PSY 402 Theories of Learning Chapter 7 Behavior

PSY 402 Theories of Learning Chapter 7 – Behavior & Its Consequences Instrumental & Operant Learning

Two Early Approaches o Reinforcement Theory n n o Thorndike’s “Law of Effect” for cats in the puzzle box. Skinner boxes – rats pressing bars Contiguity Theory n n Guthrie – association is enough Estes – Stimulus Sampling Theory

Problems with Contiguity Theory o o Guthrie proposed that no reinforcement was needed – just contiguity (closeness) in time and place. If learning is immediate and one-trial, why are learning curves gradual? n o Only a few stimulus elements are associated on each trial, but more build up with each trial. His view was wrong but influential (Estes).

Guthrie & Reinforcement o o The reinforcer is salient, so it changes the stimulus (environmental situation). Reward keeps competing responses from being associated with the initial stimulus. n o Competing responses are instead associated with the presence of the reward. Fixity of cat flank-rubbing supported Guthrie but was later shown to be related to the presence of the experimenter instead.

Tolman’s Operational Behaviorism o His theories relied on “intervening variables” not mechanistic S-R associations. n n o Behavior is motivated by goals. Behavior is flexible, a means to an end. Rats in mazes form cognitive maps of their environment. n Animals learn about stimuli, not just behavior.

Evidence of Cognitive Maps o Changing the maze layout resulted in running toward the same “goal. ” n o A light could have been used as a cue in both situations. Using a “plus maze, ” some rats were trained to always turn a certain direction, while others were trained to reach a consistent place. n The consistent place was easier to learn.

Latent Learning o Rats were given experience in a complex maze, without reward. n n o Later they were rewarded for finding the goal box. Performance (number of errors) improved greatly with reward, even among previously unrewarded rats. Reward motivates performance, not learning.

Skinner’s Contribution o o o Skinner was uninterested in theory – he wanted to see how learning works in practice. Operant chambers permit behaviors to be repeated as often as desired – more voluntary. Superstitious behavior – animals were rewarded at intervals without regard to their behaviors. n Animals related whatever they were doing to the reward, and wound up doing odd things.

Stimulus Control o Skinner discovered that stimuli (cues) provide information about the opportunity for reinforcement (reward). n o o The stimulus sets the occasion for the behavior. Fading – gradually transferring stimulus control from a simple stimulus to a more complex one. Operant behavior is controlled by both stimuli and reinforcers.

Discriminative Stimuli o o o Discriminative stimuli act as “occasion setters” (see Chap 5) in classical conditioning. The stimulus that signals the opportunity for responding and gaining a reward is SD. The stimulus that signals the absence of opportunity is SD.

Types of Reinforcers o Primary reinforcer – stimuli or events that reinforce because of their intrinsic properties: n o Food, water, sex Secondary reinforcer – stimuli or events that reinforce because of their association with a primary reinforcer: n n Money, praise, grades, sounds (clicks) Called conditioned reinforcers.

Behavior Chains o o o Secondary (conditioned) reinforcers reward intermediate steps in a chain of behavior leading to a primary reinforcer. Secondary reinforcers can also be discriminative stimuli that set the occasion for more responding. Classical conditioning is a glue that enables chains of behavior leading to a goal.