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Operant Conditioning. AKA Pigeons in Cages. What is Operant Conditioning? It’s how a dog learns to sit on command It’s how you learned to drive a car It’s how you learned to make friends
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Operant Conditioning AKA Pigeons in Cages
What is Operant Conditioning? It’s how a dog learns to sit on command It’s how you learned to drive a car It’s how you learned to make friends Operant Conditioning studies voluntary responses, where Classical Conditioning studies elicited responses. Operant Conditioning: Learning Through Consequences
Thorndike’s Law of Effect • 1898- Edward Thorndike studies how animals solve problems. • Because performance improvement was solved, Thorndike concluded that animals do not gain insight into the problem. • Instrumental learning: behavior is instrumental in bringing about an outcome • Law of effect: in a given situation, a response followed by a satisfying consequence will become more likely to occur and a response followed by an annoying consequence will become less likely to occur
B.F. Skinner • Coined the term Operant Conditioning • type of learning in which behavior is influenced by the consequences that follow it • Known for the “Skinner Box”
B.F. Skinner Primary Types of Consequences: • Reinforcement: response is strengthened by an outcome that follows it • Example A: rat receives food when he presses the lever, increasing the chance that he will press the lever • Punishment: occurs when a response is weakened by outcomes that follow it • Example A: rat receives a small electric shock when he presses the lever, decreasing the chance that he will press the lever
B.F. Skinner • Three-Part Contingency: • IF antecedent stimuli are present • IF I say, “Sit!” • AND behavior is emitted • AND my dog Sheila sits, • THEN consequences will occur • THEN Sheila will receive a treat. • The consequence of receiving food is contingent upon Sheila’s response of sitting.
Identifying When to Respond • Discriminative Stimuli signal that a particular response will now produce certain consequences. • Back the rat: If pressing the lever dispenses food only when a light is on, the rat will quickly learn to press the lever only when the light is on.
Consequences: Positive Reinforcement • Occurs when a response is strengthened by the subsequent presentation of a stimulus • Rat receives food pellets when it presses the lever, and begins to press it more often • A new employee receives praise for completing a small project quickly, and so completes more of her projects on time • A volunteer receives donations, praise from her fellow workers, and feelings of pride in helping others, and so can keep going despite adverse conditions
Consequences:Positive Reinforcement • Primary Reinforcers: stimuli that an organism naturally finds reinforcing because they satisfy a biological need (food, water, etc.) • Secondary Reinforcers: stimuli that acquire reinforcing properties through their association with primary reinforcers (money, praise)
Consequences:Negative Reinforcement • A response is strengthened by the subsequent removal of an aversive stimulus • NOT PUNISHMENT! • Example A: • Your alarm clock goes off. • You hit the ‘snooze’ button. • Annoying ringing stops. • Example B: • Your mom nags you to clean your room. • You clean your room. • Mom stops nagging you.
Operant Extinction • The weakening and eventual disappearance of a response because it is no longer reinforced. • Often used as an alternative to punishment in attempting to reduce undesirable behaviors. • Mrs. Adams sought help at a child guidance clinic because her 5-year-old son, Jonathan, delighted in misbehaving. She had tried to reason with him. Then she resorted to yelling. Finally, she began spanking him. Even that did not work. • Psychologist’s advice: Ignore him when he misbehaves. Pay attention when he acts appropriately. He is actually after attention, and she is awarding it (though it’s not pleasant, it’s still attention).
Consequence:Aversive Punishment • Or Punishment by application, or positive punishment • Response is weakened by the subsequent presentation of a stimulus • Spanking • Child touching a hot burner
Consequence: Response Cost • Taking away something that satisfies the individual • A response is weakened by the subsequent removal of a stimulus • Time-out (kids or hockey players) • Speeding ticket fine
Shaping and Chaining • Shaping: reinforcing successive approximations toward a final response • Reinforcing performance of the ‘next step’ in a sequence, but not performance of the previous step • Chaining: developing a sequence of responses by reinforcing each response with the opportunity to perform the next response • The rat has learned to press a lever for food when the light comes on. We place a bell in his cage. Eventually, he bumps into it and the bell rings, turning on the light. The rat sees the light, presses the lever, and receives food. Over time, the rat will learn to ring the bell because the response is reinforced by the light turning on, which provides the opportunity to press the lever for food.
Generalization and Discrimination • Operant generalization: an operant response occurs to a new antecedent stimulus or situation that is similar to the original • Lassie responds to the “sit” command, even when it is given by someone other than her owner. • Operant discrimination: the operant response will occur to one antecedent stimulus, but not to another • Upon seeing a police car, you slow down, but you do not do so upon seeing just any car.
Schedules of Reinforcement • Reinforcement comes in different patterns, referred to as schedules. • Continuous reinforcement: every response of a particular type is reinforced. • Every time you put $1.25 into the soda machine, you get a bottle of soda. • Partial reinforcement: only a portion of the responses of a particular type are reinforced. • Powerful motivators
Schedules of Reinforcement:Partial Reinforcement • Fixed-ratio schedules: reinforcement occurs after a fixed number of responses • FR-3 reinforcement occurs after every third response • Variable-ratio schedules: reinforcement occurs after a variable number of responses, centered around an average • The gambler plays a slot machine programmed to pay off an average of every 20 pulls. After 8 pulls, he receives a 10-coin jackpot. After 2 more pulls, he receives a 15-coin jackpot. But, after 30 more attempts, nothing. He’s frustrated, but still stuck in the VR cycle. That next attempt might just pay off... Or the next… or the next….
Schedules of Reinforcement:Partial Reinforcement • Fixed-Interval Schedule: the first response that occurs after a fixed time interval is reinforced • After the rat presses a lever, he must wait 2 minutes before another response will occur, regardless of how many times he hits the lever. • Variable-Interval Schedule • Reinforcement is given for the first response after a variable time interval, centered around an average. • Pop quizzes, random drug testing, roadside speed traps
Escape and Avoidance Conditioning • Escape conditioning: the organism learns a response to terminate an aversive stimulus • Acquired and maintained by negative reinforcement • If you’re cold, putting on a sweater is negatively reinforced by the desirable consequence that you no longer shiver. • Avoidance conditioning: the organism learns a response to avoid an aversive condition • We dress warmly to avoid feeling cold in the first place.
Two-Factor Theory of Avoidance Learning • Classical and Operant conditioning work together to achieve avoidance learning. • Carol’s fear of cars is classically conditioned. • The sight of a car elicits fear and causes her to flee, thereby avoiding riding in cars. • The avoidance is negatively reinforced by fear reduction, so it remains strong. • Extinction (without therapy) is difficult because she does not allow herself the opportunity to be in the car without experiencing pain and fear. • Exposure therapy works by preventing avoidance.
Speaking of Classical Conditioning… • Classical and Operant Conditioning can operate together… and frequently do. • Example: A teacher has a talent for making chalk squeak on a chalkboard. Eventually, seeing him raising the chalk to the chalkboard will become a CS that automatically triggers a CR of shivers up the spine. It also becomes a signal for the students to cover their ears (an operant response) which is reinforced by the consequence of reducing the squeaking sound. • Ta Da! One stimulus has classical and operant functions!
