues are noticed.

3. Impact of Reward • Guthrie’s view of reward has been disproved. • If what happens after a response is not rewarding, an S-R association is not formed, even if the stimulus changes. • Noble – reward size predicts response better than recency or frequency (contiguity measures).

4. Single-Trial Learning • All-or-nothing (single-trial) learning has been difficult to demonstrate. • Voeks – found single-trial learning of an eye-blink response in humans. • Other studies report gradual learning. • Spence proposed a threshold explanation of single-trial learning using incremental learning theory.

5. Skinner • Emphasized the importance of environment (reinforcers & contingencies). • Validation of hypothetical constructs interferes with analysis of the variables controlling behavior. • Anti-theory

6. Spence’s Acquired Motives • Spence was a colleague of Hull. • Spence elaborated the idea that reward size matters (K in Hull’s theory). • It isn’t enough to say that reward size matters – how specifically does it affect behavior? • Spence proposed a mechanism.

7. Goal Responses • Reward elicits an unconditioned goal response RG. • This response produces an internal stimulus state SG that motivates consummatory behavior. • Reward value determines the size of the goal response RG.

8. Anticipatory Goal Responses • Cues become associated with reward through classical conditioning. • These produce an anticipatory goal response rG. • Cues lead to internal stimulus changes sG that motivate behavior. • Thus Pavlovian conditioning motivates approach behaviors.

9. Amsel’s Frustration Theory • Amsel applied Spence’s theory to avoidance of aversive events: • Frustration motivates avoidance. • Frustration suppresses approach. • Nonreward produces unconditioned frustration response RF. • The stimulus associated with it SF motivates escape behavior.

10. Anticipatory Frustration Response • As with goal states, classical conditioning results in anticipatory frustration response rF. • The conditioned stimuli associated with them sF motivate avoidance of a frustrating situation. • Example: car that won’t start. • SF motivates leaving the car, sF motivates selling it.

11. Mowrer’s Two-Factor Theory • Mowrer proposed a drive-based two-factor theory to avoid explaining avoidance using cognitive (mentalistic) concepts. • Avoidance involves two stages: • Fear is classically conditioned to the environmental conditions preceding an aversive event. • Cues evoke fear -- an instrumental response occurs to terminate the fear.

12. Mowrer’s View (Cont.) • We are not actually avoiding an event but escaping from a feared object (environmental cue). • Miller’s white/black chamber – rats escaped the feared white chamber, not avoided an anticipated shock. • Fear reduction rewards the escape behavior.

13. Criticisms of Two-Factory Theory • Avoidance behavior is extremely resistant to extinction. • Should extinguish with exposure to CS without UCS, but does not. • Levis & Boyd found that animals do not get sufficient exposure duration because their behavior prevents it. • Avoidance persists if long latency cues exist closer to the aversive event.

14. Is Fear Really Present? • When avoidance behavior is well-learned the animals don’t seem to be afraid. • An avoidance CS does not suppress operant responding (no fear). • However, this could mean that the animal’s hunger is stronger than the fear. • Strong fear (drive strength) is not needed if habit strength is large.

15. Avoidance without a CS • Sidman avoidance task – an avoidance response delays an aversive event for a period of time. • There is no external cue to when the aversive event will occur – just duration. Temporal conditioning. • How do animals learn to avoid shock without any external cues for the classical conditioning of fear?

16. Kamin’s Findings • Avoidance of the UCS, not just termination of the CS (and the fear) matters in avoidance learning. • Four conditions: • Response ends CS and prevents UCS. • Reponse ends CS but doesn’t stop UCS. • Response prevents UCS but CS stays. • CS and UCS, response does nothing (control condition).

17. D’Amato’s Acquired Motive View • D’Amato proposed that both pain and relief motivate avoidance. • Anticipatory pain & relief responses. • Shock elicits unconditioned pain response RP and stimulus SP motivates escape. • Classically conditioned cues sP elicit anticipatory pain response rP that motivates escape from the CS.

18. Anticipatory Relief Response • Termination of the UCS produces an unconditioned relief response RR with stimulus consequences SR. • Conditioned cues elicit an anticipatory relief response rR with stimulus consequences sR. • Example: dog bite elicits pain response, sight of dog elicits anticipatory pain, house elicits relief

19. A Discriminative Cue is Needed • During trace conditioning no cue is present when UCS occurs and no avoidance learning occurs. • A second cue presented during avoidance behavior slowly acquires rR-sR conditioning. • Similarly, in a Sidman task, cues predict relief -- associated with avoidance behavior, not the UCS.

20. How is rG Measured? • Anticipatory goal responses were initially measured as peripheral nervous system (ANS) response. • No consistent relationship between such measures and behavior could be found. • Now, Rescorla & Solomon propose that these anticipatory states are due to CNS activity (brain states).

21. PSY402Theories of Learning Chapter 8 – Cognitive Theories

22. Purposive Behaviorism • Tolman – behavior is goal-oriented. • Through experience we gain expectations about how to use paths and tools to achieve goals. • We expect specific outcomes to follow specific behaviors. • If unrewarded, we seek other ways to accomplish our goals.

23. Tolman’s View (Cont.) • We do not have to be reinforced in order to learn. • We must be motivated: • Motivation produces internal tension creating a demand for the goal. • Motivation determines what features of the environment will be noticed. • Behavior is not fixed, automatic or stereotyped, but flexible.

24. Place-Learning Studies • Demonstrate existence of spatial expectations. • T-Maze – rat starts at different location but reward always in same end of maze. • Rats must turn different directions. • Alternate-path maze – rats choose the shortest path after learning. • When blocked, take next shortest path.

25. Latent-Learning Studies • Investigate whether reward is necessary for learning to occur. • Three conditions: • R –always got reward at goal • NR –never got reward at goal • NR-R – rewarded only on last 10 days • NR-R rats show rapid decrease in errors when rewarded -- motivation is needed for performance.

26. Problems with Latent-Learning • Difficulty replicating results: • MacCorquodale & Meehl found 30 of 48 studies could reproduce the results. • Motivation restricts attention to relevant cues. Irrelevant rewards are ignored. • No latent learning occurs when strong but irrelevant rewards are provided, even if they are relevant later.

27. Drive Response • Consistent latent learning occurs when rats are not deprived initially. • Spence’s anticipatory goal response, rG-sG was created to explain this result. • The anticipatory goal response is formed but not apparent until there is deprivation to activate the goal. • Handling animals may have been a reward for Tolman’s NR-group.

28. Expectancies • Expectancy –mental representation of event contingencies. • Dickinson – an expectancy contains two kinds of information: • Associative link between two events – classically conditioned, mechanistic. • Behavior-reinforcer belief – consequences of action, operant, intentional.

29. Testing Associative Links • Two groups trained to bar press: • One group reinforced with sodium (Na) • Other group reinforced with potassium (K) • Both tested when deprived of sodium. • Irrelevant incentive effect – sodium deprivation activated associative link for Na rats but not K rats. • Could be due to beliefs not links.

30. Testing for Beliefs • Reinforcer devaluation effect – what happens if the reinforcer is diminished in value after training? • One group got sucrose for bar-pressing and food regardless of behavior. • Other group got food for bar-pressing and sucrose non-contingently. • Sucrose devalued during testing. • Bar pressing was lower when the sucrose was behavior-contingent.

31. Importance of Disgust • Devaluation is a two-stage process: • A disgust reaction is associated with the reinforcer (devalued by illness). • The reinforcer must be reexperienced. • Devaluation of the reinforcer occurs when reexperience activates the associated disgust. • Studied using ondansetron – a strong anti-emetic (reduces nausea).

32. Importance of Habits • Dickinson acknowledged that habits do exist and can control behavior. • Expectancies (behavior-reinforcer beliefs) control actions before habits are established. • Behavioral autonomy – control of responding by habit rather than expectancy. • Habit responds to devalued reinforcer.