operant conditioning. introduction through classical (pavlov) conditioning, an organism associates...
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Operant ConditioningOperant Conditioning
IntroductionIntroductionThrough classical (Pavlov) conditioning, an organism associates different stimuli that it does not control. Through operant conditioning, the organism associates its behaviors with consequences. Behaviors followed by reinforcements increase; those followed by punishers decrease. This simple but powerful principle has many applications and also several important qualifications.
Operant means…Operant means…
….Explain and train
Operant ConditioningOperant Conditioning•A type of learning in which
responses can be controlled by their consequences
i.e. rewards or
punishments
Reward vs. PunishmentReward vs. Punishment
Reward = more likely behavior will repeat
Punishment = less likely to repeat behaviorsWhich is better?
BehaviorBehavior
• 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 BoxPuzzle Box
Law of Effect
SkinnerSkinner• 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-Operant Conditioning
Edward L. ThorndikeEdward L. Thorndike• Law of Effect:
– Rewarded behavior is likely to recur– Puzzle Box
Operant Conditioning Chamber
Skinner BoxSkinner Box
Puzzle BoxPuzzle Box
Two important concepts used in Operant Two important concepts used in Operant ConditioningConditioning
• ReinforcerReinforcer– A stimulus or event that increasesincreases 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 again• Remember…Remember…
– It is often the learner that determines if something is a reinforcement or punishment
– This is called the Premack PrinciplePremack Principle– 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 behaviorAnything likely to increase a behavior
Positive Reinforcement
• Something desirable is addedadded to the environment and this encourages (reinforces)(reinforces) behavior– Behaviors are strengthened when they are followed
by the introduction of a stimulus
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Negative Reinforcement• Something undesirable is subtractedsubtracted from the
environment and this encourages (reinforces)(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 So…positive and negative do not mean good or bad. Instead, positive means bad. Instead, positive means addingadding a stimulus, a stimulus,
and negative means and negative means removingremoving a stimulus. a stimulus.
The SimpsonsThe Simpsons
Reinforcement Schedules
The pattern (schedule) in which reinforcement (reward
or punishment) is given.
These schedules influence learningThese schedules influence learning
Continuous Reinforcement
• Reinforcing the desired response every time it occurs.– Example – vending machine
Quick Quick AcquisitionAcquisition
Quick Quick ExtinctionExtinction
Partial Reinforcement• Reinforcing a response only part of the Reinforcing a response only part of the
time.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
– Two focus on timetime between reinforcement
(interval schedule)(interval schedule)– Two focus on numbernumber of responses between
reinforcement (ratio schedule)(ratio schedule)
Fixed-Interval Schedule
• Reinforcement of a behavior after a specified or fixed time (interval)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• Reinforcement of a behavior
at unpredictable (variable) timetime 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
• Reinforcement of a behavior only after a specified (fixed) numbernumber 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• Reinforcement of a behavior after an
unpredictable (variable) number number of responses.– Working on sales commission
• Sometimes called the gambler’s gambler’s scheduleschedule– 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 EffectOverjustification 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?”
Before we move on…• Operant Conditioning uses much of the same
terminology as classical conditioning…(acquisition, extinction, generalization, discrimination, etc…)
• For example, if I want a child to increase his bathing behavior, I can give him an extra 30 minutes of TV time after he bathes.
• The reinforcer is extra TV time and acquisition occurs when he links together the idea that bathing gives him more Cartoon Network.
• Extinction would occur if I stop giving him TV time for bathing and he stops seeing the association.
Types of Reinforcers
Types of ReinforcersTypes 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
Intrinsic vs. Extrinsic Motivation
PunishmentPunishment• 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 Does punishment work?work?
Yes, Yes, but…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 Difference between Negative Reinforcement and PunishmentReinforcement and Punishment
Punishment Punishment the introduction of a negative the introduction of a negative
consequence after a behavior weakens consequence after a behavior weakens the behaviorthe behavior
Time out for hitting other childrenTime out for hitting other children
Negative ReinforcementNegative Reinforcement the removal of a negative stimulus after a the removal of a negative stimulus after a
behavior strengthens the behaviorbehavior strengthens the behavior Picking up a crying babyPicking up a crying baby
Observational Observational LearningLearning
Learning by ObservationLearning by Observation Learning occurs not Learning occurs not
only through only through conditioning but conditioning but also from our also from our observation of observation of others. others.
““We are, in truth, We are, in truth, more than half what more than half what we are by imitation”we are by imitation”
Lord Lord ChesterfieldChesterfield
Observational Learning: Observational Learning: DefinitionDefinition
Observe and imitate Observe and imitate othersothers
ModelingModeling- Process of - Process of observing and observing and imitating a specific imitating a specific behaviorbehavior
We learn all kinds of We learn all kinds of social behaviors by social behaviors by observing and observing and imitating othersimitating others
Mirror NeuronsMirror Neurons
Mirror neurons provide a neural basis for Mirror neurons provide a neural basis for observational learningobservational learning
Example: when a baby imitates a face an Example: when a baby imitates a face an adult is making, mirror neurons are firingadult is making, mirror neurons are firing
Bandura’s ExperimentBandura’s Experiment
Albert BanduraAlbert Bandura Pioneer of research Pioneer of research
in observational in observational learninglearning
BoBo Doll BoBo Doll ExperimentExperiment Reinforcement and Reinforcement and
punishment leads punishment leads to imitating a to imitating a behaviorbehavior
Social Influence on Social Influence on Observational LearningObservational Learning
Columbine High School- Columbine High School- “copycat threats”“copycat threats”
Prosocial- models can have Prosocial- models can have positive effectspositive effects
Gandhi and Martin Luther King Gandhi and Martin Luther King Jr.Jr.
Television:Television: More hours children spend More hours children spend
watching violent TV or playing watching violent TV or playing violet video games, more at risk violet video games, more at risk for aggression and crime as for aggression and crime as teens and adultsteens and adults
Homicides doubled between Homicides doubled between 1957 and 1974, coinciding with 1957 and 1974, coinciding with the introduction of televisionthe introduction of television
Aversive ConditioningAversive Conditioning In aversive conditioning, client is exposed to an In aversive conditioning, client is exposed to an
unpleasant stimulus while engaging in the unpleasant stimulus while engaging in the targeted behaviortargeted behavior
Goal- create an aversion to it. Goal- create an aversion to it. In adults, aversive conditioning is often used to In adults, aversive conditioning is often used to
combat addictions such as smoking or alcoholism. combat addictions such as smoking or alcoholism. Examples-Nausea-producing drug while the client Examples-Nausea-producing drug while the client
is smoking or drinking so that unpleasant is smoking or drinking so that unpleasant associations are paired with the addictive associations are paired with the addictive behavior. behavior.
Also used to treat nail biting, sex addiction, and Also used to treat nail biting, sex addiction, and other strong habits or addictions.other strong habits or addictions.
Observational Learning influenced debates on the effect of television violence and
parental role models
Studies have shown the amount Studies have shown the amount of violent TV watched by children of violent TV watched by children
in elementary school is correlated with in elementary school is correlated with their aggressiveness as teenagers their aggressiveness as teenagers
and with their criminal behavior as adultsand with their criminal behavior as adults
Antisocial models vs. prosocial models