OPERANT CONDITIONING DEF A FORM OF LEARNING IN

OPERANT CONDITIONING DEF: A FORM OF LEARNING IN WHICH RESPONSES COME TO BE CONTROLLED BY THEIR CONSEQUENCES

THORNDIKE’S LAW OF EFFECT • Edward L. Thorndike • Studied instrumental learning • This is the foundation of operant conditioning • Cat studies

LAW OF EFFECT • DEF: if a response in the presence of a stimulus leads to a satisfying effects, the association between the stimulus and the response is strengthened • The cornerstone of B. F. Skinner’s theory

SKINNER’S DEMONSTRATION • Skinner showed that organisms tend to repeat those responses that are followed by favorable consequences • Reinforcement: occurs when an event following a response increases an organism’s tendency to make that response

TERMINOLOGY • Operant chamber: “Skinner Box”, a small enclosure in which an animal can make a specific response that is recorded while the consequences of the response are systematically controlled • Used to control Reinforcement contingencies: rules that determine whether response lead to the presentation of reinforcers

OPERANT CONDITIONING • Key dependent variable is subject’s response rate over time • Cumulative recorder: creates a graphic record of responding and reinforcement in a Skinner box as a function of time

BASIC PROCESSES OF OPERANT CONDITIONING • Shaping: the reinforcement of closer and closer approximations of a desired response • Important in acquisition • Necessary when an organism does not emit the desired response

BASIC PROCESSES OF OPERANT CONDITIONING • Extinction: weakening and disappearance of a response tendency b/c the response is no longer followed by a reinforcer • Resistance to extinction: when an organism continues to make a response after delivery of the reinforcer for it has been terminated

DISCRIMINATIVE STIMULI • DEF: cues that influence operant behavior by indicating the probable consequences of a response • Regulate operant behavior

STIMULUS GENERALIZATION/DISCRIMINATION • Generalization: Responding to a new stimulus as if it were the original • Stimulus discrimination: decrease in response to a new stimulus that resembles the original

REINFORCEMENT • Strengthening of a response tendency • Defined after the fact, in terms of effect on behavior • Reinforcement is subjective

DELAYED REINFORCEMENT • Favorable outcomes are more likely to strengthen a response if the outcome follows immediately

CONDITIONED REINFORCEMENT • Primary reinforcers: events that are inherently reinforcing b/c they satisfy biological needs • Secondary (conditioned) reinforcers: events that acquire reinforcing qualities by being associated w/primary reinforcers

INTERMITTENT REINFORCEMENT: EFFECTS OF BASIC SCHEDULES • Schedule of reinforcement: determines which occurrences of a specific response result in the presentation of a reinforcer

INTERMITTENT REINFORCEMENT • Continuous reinforcement: occurs when every instance of a designated response is reinforced • Intermittent, partial, reinforcement: occurs when a designated response is reinforced only some of the time • Intermittent makes a response more resistant to extinction • There are 4 types of intermittent reinforcement…

FIXED-RATIO (FR) SCHEDULE • Ratio schedules require the organism to make a response a certain amount of times to gain a reinforcer • FR Schedule: the reinforcer is given after a fixed number of nonreinforced responses

VARIABLE-RATIO (VR) SCHEDULE • The reinforcer is given after a variable number of nonreinforced responses

FIXED-INTERVAL (FI) SCHEDULE • Interval schedules require a time period to pass btwn presentation of reinforcers • FI Schedule: the reinforcer is given for the 1 st response that occurs after a fixed time interval has elapsed

VARIABLE-INTERVAL (VI) SCHEDULE • The reinforcer is given for the 1 st response after a variable time interval has elapsed • Interval length depends on a predetermined avg.

RATIO VS. INTERVAL • Ratio schedules produce more rapid responding • Variable schedules tend to generate steadier response rates and greater resistance to extinction

CONCURRENT SCHEDULES OF REINFORCEMENT • Concurrent schedules of reinforcement: consist of 2 or more reinforcement schedules that operate simultaneously and independently, each for a different response

MATCHING LAW • States that under concurrent schedules of reinforcement, organisms’ relative rate of responding to each alternative tends to match each alternative’s relative rate of reinforcement • Quality of reinforcement earned also effects response rate • Assumes organisms are working to maximize their overall reinforcement

MATCHING AND FORAGING • Optimal foraging theory: food seeking behaviors of many animals maximize the nutrition gained in relation to the energy expended to locate, secure, and consume various foods

POSITIVE REINFORCEMENT • Occurs when a response is strengthened b/c it is followed by the presentation of a rewarding stimulus

NEGATIVE REINFORCEMENT • Occurs when a response is strengthened b/c it is followed by the removal of an aversive stimulus • Don’t be confused by word negative • Many everyday behaviors effected by negative reinforcement

ESCAPE LEARNING • Def: an organism acquires a response that decreases or ends some aversive stimulation • Shuttle box

AVOIDANCE LEARNING • DEF: an organism acquires a response that prevents some aversive stimulation from occurring • Avoidance learning responses are very resistant to extinction

TWO-PROCESS THEORY OF AVOIDANCE • Avoidance begins b/c classical conditioning creates a conditioned fear • Avoidance is maintained by operant conditioning • Avoidance response is strengthened through negative reinforcement

PUNISHMENT: CONSEQUENCES THAT WEAKEN RESPONSES • Punishment occurs when an event following a response weakens the tendency to make that response • NOT NEGATIVE REINFORCEMENT!!!

PUNISHMENT • Can have side effects: • General suppression of behavioral activity • Trigger strong emotional responses • Physical punishment often leads to aggressive behavior • More effective to reinforce desirable behavior than punish undesirable behavior