operant behavior & reinforcement

Operant behavior

(learned behavior) behavior that is mediated by its consequences

• VOLUNTARILY LEARNED

Operant conditioning

the process by which behavior is modified by its consequences

• If-then relationships 

• is “VOLUNTARY” behavior, is NOT automatic, it's due to what happened in the past 

Examples of If-Then Relations

• IF the lever is pressed, THEN food is presented

• IF the dog's tail is pulled, THEN the dog bites

Operant behavior

behavior that operates on the environment to produce consequences that have an effect on behavior

Operant class

group of responses that result in the same consequence

• May be of different topographies

  • example: all dogs sit down, it doesn’t matter HOW the dog sits, there are many different ways, but it’s the fact that they all sit down

Examples of operant behavior:

painting, talking, reading, writing, driving

Topography

the physical form of characteristics of the response

Function

the environmental changes produced by the operant response that control the response

Operant behavior varies in […] but is classified by its […]

topography AND function

Operant class

all the topographies that produce a common environmental consequence

• For example: “turning on a light” is an operant class that includes flipping a switch, lighting a candle, turning on a cell phone 

Discriminative stimulus (S^D)

any event/stimulus that precedes operant behavior and sets the occasion for behavior

• putting foot on gas peddle when green light is shown

ABC for S^{D (discriminative stimulus)}

A (antecedents discriminative stimuli) 

B (behavior)

C (consequences reinforcers)

discriminative stimuli DO NOT force a behavior, operant behavior is VOLUNTARY 

• Ex: Stop sign, it doesn't force you to stop, but it tells you to stop 

• Ex: Incoming calls, your phone is ringing, it sets the occasion for you to answer, but it doesn't make you answer the phone

• Ex: giving a high five, lifting your hand up to give someone a high five, sets the occasion for a high five, but it doesn't force either person to give you a high five

ABC for Contingency of Reinforcement

A (antecedent)

B (behavior)

C (consequences reinforcers)

Contingency of Reinforcement

the relationship between a behavior and the events that follow.

• “Sit” command. It doesn't automatically cause your dog to sit, it's not a reflex. If you haven't taught them the command to “sit” they won't know what your command means. The dog KNOWS how to sit on their own, but a command to teach the dog to sit on command has to be learned. 

• If you reinforce the behavior of your dog sitting with a treat, the treat will become a discriminative stimulus, because it will make them want to sit and learn to sit, in the process of the command will give them a treat. So they will sit under the conditions of the command being presented because they know they will be given a treat.

Four Basic Contingencies

• Positive reinforcement

• Negative reinforcement

• Positive punishment

• Negative punishment

Positive Reinforcement

The process by which a stimulus is PRESENTED after a response, and that response INCREASES in the future

Reinforcer (S^R)

• Consequence that follows a response

• Increases the probability of that response in the future

• The probability of the response increases because of the consequence 

EXAMPLES:

• A rat presses a lever – (reinforcer) food pellet delivered – INCREASES (positive) lever pressing 

• A child receives a good grade – parent praise – keeps getting good grades

Reinforcers are defined by the…

EFFECT they have ON BEHAVIOR, not by their physical characteristics.

• To be a POSITIVE REINFORCER, the contingent delivery of the stimulus or event MUST INCREASE or MAINTAIN the rate of response 

contingency

A reinforcement or punishment that occurs after a behavior has been expressed by an individual or group

Identifying a Reinforcing Stimuli

A stimulus/event is only a reinforcer if its presentation/removal increases or maintains the rate of the response that produced it

Determining if something is a reinforcer REQUIRES…

testing the effect of the stimulus/event

Demonstrating that something is a reinforcer is SEPARATE from…

explaining behavior

• Explanation requires identifying the operating contingencies of reinforcement

• You have to see the behavior change by an increase for it to count as a reinforcer
  

Factors Affecting the Efficacy of Reinforcement

1. Quality

   • Higher quality works better

   • How tasty are the pellets I give the rat?

2. Delay

   • A shorter delay works better 

   • Give the rat a pellet immediately after they press the lever

3. Quantity

   • More is better to a certain extent 

   • The rat presses the lever more when I give him 5 pellets than 1

4. Establishing Operations (EO) – Motivation

   • EOs may be necessary for some reinforcers

   • The rat will only press the lever if he is hungry 

5. Schedules of Reinforcement

   • How often do I give the rat a pellet for pressing the lever?

   • Different schedules of reinforcement produce different patterns of behavior

Establishing Operations (EO)

any environmental event or operant that:

• Momentarily INCREASES the reinforcing efficacy of a stimulus (makes it more valuable)

• And momentarily INCREASES the probability of the response necessary to obtain the reinforcement that has been altered

  • Make something more reinforcing, such as food deprivation

  • take away food —> hungry

Food deprivation

By depriving an organism of food, it makes food a stronger reinforcer and makes behavior involved in obtaining food more likely

• You want to make sure your animal is hungry to eat

Examples of EO’s

• When it is hot outside, you want to drink ice-cold water, go swimming

• When it's freezing outside, you want warm things, being by a fire, a warm bowl of soup

Abolishing Operations (opposite of establishing)

any environmental event or operant that:

• momentarily DECREASES the reinforcing efficacy of a stimulus

• And momentarily DECREASES the probability of the response necessary to obtain the reinforcement that has been altered

  • full —> food?

  • Abolishing is not a permanent change. Meaning if your full right now and dont see the appeal in eating food at that moment, you eventually will become hungry and want to eat food. 

Operant Conditioning from Thorndike

‘The control by behavioral consequences’ was described in 1911 by E. L. Thorndike

• Cats, dogs, and chicks were placed in situations where complex sequences of behavior would open a locked cage and gain access to food

• Thorndike measured learning as changes in the time taken to complete the puzzle task (latency)

Restatement of Thorndike’s law of effect:

The principle of reinforcement states that operants may be followed by the presentation of consequences that increase the rate of response.

• The idea that consequences could change the probability of behavior

Operant Rate

the number of operant responses that occur in some defined unit of time

• EX: 1,000 bar presses in 2 hours = 500 presses per hour

Probability of Response

the rate of the response is an indicator of its probability of occurring again in the future.

• A behavior that occurs at a high rate has a high probability of recurring while a low rate response has a low probability of recurring

Free-Operant Method

an experimental procedure where the organism is allowed to freely emit the operant response over an extended period

• Allows for the organism to respond as much or as little as they want. There are no restrictions.

• Allows us to focus on what consequences to implement to make that more or less likely to occur.

Operant Conditioning Procedures

• Deprivation

  • Calculation of average weight

  • Kept at 85% of free-feeding weight

• Magazine training

  • Rat placed in an operant chamber

  • Food delivery is preceded by the “click” of the feeder

  • Rats stay close to the feeder