DefinitionWhen a Stimulus is removed (terminated,

reduced, or postponed) contingent on a response, it results in an increase in the future probability of that response

Positive vs. Negative ReinforcementHow they are similar:

Both increase responding

How they are different:Positive: A stimulus is provided following a response and behavior increasesNegative: A stimulus is removed following a response and the behavior increases

Positive vs. Negative ReinforcementEO

Absence of food for 2

hours

SD

Teacher says “Snack time”

and apples on table

Response

“Apple, please”

SR+

Apple presented

Saying “Apple, please” when it is snack time and apples are present more likely in the future

Positive reinforcement:

EO

Math worksheet

with 20 problems on

student’s desk

SD

Teacher says “Complete 5 problems,

then you don’t have to do the

rest”

Response

Completes 5 problems

SR-

Remaining problems on worksheet removed

Completing problems when math worksheet and teacher instructions present more likely in the future

Negative reinforcement:

Can be Difficult to DetermineTurning up the heat

Adds heat Removes cold

Free time contingent on work completion Adds preferred activities Removes work

Michael (1975)Suggests the distinction is not importantInstead, define key stimulus features

Before the stimulus changeAfter the stimulus change

May provide a more complete, functional understanding of the relationship between the behavior and environment

Negative Reinforcement vs. Pos. Punishment

Not good vs. badPositive refers to presentation of the stimulus

and Negative refers to the termination of the stimulus

Both can involve “aversive” eventsNegative reinforcement, the aversive event is

present prior to the target behavior, once removed, behavior increases

Punishment, the aversive event is presented contingent on the target behavior, behavior decreases

Negative Reinforcement vs. Punishment

SD

Teacher says “Complete 5 problems,

then you don’t have to do the

rest”

Response

Destroys worksheet

SP+

Teacher requires

student to complete all 20 problems

Destroying worksheet less likely in the future

Punishment:

EO

Math worksheet

with 20 problems on

student’s desk

SD

Teacher says “Complete 5 problems,

then you don’t have to do the

rest”

Response

Completes 5 problems

SR-

Remaining problems on worksheet removed

Completing problems more likely in the future

Types of Negative ReinforcementEscape Avoidance

Escape ContingencyIncludes 4 terms

Establishing operation Aversive event from which escape is reinforcing

A discrimintive stimulus (SD)A responseThe reinforcer (termination of the EO)

Escape and Avoidance ContingenciesEscape Contingency

EO

Rain falling on your

head as you walk down sidewalk

SD

Friend says “Do you have an

umbrella?”

Response

Put up umbrella

SR-

Escape rain falling on your head

Putting up umbrella more likely in the future when it’s raining and friend asks for umbrella

Escape and Avoidance ContingenciesAvoidance Contingency

EO

Rain outside;

you are still inside--nice

and dry

SD

Friend says “Do you have an

umbrella?”

Response

Put up umbrella (prior to going

outside)

SR-

Avoid rain falling on your head Putting up

umbrella more likely in the future when it’s raining and friend asks for umbrella

Examples Aspirin for Head AcheDrug Abuse

Negative Reinforcement CharacteristicsAny response can be strengthened by

negative reinforcementA variety of stimuli can serve as negative

reinforcersUnconditionedConditioned

Negative reinforcement can beSocially mediated (delivered by another person)Automatic (is produced directly by the person’s

response)

Factors Influencing EffectivenessImmediacy: Is delivered immediately

following the target behaviorMagnitude: The larger the reinforcement the

greater the responseSchedule: It is delivered consistentlyAvailability: Reinforcement is unavailable for

competing (non-target) responses

Ethical ConsiderationsLike positive reinforcement, ethical issues

arise from the severity of the EO that may need to be in place to motivate the occurrence of the behaviorThe presence of particularly aversive

antecedent stimuli may be problematicThese stimuli may generate undesirable

competing behaviors

ConclusionsNegative Reinforcement can be used

effectively in various situationsNeed to identify the reinforcers the same way

as with Positive reinforcement procedures

Often need to identify in relation to determine what is controlling a behavior.