Positive Reinforcement

SkinnerSystematically Demonstrated Several Things.

1. If something occurs after the response (consequent stimulus) and the behavior increases,

The procedure is called reinforcement, and the thing that caused the increase is called a reinforcer.

Points to Note:A stimulus is presented Reinforcement is contingent on a response (also Pun)Increases the future probability of the response

The future increase in the response is a critical feature in defining reinforcement

Reinforcement does not Increase Behavior Under All Conditions

*Must have a temporal relation between*Antecedent Stimuli or VariablesResponsesConsequencesAntecedent variables become discriminitive stimuli (SDs)A response in the presence of this stimulus will be reinforced.

Thus, the response is more likely to occur in the future in the presence of these stimuli

The Discriminated OperantAKA The Three-term ContingencySDTap on faucet is marked with a blue dot or letter CResponseTurn tap on with a blue dot or CSR+Cold water is presentedTurning tap marked with blue dot or C occurs more often in the future

Reinforcement Depends on Motivation

The SD will only signal the response if the individual is motivated to engage in the response

Motivating Operations (MOs)Can alter the reinforcing effectiveness of stimuliThus changes the frequency of respondingChanges the frequency of responses reinforced by those stimuliTwo typesEstablishingAbolishing

Two TypesEstablishing Operations (EO)Increases the effectiveness of a stimulus as a reinforcerUsually involves decreased access to the stimulus (deprivation)

Abolishing Operation (AO)Decreases the effectiveness of a stimulus as a reinforcerUsually involves having increased access to the stimulus (satiation)

The Four-term ContingencyThe consideration of MOs are important in relation to the three-term contingency

May Not OccurWater may be awfulMay act as a stimulator to find other water (Culligan man)

More Points to note

Person does not have to be aware that a response is being reinforced for it to increaseThe effect is automatic.

All behaviors are susceptible to reinforcement Key: Must have a temporal relation between the response and the consequence.

Variables Influencing Positive ReinforcementScheduleImmediacy / Delay MagnitudeOthers

ScheduleFixed vs. Variable SchedulesFR-1 Best responding, Fastest ExtinctionVRHighest rates of responding, Greatest resistance to extinction

Immediacy of ReinforcementIt is critical that the consequence is delivered immediately following the target responseLonger the delay, poorer the respondingSmall immediate reinforcers have greater power than delayed larger reinforcers Self-Management issue

Problems with delay of reinforcersOther behaviors occur during the delay

The behavior temporarily closest to the presentation of the reinforcer will be strengthenedMay not be the one you desire to change

Delayed ReinforcementDoes not necessarily reinforce the target behavior; rather influences itInstructional Control / Rule Following behaviorRule: Is a verbal description of a behavioral contingencyCan allow delayed consequences to influence behavior

How to Suspect Rule-governed BehaviorNo immediate consequence is apparentResponse-consequence delay > 30 are longer than secondsLarge increase in frequency of the behavior occurs following one instance of reinforcementNo consequence for the behavior exists (including no automatic reinforcement), but rule does

Superstitious BehaviorOccurs when reinforcement accidentally follows a behavior that did not produce the reinforcementSports players

A teacher consoling a child who hurt themself may reinforce crying and / or hurting themself

Automatic ReinforcementReinforcement occurs independent of another person delivering itThe response, itself, produces the reinforcementExamplesWiggling your leg during a boring lecture to stimulate yourself and stay awake

Note: This does not mean the behaviors are automatic (i.e., reflexive); rather that the consequences are delivered automatically

CLASSIFYING REINFORCERS

Reinforcers by OriginPrimary or Unlearned Reinforcers Function as reinforcers due to heredity / evolutionDo not require any learning history to become reinforcersFood, water, oxygen, warmth, sexual stimulation, human touch

Conditioned or Secondary ReinforcersAre learned Get power from association with primary reinforcersNeutral stimuli that begin to function as reinforcers as a result of being paired with other reinforcers (either conditioned or unconditioned)Can occur through Classical ConditioningCan also condition reinforcers through verbal analog conditioningExamples: Yellow paper, stickers, tokensSticker becomes the reinforcer

Generalized ReinforcersAre conditioned reinforcers that have been paired with many conditioned and unconditioned reinforcers

Do not depend on a specific EO to be effective

Examples: money, points, tokens, others

Reinforcers by Formal PropertiesEdible reinforcers (food)Sensory reinforcers (massage, tickles)Tangible reinforcers (trinkets, toys)Activity reinforcers (playing a game, recess)Social reinforcers (physical proximity, social interaction)May Differ Across Societies or People

Identifying Potential Reinforcers Is important to identify reinforcers empiricallyStaff, parents, teachers, and even children themselves who report what they believe to be reinforcers are often wrongTwo strategies to use in tandemStimulus Preference AssessmentsReinforcer Assessments

Points to note:Preferences change over timeEvaluate frequentlyPreference assessments do not identify the reinforcing effects Just because people prefer paper towels to hot-air hand dryers in public restrooms doesnt mean theyll work to earn paper towels!

Stimulus Preference AssessmentsIdentifyStimuli a person prefersRelevant preference valuesConditions under which these preferences hold trueThree CategoriesAsking about stimulus preferencesObserving the target person under free-operant conditionsPresenting various stimuli in a series of trial-based observation

Ask the Target Person

Use Open-ended questionsWhat would you like to work for?Asking about specific itemsHow would you like to work for stickers?Choice formatWould you rather work for things to eat or things to do?Rank order formatPut these items/activities in order from which youd like to work for most to which youd like to work for least.Offering Pre-task ChoicesWhen you are finished working, you can play with Battleship, checkers, or the computerAsking Significant OthersAsk caregivers to identify preferred stimuli

Points to NoteIs relatively uncomplicated ProblemsVerbal reports may not correspond to actual behavior

Free-Operant ObservationObserving and recording what activities the target person engages in when he/she has unrestricted choice of activitiesNo response requirementsAll stimuli available within sight and reachItems are never removedCan be contrived or naturalisticTwo types

Contrived Free-Operant ObservationJust prior to observation, provide learner with noncontingent exposure to each item (for sampling purposes)Place all items in view and within reachObserve for a set period of time and record the duration of time target person engages with each stimulus item

Naturalistic Free-Operant ObservationConducted in everyday environments as unobtrusively as possible (e.g., during recess)Observe for a set period of time and record the duration of time target person engages with each stimulus item/activity

Advantages of Free-Operant AssessmentsLess time consuming than trial-based methodsLess likely to produce problem behavior because preferred stimuli are never removed.

Trial-Based MethodsGeneral ProcedurePresent selected stimuli to children in a series of trialsMeasure approach (e.g., eye gaze, hand reach), contact (e.g., touch/hold), and/or engagement (e.g., interacting with stimulus)Can categorize as high, medium, and low preference

Many variations for procedure

Single Stimulus PresentationPresent stimuli, one at a time, in random order and record target persons reaction to itWell suited for individuals who have difficulty selecting among two or more stimuli

Paired Stimuli PresentationSometimes called forced-choice methodPresent two stimuli simultaneously and ask the target person to choose oneEach stimulus is matched to every other stimulus in the setRank order from high, medium, and low preference

Multiple Stimulus PresentationExtension of the paired-stimuli presentationPresent an array of 3 or more stimuli togetherTwo major variations:With replacementStimulus selected remains in array in subsequent trialsWithout replacementSelected stimulus is removed from the array in subsequent trials (takes about half the time to complete the procedure, and it is still fairly accurate)Begin trial with: Which one do you want the most?Repeat several times

GuidelinesMonitor target persons activities prior to assessment Balance cost-benefits of procedures (time to do vs. level of confidence)Balance rankings vs. no rankings with shifts of preferenceWhen time is limited, use fewer stimuli in arrayWhen possible, combine data from multiple assessment procedures

Reinforcer AssessmentIs direct, data-based method Multiple OptionsOne or more stimuli are presentedContingent on a target response, andObserving whether an increase in responding occursAllows you to verify/confirm whether a stimulus functions as a reinforcer

Concurrent Schedule Reinforcer AssessmentPit two stimuli against each other Observe which produces the larger increase in responding

Allows you to determine differences between relative and absolute reinforcement effects

Multiple Schedule Reinforcer AssessmentUse two or more component schedules of reinforcement for a single responseOnly one component schedule is in effect at a given time

An SD signals the presence of each component schedule and is present while that component is in effect

Progressive-Ratio Schedule Reinforcer AssessmentPreferences may change when response requirements increaseProgressive-ratio schedules allows you to assessing stimuli effectiveness as response requirements increase

Response requirements are systematically increased over time until responding declines

Some Guidelines for Using ReinforcementChoose reinforcers relevant to current or creatable establishing operationsMaintain establishing operationsUse high-quality reinforcers of sufficient magnitudeSet an easily achieved initial criterion for reinforcement -criterion should be less than or equal to best performance during baseline

More GuidelinesExplain the contingency and provide prompts to respondDeliver the reinforcer immediately following behaviorReinforce each occurrence of the behavior initiallyUse direct rather than indirect reinforcement contingenciesGradually increase response-to-reinforcement delayUse varied reinforcersUse contingent praise and attentionShift from contrived to naturally occurring reinforcers

Some Cautions Be careful of the schedule you put the person onFR vs. VRSatiation effectsWatch for extinction effects. Can increase bad behavior

Use some common sense.

ConclusionsIs a very powerful techniqueCan usually change all types of behavior

*****************