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 1st response that occurs after a fixed time interval has elapsed

VARIABLE-INTERVAL (vi) SCHEDULE The reinforcer is given for the 1st 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