Operant Conditioning Type of learning in which the frequency of a behavior depends on the consequence that follows that behavior. Another form of learning through association. Different from Classical Conditioning: Classical Conditioning Focus = involuntary behaviors Operant Conditioning Focus = voluntary behaviors

Edward L. Thorndike Studied the effects of consequences on the behavior of cats Columbia University 1890’s

The Puzzle Box Cats were placed in the puzzle box. If they pulled a string that dangled from the top of the box a latch would be released allowing the cat to escape the box & reach a bowl of food

The Law of Effect Behaviors that lead to satisfying consequences will be strengthened & are likely to be repeated. Behaviors that lead to unsatisfying consequences will be weakened & are unlikely to be repeated. Called the whole process instrumental learning

B. F. Skinner Built upon Thorndike’s theories Introduced the concepts of: “reinforcement” & “punishment”

Reinforcement Anything that increases the frequency of the behavior it follows Increases the likelihood of the behavior occurring again Reinforcers strengthen behavior

Reinforcement Examples:

Positive Reinforcement The frequency of a behavior increases because it is followed by a pleasant stimulus “reward” Positive = ADDITION + Something good is added Getting a kiss for doing the dishes.

Negative Reinforcement The frequency of a behavior increases because an unpleasant stimulus is removed as a result “relief” Negative = SUBTRACTION – The behavior continues because it removes or ends something that is unpleasant

Two types of Negative Reinforcement 1.Escape Learning Allows the subject to terminate an aversive stimulus Ex/Getting kicked out of a class that you don’t like 2. Avoidance Learning Allows the subject to avoid an aversive stimulus altogether. Ex/ Cutting class that you don’t like

Punishment Anything that decreases the frequency of the behavior it follows Decreases the likelihood of the behavior occurring again Punishers weaken behaviors

Punishment Examples:

Positive Punishment The frequency of a behavior decreases because an aversive, unpleasant stimulus is presented as a result Positive = ADDITION + Something bad is added

Negative Punishment (sometimes called Omission Training) The frequency of a behavior decreases because a pleasant stimulus is removed as a result Negative = SUBTRACTION – You lose something that you want Something good is taken away

Operant Conditioning Processes Generalization: A behavior that has been reinforced in the presence of one stimulus will also occur in the presence of similar stimuli A behavior that has been punished in the presence of one stimulus will NOT occur in the presence of similar stimuli

Operant Conditioning Processes Discrimination: Behaviors that have been reinforced will occur in the presence of one stimulus but NOT in the presence of similar stimuli

Operant Conditioning Processes Extinction: The weakening & eventual disappearance of a conditioned behavior Occurs when a conditioned behavior is no longer reinforced – becomes less frequent & eventually disappears

Operant Conditioning Processes Spontaneous Recovery: The sudden reappearance of an extinguished behavior with no retraining

Operant Conditioning Processes Shaping: The process of teaching a complex behavior by rewarding closer & closer approximations of the desired behavior You reinforce every behavior that takes the subject a little closer to the target behavior Successive approximations

Chaining Behaviors Subjects are taught a number of responses successively in order to get a reward.. Whereas the goal of shaping is to mold a single behavior, the goal of chaining is to link several separate behaviors into a more complex activity

Primary v. Secondary Reinforcers Primary Reinforcer Things that are in themselves rewarding. Secondary Reinforcer Things we have learned to value. Money is a special secondary reinforcer called a generalized reinforcer (because it can be traded for just about anything)

Schedules of Reinforcement 1.Continuous Reinforcement: Reinforcement every time the desired behavior occurs Most effective way to ESTABLISH a new behavior 2. Partial Reinforcement: Behavior = reinforced some but not all of the time Once a behavior has been established this is the best way to MAINTAIN it Delays extinction

Comparing Reinforcement Schedules CONTINUOUS REINFORCEMENT: Vending Machine PARTIAL REINFORCEMENT: Slot Machine

Schedules of Reinforcement: Partial Schedules KEY TERMS: Fixed = the same every time, “set” Variable = different every time, “varies” Ratio = counting responses reinforcement occurs after a certain number of correct behaviors Interval = the passage of time reinforcement occurs after a certain amount of time has gone by

Schedules of Reinforcement: Partial Schedules 1.Fixed-ratio schedule: Reinforcement after a fixed number of behaviors

Schedules of Reinforcement: Partial Schedules 2. Variable-ratio schedule: Reinforcement after a varying number of behaviors

Schedules of Reinforcement: Partial Schedules 3. Fixed-interval schedule: Reinforcement of the first response after a fixed amount of time has passed

Schedules of Reinforcement: Partial Schedules 4.Variable-interval schedule: Reinforcement of the first correct behavior after varying amounts of time pass