experimental psychology -operant conditioning

7/28/2019 Experimental Psychology -Operant Conditioning

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OPERANT CONDITIONING (OR INSTRUMENTAL CONDITIONING)

Operant conditioning is a type of learning in which an individual's behavior is modified by its

consequences in an environment. Through operant conditioning, an association is made

between a behavior and a consequence for that behavior. The behavior may change in form,frequency, or strength. Operant conditioning is a term that was coined by B.F Skinner in 1937.

The word operant can be described as, "any active behavior that operates upon the

environment to generate consequences".

Operant conditioning deals with the modification of "voluntary behavior" or operant behavior.

Operant behavior operates on the environment and is maintained by its consequences.



POSITIVE AND NEGATIVE – REINFORCEMENT AND PUNISHMENT

POSITIVE REINFORCEMENT

Positive reinforcement, and is defined as a stimulus that strengthens an operant response when

it is presented after the response.

Positive reinforcement occurs when a behavior (response) is followed by a stimulus that is

appetitive or rewarding, increasing the frequency of that behavior. In the Skinner box

experiment, a stimulus such as food or a sugar solution can be delivered when the rat engages

in a target behavior, such as pressing a lever.

o Giving a child a compliment or candy for a job well done.

o Getting paid for a completed task.

o Watching your favorite TV show after doing all your homework.

o Dolphin gets a fish for doing a trick.

o Dog gets a treat for sitting, laying, rolling over.

o Get a candy bar for putting money in the machine.

The word “positive” in positive reinforcement refers to the fact that the stimulus is presented

after the operant response rather than removed after the operant response. It does not mean

that the stimulus necessarily was something that the person found to be pleasant.

An important thing to note is that positive reinforcement is not always a good thing. For

example, when a child misbehaves in a store, some parents might give them extra

attention or even buy the child a toy. Child ren quickly learn that by acting out, they can

gain attention from the parent or even acquire objects that they want. Essentially,

parents are actually reinforcing the misbehavior. In this case, the better solution wouldbe to use positive reinforcement when the child is actually displaying good behavior.

Positive reinforcement is most effective when it occurs immediately after the behavior. The

shorter the amount of time between a behavior and the presentation of positive

reinforcement, the stronger the connection will be. If a long period of time elapses between the

behavior and the reinforcement, the weaker the connection will be.



NEGATIVE REINFORCEMENT

Negative reinforcement is a term described by B. F. Skinner in his theory of operant

conditioning. In negative reinforcement, a response or behavior is strengthened by stopping,

removing or avoiding a negative outcome or aversive stimulus.

Aversive stimuli tend to involve some type of discomfort, either physical or psychological.Behaviors are negatively reinforced when they allow you to escape from aversive stimuli that

are already present or allow you to completely avoid the aversive stimuli before they happen.

1. Loud buzz in some cars when ignition key is turned on; driver must put on safety belt in

order to eliminate irritating buzz the buzz is a negative reinforcer for putting on the seat-

belt.

2. Feigning a stomach ache in order to avoiding school school as negative reinforcer for

feigning stomach aches.

3. Rushing home in the winter to get out of the cold. Fanning one-self to escape from the heat

Cold weather as negative reinforcer for walking home (the colder the faster you walk..),and heat is negative reinforcer for fanning.

4. Cleaning the house to get rid of disgusting mess or cleaning the house to get rid of your

mother's nagging Nagging/Mess as negative reinforcer to cleaning.

5. Studying for an exam to avoid getting a poor grade Low grade as a negative reinforcer for

studying (but.. a high grade is a positive reinforcer for studying at the same time)

6. Taking aspirin to relieve headache Good example: headache as negative reinforcer to

taking medication.

7. Removing a stone that has lodged inside the shoe while walking Pain as negative

reinforcer to stopping to take off your shoe.

8. Prisoners try to break out of jail to escape the aversiveness of being locked up.

9. Leaving a movie theater if the movie is bad.

10. Running from the building when the fire alarm sounds Fire alarm as negative reinforcer

for leaving building.

11. Smoking in order to reduce a negative emotional state Negative emotional state as

negative reinforcer to smoking.

12. Turning down the volume of a very loud radio.

13. Changes in sexual behavior (e.g., wearing condoms) to avoid AIDS.



Other examples include:

o Scratching an insect bite that itches (reinforces scratching behavior by removing itch)

o Rubbing itchy eyes (reinforces rubbing behavior by removing itch)

o Daydreaming or doodling in boring class (reinforces daydreaming behavior by removing

boredom)o Studying when you worry about a test (reinforces study behavior by reducing worry)

OR

o Watching TV when you worry about a test (procrastination or giving up on it) (reinforces

TV watching behavior by removing worry)

o Taking a pain reliever to reduce pain (reinforces pill-taking behavior by removing pain)

o Taking a drug to decrease the anxiety.

Anxiety reduction is an important negative reinforcer of addictive behaviors. The taking

of an addictive drug may be followed not only by pleasure (a positive reinforcement), it

also may be followed by decreases in negative emotional states, such as anxiety.

Negative reinforcement is most effective when reinforcers are presented immediately following

a behavior. When a long period of time elapses between the behavior and the reinforcer, the

response is likely to be weaker.

PSITIVE PUNISHMENT

Positive punishment is defined as a stimulus that weakens an operant response when it is

presented after the response.

o Yelling “No!” at a dog jumping up on a person (adds scold to reduce behavior)

o Spanking a child

o Swatting a dog with a newspaper for peeing on the carpet.

o A speeding ticket for speeding.o Squirting a cat for eating the plants.

o Burning your hand when you touch a hot stove.

o Getting nauseous after eating rotten food.

NEGATIVE PUNISHMENT



Negative punishment is defined as a stimulus that weakens an operant response when it is

removed after the response.

o Child has a toy taken away for fighting with his sister.

o Teen is grounded for misbehavior.

o Dolphin trainer walks away with fish bucket when the dolphin gets aggressive.

o One person in a relationship stops talking to the other in response to a behavior.

EFFECTIVENESS OF PUNISHMENT

Negative punishment is most effective if:

It immediately follows a response

It is applied consistently

It is strong

Punishment also has some notable drawbacks. First, any behavior changes that result from

punishment are often temporary. "Punished behavior is likely to reappear after the punitive

consequences are withdrawn,”. Another thing to consider about punishment is that it can have

unintended and undesirable consequences like aggression or antisocial behaviors and also

doesn’t indicate the right behavior. It is good for short-term behavior modifications in case of

emergency like self-destructive behavior of a autism child, or dangerous behaviors that should

be stopped immediately.

SCHEDULES OF REINFORCEMENT

Continuous reinforcement (CRF) – Is a schedule of reinforcement in which every

occurrence of the instrumental response (desired response) is followed by the reinforcer.

Examples:

o Each time a rat presses a bar it gets a pellet of food.

o Each time a dog defecates outside its owner gives it a treat, each time a person puts $1 in a

candy machine and pressed the buttons they receive a candy bar.



o Using a token to ride the subway.

o Putting a dime in the parking meter.

o Putting coins in a vending machine to get candy or soda.

Fixed ratio (FR) – schedules deliver reinforcement after a specific amount of response.

Examples:

o Taking a multi-item test. As soon as you finish the items, you can leave.

o Garment worker gets paid per each 100 dresses sewn.

o Frequent flyer program: getting a free flight after accumulating x number of flight miles.

o Factory worker paid on piece work, paying on commission, or getting a bonus for every x

number of items sold.

o Mailman must visit the same number of mail boxes each day in order to go home.

o Going up a staircase, you must go up the same number of stairs to get to the landing.

o Teenager is paid by the job (e.g., amount of work completed).o Doing 20 sit ups to keep fit.

Variable ratio schedule (VR) – a reinforcement schedule in which the number of

responses necessary to produce reinforcement varies from trial to trial.

Examples:

o Playing a slot machine – the machine is programmed to pay off after a certain number of

responses have been made, but that number keeps changing. This type of schedules

creates a steady rate of responding, because players know if they play long enough, theywill win. It could be the next pull.

o Hunting – you probably won’t hit something every time you fire, but it’s not the amount of

time that passes, but the number of times you shoot at a prey that will determine how

much game you will catch.

o Sales commission – you have to talk to many customers before you make a sale, and you

never know whether the next one will buy.

o Phone sales – same as commission.

o Buying lottery tickets.

o Playing bingo.

o Signaling while hitchhiking.

o Custodians cleaning the school – sometimes rooms are already fairly clean; sometimes they

have to clean after a lab or “party.”

o Using drugs to escape withdrawal symptoms.

o Fly fishing: casting and reeling back several times before catching a fish.

o Sports games: e.g., variable number of strokes to finish a hole of golf; variable number of

swings to hit the baseball; variable number of throws to get the basketball in the hoop;

variable number of throws to get a strike in bowling.



Fixed interval (FI) – reinforced after a specific amount of time.

Examples:

o Test preparation when you know the date and time of the test ahead of time. As the time

goes by and you haven’t studied, you have to make up for it all by the predetermined time – and this means cramming.

o Picking up a salary check – every week or once every two weeks.

o Looking at your watch during a lecture.

o Checking cookies in the oven when you know how long it takes to bake.

o Bill-passing behavior on the part of congress. This behavior has been shown to increase as

the recess period approaches.

o Going to the cafeteria to see if the next meal is already available.

o Picking up the paper in the morning after it has been delivered at the same time every day.

Variable Interval (VI) - a reinforcement schedule in which the amount of time necessary

to produce reinforcement varies from trial to trial.

Examples:

o Pop quizzes – theoretically causes a steady rate of studying because you never know when

they’ll occur, so you have to be prepared all the time.

o Dialing a friend and getting a busy signal – this means that you’ll have to keep dialing every

few minutes because you don’t know when the line will be available. Reinforcementdoesn’t depend on the number of times you dial, but the unknown amount of time that

passes.

o Watching a football game, waiting for a touchdown. It could happen anytime – if you leave

the room, you may miss it, so you have to keep watching continuously.

o Speed traps on the highway.

o Mail-checking behavior assuming that mailperson comes at irregular intervals.

o Waiting for a taxi cab.

o Random drug testing; worker refrains from taking drugs.

experimental psychology -operant conditioning

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