Operant Conditioning

Comparing Classical and Operant Conditioning

• Both classical and operant conditioning use acquisition, extinction, spontaneous recovery, generalization, and discrimination.

• Classical conditioning uses reflexive behavior - behavior that occurs as an automatic response to some stimulus.– Ask: Is the behavior something the animal can control? NO. Does

the animal have a choice in how to behave? NO. - Classical conditioning.

• Operant conditioning uses operant or voluntary behavior – voluntary behavior that is shaped by consequences.– Ask: Is the behavior something the animal can control? YES. Does

the animal have a choice in how to behave? YES. - Operant Conditioning.

What is Operant Conditioning?

Operant Conditioning

• A type of learning in which the frequency of a behavior depends on the consequence that follows that behavior

• The frequency will increase if the consequence is reinforcing to the subject.

• The frequency will decrease if the consequence is not reinforcing or punishing to the subject.

The Law of Effect

Edward L. Thorndike ( 1874–1949)

Thorndike’s Puzzle Box

Thorndike’s Puzzle Box

• “Thorndike’s Puzzle Box” Video #8 from Worth’s Digital Media Archive for Psychology.

B. F. Skinner (1904–1990)

B.F. Skinner (1904-1990)

• Believed that internal factors like thoughts, emotions, and beliefs could not be used to explain behavior. Instead said that new behaviors were actively chosen by the organism

• Developed the fundamental principles and techniques of operant conditioning and devised ways to apply them in the real world

• Designed the Skinner Box, or operant chamber

The Skinner Box

Reinforcement/Punishment

• Reinforcement - Any consequence that increases the likelihood of the behavior it follows– Reinforcement is ALWAYS GOOD!!!

• Punishment - Any consequence that decreases the likelihood of the behavior it follows

• The subject determines if a consequence is reinforcing or punishing

Types of Reinforcement

Principles of Reinforcement  

  Reinforcing/Desirable Stimulus

Aversive/UnDesirableStimulus

Stimulus is presented or added to animal’s environment…

 

Positive (+) Reinforcement

Add something you DO LIKE.Behavior Increases

  

Chocolate

 

Positive (+) Punishment

Add something you DO NOT LIKE.

Behavior Decreases

More chores

Stimulus is removed or taken away from animal’s environment…

 

Negative (-) Punishment

TAKES AWAY something you DO LIKE.

Behavior Decreases 

No TV

 

Negative (-) Reinforcement

TAKES AWAY something you DO NOT LIKE.

Behavior Increases 

 Fewer chores

Positive Reinforcement

• Strengthens a response by presenting a desirable stimulus after a response

• Anything that increases the likelihood of a behavior by following it with a desirable event or state

• The subject receives something they want (it is added or given)

• Will strengthen the behavior

Positive Reinforcement

Negative Reinforcement“Reward through ESCAPE”

• Strengthens a response by reducing or removing an aversive (disliked) stimulus

• Anything that increases the likelihood of a behavior by following it with the removal of an undesirable event or state

• Something the subject doesn’t like is removed (subtracted)

• Will strengthen the behavior• Still a REWARD!!!!! It’s desirable.

Negative Reinforcement

Positive/Negative Reinforcement

BOTH ARE GOOD THINGS!!!

Billy Throws a Tantrum• Billy throws a tantrum, his parents give in for the

sake of peace and quiet. • How is this an example of positive reinforcement?• The child’s tantrum is reinforced when the parents

give in (pos. reinforcement). • How is this ALSO an example of negative

reinforcement?• The parents’ behavior will be reinforced when

Billy stops screaming (neg. reinforcement). They may continue to give in.

Primary Versus Secondary

Reinforcement

Primary Reinforcement

• Something that is naturally reinforcing

• Examples: food, warmth, water, etc.

• The item is reinforcing in and of itself

Secondary Reinforcement

• Something that a person has learned to value or finds rewarding because it is paired or associated with a primary reinforcer

• Money is a good example. • So are grades and signs of respect &

approval.

Immediate Versus Delayed

Reinforcement

Immediate Reinforcers

• Immediate reinforcers – behaviors that immediately precedes the reinforcer becomes more likely to occur – (This is true when training animals.

Can’t wait for a long time before reinforcing or the animal. It won’t know what behavior you are reinforcing)

Delayed Reinforcers

• Also called Delayed Gratification – forgoing a small immediate reinforcement for a greater reinforcement later.

• Humans do this with paychecks, grades.

• When do we not do this? – Stay up late to watch TV when next day we’re

tired.– Smoke for satisfaction now when later it will

kill us.

Punishment:The Process of

Punishment

Types of Punishment

• An undesirable consequence following a behavior

• The behavior ends a desirable state.

• Its effect is opposite of reinforcement – it decreases the frequency of behavior

Positive Punishment(Punishment by Application)

• Something is added to the environment you do NOT like.

• A verbal reprimand, extra chores, or something painful like a spanking

Negative Punishment(Punishment by Removal)

• Something is taken away that you DO LIKE.

• Lose a privilege, no TV, no dessert, grounded (lose freedom).

• “Time out” for toddlers takes them away from their activity.

The Good Effects of Punishment

• Punishment can effectively control certain behaviors if…– It comes immediately after the undesired

behavior – It is consistent and not occasional

• Especially useful if teaching a child not to do a dangerous behavior

• Most still suggest reinforcing an incompatible behavior rather than using punishment

Bad Effects of Punishment

• Does not teach or promote alternative, acceptable behavior.

• Only tells what NOT to do while reinforcement tells what to do.

• Doesn’t prevent the undesirable behavior when away from the punisher in a “safe setting”

• Can lead to fear of the punisher, anxiety, and lower self-esteem

• Children who are punished physically may learn to use aggression as a means to solve problems.

How is Punishment & Reinforcement being used to treat severely autistic and/or violent children?

See CNN video clip from Anderson Cooper 360.

Do you think they should be using these conditioning methods on these kids?

Extinction

• In operant conditioning, the loss of a conditioned behavior when consequences no longer follow it.

• The subject no longer responds since the reinforcement or punishment has stopped.

Some Reinforcement Procedures:

Shaping

Shaping Principles• Shaping - procedure in which rewards, such as food,

gradually guide an animal’s behavior toward a desired behavior.

• Successive approximations - shaping method in which you reward responses that are ever closer to the final desired behavior and ignore all other responses.

• Shaping nonverbal animals can show what they perceive. Train an animal to discriminate between classes of events or objects. – After being trained to discriminate between flowers, people, cars,

and chairs, a pigeon can usually identify in which of these categories a new pictured object belongs

Skinner attached some horizontal stripes to the wall which he then used to gauge the dog's responses of lifting its head higher and higher. Then, he simply set about shaping a jumping response by flashing the strobe (and simultaneously taking a picture), followed by giving a meat treat, each time the dog satisfied the criterion for reinforcement. The result of this process is shown below, as it was in LOOK magazine, in terms of the pictures taken at different points in the shaping process. Within 20 minutes, Skinner had Agnes "running up the wall"

For the second shaping demonstration, Skinner trained Agnes to press the pedal and pop the top on the wastebasket. Again, the photographer's flash served as the conditioned reinforcer, and each step in the process was photographed. The results are shown below.

Schedules of Reinforcement

Continuous reinforcement

• A schedule of reinforcement in which a reward follows every correct response

• Learning occurs rapidly

• But the behavior will extinguish quickly once the reinforcement stops.– Once that reliable candy machine eats your money

twice in a row, you stop putting money into it.

Partial Reinforcement

• A schedule of reinforcement in which a reward follows only some correct responses

• Learning of behavior will take longer

• But will be more resistant to extinction

• Includes the following types:

– Fixed-interval and variable interval

– Fixed-ratio and variable-ratio

Fixed-Ratio Schedule

• A partial reinforcement schedule that rewards a response only after some defined number of correct responses

• The faster the subject responds, the more reinforcements they will receive.

• i.e. piece work: You get $5 for every 10 widgets you make.

Variable-Ratio Schedule

• A partial reinforcement schedule that rewards an unpredictable average number of correct responses

• High rates of responding with little pause in order to increase chances of getting reinforcement

• This schedule is very resistant to extinction.• Sometimes called the “gambler’s schedule”;

similar to a slot machine or fishing

Fixed-Interval Schedule

• A partial reinforcement schedule that rewards only the first correct response after some defined period of time

• Produces gradual responses at first and increases as you get closer to the time of reinforcement

• Example: a known weekly quiz in a class, checking cookies after the 10 minute baking period.

Variable-Interval Schedule

• A partial reinforcement that rewards the first correct response after an unpredictable amount of time

• Produces slow and steady responses

• Example: “pop” quiz in a class

Schedules of Reinforcement

Ask Yourself…• Is the example dealing with the animal doing a

behavior? - Ratio– Does the number of times the animal does the behavior

vary for reinforcement? Variable– Does the animal do the behavior a set number of times

for reinforcement? Fixed

• Is the example dealing with the amount of time that elapses from the behavior till it gets reinforcement? - Interval– Does the amount time between the behavior and

reinforcement vary? Variable– Is the amount of time between the behavior and

reinforcement stay the same? Fixed

Class Activity

• 4 Volunteers are needed to demonstrate schedules of reinforcement

• No punishment will be used.

• You will remain dry for the entire activity.

Variable Ratio• 1:1/ 7:1 / 4:1 / 12:1 / 8:1 / 19:1 / 3:1 / 2:1 / 2:1 / 5:1 / 16:1 /

11:1 / 3:1 / 8:1 / 4:1Fixed Ratio• 7:1 / 7:1 / 7:1 / 7:1 / 7:1,…. 15 timesFixed Interval• 10 sec:1 / 10 sec:1 / 10 sec:1 / ,… 15 timesVariable Interval• 6 sec:1 / 8 sec:1 / 10 sec:1 / 3 sec:1 / 7 sec:1 / 14 sec:1 / 15

sec:1 / 8 sec:1 / 5 sec:1 / 12 sec:1 / 6 sec:1 / 9 sec:1 / 13 sec:1/15 sec:1 / 8 sec:1

New Understandings of Operant

Conditioning: The Role of Cognition

Skinner & Thorndike

• Believed that cognitions (thoughts), perceptions, and expectations have no place in psychology.

• This is because they cannot be studied through observation and therefore were seen as not being objective.

Latent Learning

• Learning that takes place in absence of an apparent reward

• Idea developed by E.C. Tolman

E.C. Tolman’s Rat Maze Experiment• Three groups of rats were trained to run a maze. • The control group, Group 1, was fed upon reaching the goal. • The first experimental group, Group 2, was not rewarded for

the first six days of training, but found food in the goal on day seven and everyday thereafter.

• The second experimental group, Group 3, was not rewarded for the first two days, but found food in the goal on day three and everyday thereafter.

Tolman’s Rat Maze Experiment (continued)

• Both of the experimental groups demonstrated fewer errors when running the maze the day after the transition from no reward to reward conditions. The marked performance continued throughout the rest of the experiment.

• This suggested that the rats had learned during the initial trials of no reward and were able to use a "cognitive map" of the maze when the rewards were introduced.

• The initial learning that occurred during the no reward trials was what Tolman referred to as latent learning.

• He argued that humans engage in this type of learning everyday as we drive or walk the same route daily and learn the locations of various buildings and objects. Only when we need to find a building or object does learning become obvious.

Cognitive Map

• A mental representation of a place

• Experiments showed rats could learn a maze without any reinforcements

Other evidence that we do think!

• Animals on a fixed-interval reinforcement schedule though respond more frequently as the time approaches for their reinforcer as if they expect that the response will produce the reward

Overjustification Effect• The effect of promising a reward for doing what

someone already likes to do• The reward may lessen and replace the person’s

original, natural motivation, so that the behavior stops if the reward is eliminated– The person may now see the reward, rather than intrinsic interest, as

the motivation for performing the task. – “If I have to be bribed into doing this, then it’s not worth doing for its

own sake.”

• Rewards do help increase interest when used to indicate a job well done

Learned Helplessness• Dogs in electrified cage at first not able to escape

the impending shock.

• Later, all they had to do was cross to the other side but they didn’t even try.

•The dogs had learned they were “helpless” to avoid the shock and just sat there and took it without trying to escape.

Learned Helplessness

• Exposure to inescapable and uncontrollable aversive events produces passive behavior. If an animal believes or expects it cannot escape undesirable circumstances, it will give up trying to escaping those circumstances.

• To overcome this, one must establish a sense of control over one’s environment and see some success.

Biological Predispositions• Animal training issues –

easier to train behaviors that are closer to natural behaviors using a natural reinforcer (food).

•Instinctive drift—naturally occurring behaviors that interfere with operant responses.

•What happens when a trained tiger shows instinctive drift?

Classical Conditioning vs. Operant Conditioning