Welcome! Please write down your homework: –Test next class. Ch. 8 and all review chapters –Notecards due next class

Operant Conditioning

Introduction Classical Conditioning= an organism associates different stimuli that it does not control. Operant Conditioning= the organism associates its behaviors with consequences. Behaviors followed by reinforcements increase; those followed by punishers decrease.

Operant means… ….Explain and train

Operant Conditioning A type of learning in which responses can be controlled by their consequences i.e. rewards or punishments

Reward vs. Punishment Reward = more likely behavior will repeat Punishment = less likely to repeat behaviors

Behavior Respondent Behavior –Behavior that occurs as an automatic response to some stimulus Ex: food when hungry; water when thirsty Operant Behavior –The act operates on the environment to produce rewarding or punishing stimuli Ex: good grades = MONEY; bad grades = grounded

Important People in Operant Conditioning

B.F. Skinner Edward Thorndike Radical Behaviorism Skinner Box Puzzle Box Law of Effect

Skinner Operant Chamber- –“Skinner Box” –Soundproof –Bar or key that an animal presses or pecks to release a rewards of food or water –Device that records these responses Shaping- - Procedure in which reinforcers (like food) gradually guide an animal’s actions toward a desired behavior

Edward L. Thorndike Law of Effect: –Rewarded behavior is likely to reoccur –Puzzle Box

Operant Conditioning Chamber Skinner Box Puzzle Box

Two important concepts used in Operant Conditioning Reinforcer - (Positive and Negative)Reinforcer - (Positive and Negative) increases –A stimulus or event that increases the odds of repeating the behavior that led to it I give my kids money when they clean their room…this stimulus increases the odds they will do it again PunisherPunisher –A stimulus or event that functions to decreases the odds of repeating the behavior that lead to I spank my kids when they throw food at the dinner table…this event decreases the odds they will do it againRemember… –It is often the learner that determines if something is a reinforcement or punishment Premack Principle –This is called the Premack Principle Example: I might give Ryan broccoli after he did a chore and if he likes it he will do more chores or I might give Ryan broccoli after he did a chore and he may never do that chore again. My feelings toward broccoli make no difference

Reinforcer Two Types of Reinforcement: Positive and Negative Anything likely to increase a behavior

Positive Reinforcement added (reinforces)Something desirable is added to the environment and this encourages (reinforces) behavior –Behaviors are strengthened when they are followed by the introduction of a stimulus A

Negative Reinforcement subtracted (reinforces)Something undesirable is subtracted from the environment and this encourages (reinforces) behavior –NR are aversive stimuli such as loud noise, cold, pain, or nagging We are more likely to repeat behaviors that lead to their removal –Example Say I have a headache The NR is the pain of the headache I take aspirin and the headache goes away Headache pain (stimulus) - - aspirin (response) - - consequence (headache gone) I will take aspirin again because it removed something unpleasant So…positive and negative do not mean good or bad. Instead, positive means adding a stimulus, and negative means removing a stimulus.

Types of Reinforcers

Primary Reinforcers- reinforcements that happen naturally; not learned (i.e. getting food when hungry, taking your hand off a burning stove to relieve pain) Conditioned Reinforcers- (secondary reinforcers) are learned. (i.e. if a rat in Skinner’s box learns that when a light signal goes off it signals food, the light becomes on the secondary reinforcer

Primary Reinforcer Things that are in themselves rewarding and satisfy biological needs Like food, warmth, or water

Secondary (or Conditioned) Reinforcer Something that you have learned to value through classical conditioning –Money, fines or grades Secondary reinforcers can loose their effectiveness

Reinforcement Schedules The pattern (schedule) in which reinforcement (reward or punishment) is given. These schedules influence learning

Continuous Reinforcement Reinforcing the desired response every time it occurs. –Example – vending machine Quick Acquisition Quick Extinction

Partial Reinforcement Reinforcing a response only part of the time.Reinforcing a response only part of the time. –slot machine –You don’t expect to win every time but hope to win sometime –The acquisition process is slower, but… –Greater resistance to extinction. 4 different partial reinforcement schedules time(interval schedule) –Two focus on time between reinforcement (interval schedule) number (ratio schedule) –Two focus on number of responses between reinforcement (ratio schedule)

Fixed-Interval Schedule time (interval)Reinforcement of a behavior after a specified or fixed time (interval) has passed. You get paid every two weeks A worker gets a bonus once a year –After receiving a reward (a reinforcement) the worker has to wait one year for another reward (fixed interval)

Variable-interval Schedule timeReinforcement of a behavior at unpredictable (variable) time intervals. You don’t know when the reinforcement is coming so you keep trying or have to be prepared to take action Pop Quizzes

Fixed-ratio Schedules numberReinforcement of a behavior only after a specified (fixed) number of responses Movie rentals that say rent 5 get one free A worker gets a bonus after every three items he sells

Variable-ratio Schedule numberReinforcement of a behavior after an unpredictable (variable) number of responses. –Working on sales commission gambler’s scheduleSometimes called the gambler’s schedule –Back to the lottery… –You don’t know when you will win but you do know the more you buy the better your chances

Overjustification Effect When external rewards undermine the intrinsic satisfaction of performing a behavior –Makes people only do something for reward or prize and not for pure joy –Usually the reward may lesson and replace the person’s original, natural motivation so that the behavior stops if the reward is eliminated Pizza for reading –“what, I don’t get a free pizza for reading 10 books?”

Punishment Flip side of reinforcement The introduction of a bad stimulus or the removal of a reinforcing stimulus after a response occurs –Weakens a behavior or makes it less likely to occur again in the future Does punishment work? Yes, but… Often tells the learner what behavior should NOT be exhibited and not what behavior should be And…don’t forget the Premack Principle

Difference between Negative Reinforcement and Punishment  Punishment the introduction of a negative consequence after a behavior weakens the behavior the introduction of a negative consequence after a behavior weakens the behavior Time out for hitting other children Time out for hitting other children  Negative Reinforcement the removal of a negative stimulus after a behavior strengthens the behavior the removal of a negative stimulus after a behavior strengthens the behavior Picking up a crying baby Picking up a crying baby