PSY402 Theories of Learning Chapter 6 (Cont.) Chapter 8 – Cognitive Theories

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.

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).

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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?

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).

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.

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

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.

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).

PSY402 Theories of Learning Chapter 8 – Cognitive Theories

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.

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.

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.

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.

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.

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.

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.

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.

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.

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).

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.