Operant Conditioning E.L. Thorndike and B.F. Skinner

Operant Conditioning A. At the same time that Pavlov (and later Watson) was experimenting with what was to be known as “Classical” conditioning, E.L. Thorndike was experimenting with “Operant” conditioning or “Instrumental” Conditioning. His research served as the basis for B.F. Skinner’s research.

Operant Conditioning Clip Law of Effect Thorndike’s principle that: 1.Behaviors followed by favorable consequences become more likely 2.Behaviors followed by unfavorable consequences become less likely *Puzzle Box

Early Operant Conditioning zE. L. Thorndike (1898) zPuzzle boxes and cats Scratch at bars Push at ceiling Dig at floor Situation: stimuli inside of puzzle box Howl Etc. Press lever First Trial in Box Scratch at bars Push at ceiling Dig at floor Situation: stimuli inside of puzzle box Howl Etc. Press lever After Many Trials in Box

Edward L. Thorndike ( 1874–1949)

Operant Conditioning  B.F. Skinner ( )  elaborated Thorndike’s Law of Effect  developed behavioral technology

B. F. Skinner (1904–1990)

Operant Conditioning  Operant Conditioning  type of learning in which behavior is strengthened if followed by reinforcement or diminished if followed by punishment *Instrumental because you use an “instrument” (reinforcement or punishment) to shape behavior.

Operant Conditioning  Operant Behavior  operates (acts) on environment  produces consequences  Respondent Behavior  occurs as an automatic response to stimulus  behavior learned through classical conditioning

Operant Chamber  Skinner Box  chamber with a bar or key that an animal manipulates to obtain a food or water reinforcer  contains devices to record responses

zWhat is the instrument? zWhat behavior is strengthened?

Types of Conditioning Instruments Positive (Stimulus is Given) Negative (Stimulus is Removed) Reinforcement (Increases Desired Behavior) Give Something Increase Behavior Remove Something Increase Behavior Punishment (Decreases Undesirable Behavior) Give Something Decrease Behavior Remove Something Decrease Behavior Instruments of Conditioning

Our Class: zExperiment 1: yWhat is the instrument? zExperiment 2: yWhat is the instrument? zWhich worked best?

Operant Conditioning

Classroom Practice Sheldon Choc 1.mp4 Sheldon Choc 2.mp4 Sheldon Choc 3.mp4 1.What is the desired behavior? 2.What is the instrument? Zi-U

In shaping, successively closer versions of a desired response are reinforced (as in learning to play tennis). In chaining, each part of a sequence is reinforced; the different parts are put together into a whole (as in learning the steps to a dance). Operant Conditioning

Punishment  Punishment  aversive event that decreases the behavior that it follows  powerful controller of unwanted behavior

Punishment

Problems with Punishment Does not teach or promote alternative, acceptable behavior May produce undesirable results such as hostility, passivity, fear Likely to be temporary May model aggression

Operant Conditioning Processes Primary Reinforcement is unlearned and usually necessary for survival. Food is the best example of a primary reinforcer. Secondary Reinforcement is anything that comes to represent a primary reinforcer such as praise from a friend or a gold star on a homework assignment. Also called conditioned reinforcer.

Common Terminology Classical Acquisition – repeatedly pair CS with UCS Extinction – CS no longer paired with UCS, CR extinguished Spontaneous Recovery – After period of extinction, CR returns in presence of CS Generalization – Will respond to stimuli similar to CS Discrimination – Will ONLY respond to CS Operant Acquisition – behavior repeatedly FOLLOWED BY reinforcement/punishment Extinction – behavior no longer reinforced/punished so extinguished Spontaneous Recovery – behavior suddenly reappears (after extinguished) in presence of reinforcer Generalization – will respond to reinforcement/punishment similar to original Discrimination – will ONLY respond to original reinforcement/punishment

Schedules of Reinforcement  Immediate Reinforcers  To our detriment, small but immediate reinforcements are sometimes more alluring than big, but delayed reinforcements  Continuous Reinforcement  reinforcing the desired response each time it occurs  Partial (Intermittent) Reinforcement  reinforcing a response only part of the time  results in slower acquisition  greater resistance to extinction

Schedules of Reinforcement  Fixed Ratio (FR)  reinforces a response only after a specified number of responses  faster you respond the more rewards you get  different ratios  very high rate of responding  like piecework pay

Schedules of Reinforcement  Variable Ratio (VR)  reinforces a response after an unpredictable number of responses  average ratios  like gambling, fishing  very hard to extinguish because of unpredictability

Schedules of Reinforcement  Fixed Interval (FI)  reinforces a response only after a specified time has elapsed  response occurs more frequently as the anticipated time for reward draws near

Schedules of Reinforcement  Variable Interval (VI)  reinforces a response at unpredictable time intervals  produces slow steady responding  like pop quiz