Noncontingent reinforcement as a treatment for severe behavior disorders

64 Pages·1999·1.7 MB·English

by  Kahng, SungWoo

NONCONTINGENTREINFORCEMENTASATREATMENT
FORSEVEREBEHAVIORDISORDERS
By
SUNGWOOKAHNG
ADISSERTATIONPRESENTEDTOTHEGRADUATESCHOOL
OFTHEUNIVERSITYOFFLORIDAINPARTIALFULFILLMENT
OFTHEREQUIREMENTSFORTHEDEGREEOF
DOCTOROFPHILOSOPHY
UNIVERSITYOFFLORIDA
1999
ACKNOWLEDGMENTS
Iwouldliketoexpressmygratitudetoeveryonewhohashelpedmakethis
dissertationpossible.Thankstoallthecurrentandformergraduatesstudentsatthe
FloridaCenteronSelf-Injurywhohelpedtoplanandconductthesestudies:Juliet
Conners,IserDeLeon,Han-LeongGoh,GregoryHanley,JanaLindberg,EileenRoscoe,
RachelThompson,MicheleWallace,andAprilWorsdell.Iwouldalsoliketo
acknowledgethesupportandassistanceofthosewhoservedonmycommittee:Marc
Branch,ShariEllis,TimothyHackenberg,andCecilMercer.Iamparticularlyindebted
tomycommitteechairandadvisor,BrianIwata,forhispatienceandinvaluableguidance
throughoutmygraduatecareer.
Iwouldfurtherliketoexpressgratitudetomyfamilyforprovidingsomuch
supportandencouragement.Finally,IwishtoextendmygratitudetoLisaToolefor
everythingshehasdoneinhelpingmethroughthesepastseveralyears.Withouther
unconditionalloveandsupport,noneofthiswouldhavebeenpossible.
TABLEOFCONTENTS
page
ACKNOWLEDGMENTS
ii
ABSTRACT iv
INTRODUCTION
1
NNThCCerRRapaaessuaatiCFcounnEtcfrtfoeilcotnPs-rbooafcseNeddCurIRnetervention 297
NLiCmRit:atPiaornasmoeftrNiCcRManipulationandProceduralVariations 1124
MechanismsUnderlyingEffectiveness 16
EXPERIMENT1:FUNCTIONALANALYSIS 18
Method 18
ResultsandDiscussion 22
EXPERIMENT2:ACOMPARISONOFPROCEDURES
FORTHINNINGNONCONTINGENT
REINFORCEMENTSCHEDULES 26
Method 27
ResultsandDiscussion 30
EXPERIMENT3:SATIATIONANDEXTINCTIONDURING
NONCONTINGENTREINFORCEMENT 34
Method 36
ResultsandDiscussion 38
GENERALDISCUSSION 48
REFERENCES 51
BIOGRAPHICALSKETCH 56
iii
AbstractofDissertationPresentedtotheGraduateSchool
oftheUniversityofFloridainPartialFulfillmentofthe
RequirementsfortheDegreeofDoctorofPhilosophy
NONCONTINGENTREINFORCEMENTASATREATMENTFORSEVERE
BEHAVIORDISORDERS
By
SungWooKahng
August1999
Chairman:BrianA.Iwata
MajorDepartment:Psychology
Noncontingentreinforcement(NCR)hasbecomeanincreasinglypopular
treatmentforseverebehaviordisorders.NCRinvolvesthedeliveryofreinforcers
independentofresponding,typicallyonatime-ortrial-basedschedule.Thepresent
researchexaminedseveralaspectsofNCRwhenusedasatreatmentforseverebehavior
disorders.
DuringExperiment1,functionalanalysesofself-injuriousbehavior(SIB)or
aggressionwereconductedforfiveindividualsdiagnosedwithmentalretardation.The
assessmentwasusedasascreeningproceduretoidentifythoseindividualswhoengaged
inproblembehaviormaintainedbysocial-positivereinforcement.
TwomethodsofNCRschedulethinningwerecomparedinExperiment2.The
fixedprocedureconsistedofincreasingtheNCRscheduleinfixedincrements.Underthe
adjustingschedule,changeswerebasedonthemeaninterresponsetime(IRT)of
problembehaviors:Asproblembehaviorsdecreased,themeanIRTincreased,resulting
inaleanerNCRschedule.Resultsshowedthatbothprocedureswereeffectivein
IV
suppressingproblembehaviors.Furthermore,theadjustingIRTprocedureledto
thinningoftheNCRschedulethatwasslightlymoreefficientthanthefixedprocedure.
Experiment3examinedifthemechanismofeffectivenessofNCRchangedfrom
satiationtoextinctionastheschedulewasthinned.Determinationoftheoperative
mechanismwasbasedonexaminationofwithin-sessionresponsepatternsobserved
duringtheNCRsessionandtheextinctionsessionthatimmediatelyfollowedit.
SatiationduringNCRwouldleadtoatemporaryincreaseinrespondingduringthePost-
NCR(extinction)session.Alternatively,ifextinctionwasresponsibleforbehavioral
suppressionduringNCR,respondingshouldremainlowduringthePost-NCR
(extinction)sessionbecausethecontingencyfortheproblembehaviorwouldremainthe
sameacrosstheNCRandPost-NCR(extinction)sessions.Resultsshowedthat,for
twoindividuals,themechanismchangedfromsatiationtoextinctionastheNCR
schedulewasthinned.Theresultsfortheotherparticipantsshowedthatsatiationfor
oneindividualandextinctionfortheotherwereresponsibleforbehavioralsuppression
throughoutNCRschedulethinning.
INTRODUCTION
Researchonthetreatmentofseverebehaviordisorders(e.g.,self-injurious
behaviororSIB,aggression,propertydestruction,etc.)hasalong-standinghistoryin
thefieldofbehavioranalysis.Notsurprisingly,muchofthisresearchhasfocusedon
interventionsbasedonthemanipulationofreinforcementcontingenciesthatmay
maintainproblembehavior.Generally,theseinterventionsconsistoftheweakeningof
response-reinforcerrelationshipsand/orestablishmentofalternativeresponsesthat
replacethefunctionoftheproblembehavior.Oneexampleofthistypeofintervention
isdifferentialreinforcementofotherbehavior(DRO),inwhichreinforcementis
deliveredfortheabsenceofresponding(Catania,1998).DRO,alongwithdifferential
reinforcementofalternativebehavior(DRA)andextinction,arethemostcommon
interventionsforseverebehaviordisordersthatinvolvecontingencymanipulation
(Kahng&Iwata,1999).
Incontrasttotheabovetreatmentsforproblembehaviors,noncontingent
reinforcement(NCR)involvesthedeliveryofreinforcersaccordingtoaschedulethatis
independentofresponding.Inrecentyears,therehasbeenarenewedinterestintheuse
ofNCRasatherapeuticintervention(Vollmer,Iwata,Zarcone,Smith,&Mazaleski,
1993).Thepresentresearchexaminesseveralaspectsofthedeliveryofreinforcersin
theabsenceofaknowncontingency(i.e.,NCR)whenusedasatreatmentforsevere
behaviordisorders.
Itshouldbenotedthattheterm"noncontingentreinforcement"isinaccurate
becauseitcontradictsthedefinitionofreinforcement.Thatis,reinforcementby
definition,iscontingentuponaresponse.Additionally,NCRdoesnotleadtoa
1
reinforcementeffectofincreasedresponding;infact,NCRoftenleadstoareductionin
responding.SeveralalternativestothetermNCRhavebeenproposed;theseinclude
fixed-time(FT)reinforcement,response-independentreinforcement,freereinforcement,
andrandomreinforcement.However,thesealternativeterms,allofwhichcontainthe
term"reinforcement,"areasproblematicasNCR.Additionally,thereareseveral
advantagestothetermNCRoverthesuggestedalternatives.First,NCRunambiguously
conveystheabsenceofacontingencybetweenaresponseandthedeliveryofareinforcer.
Second,NCRismoreflexiblethanFTreinforcementbecauseNCRcanalsobedelivered
onvariable-time(VT)ortrial-basedschedules.Third,NCRissynonymouswith
response-independentreinforcement.Finally,NCRismorespecificthanfreeand
randomreinforcement.Infact,randomreinforcementsuggeststheabsenceofaschedule,
whichisnottrueofNCR.
AlthoughthetermNCRmaynotbeanidealterm,itissufficientlydescriptive,as
goodorbetterthanthealternativeterms,andhasprecedentinuseinbothbasic(Lane,
1960)andappliedresearch(Bushell,Wrobel,&Michaelis,1968;Hart,Reynolds,Baer,
Brawley,&Harris,1968).Moreover,thereisprecedentfortheuseofthelabel
"reinforcement"inreferencetoproceduresthatdonotproduceareinforcementeffect.
Forexample,"DRO"isawidelyacceptedterm.Yet,reinforcementisnotdelivered
contingentuponanyparticularresponse.Rather,reinforcementiscontingentonthe
absenceofaparticularresponseandelapsedtime.Furthermore,asinthecaseofNCR,
DROdoesnotleadtoanincreaseinresponding.
NCRasaControlProcedure
TherehasbeenalonghistoryoftheuseofNCRinthefieldofbehavioranalysis.
OnesuchapplicationofNCR,particularlyinbasicoperantresearch,hasbeenasa
contingency-controlprocedure(e.g.,Edwards,Peek,&Wolfe,1970;Lattal,1972).One
ofthefirststudiesthatusedNCRasacontingency-controlprocedureinoperant
researchwasconductedbyRescorlaandSkucy(1969).Theyexaminedtheeffectsof
NCRonbar-pressingexhibitedbymaleratsinaseriesofexperiments.During
Experiment1,barpressingwasmaintainedonavariableinterval(VI)schedule.During
Experiment2,theratsweredividedintofourgroups.Thefirstgroup(GroupVI)
continuedtoreceivereinforcement(foodpellets)onthesameVIscheduleasin
Experiment1.Thesecondgroup(GroupE)nolongerreceivedanyreinforcement(i.e.,
extinction).Groupthree(GroupR)continuedtoreceivefoodpellets.However,the
scheduleofreinforcerdeliverywasyokedtotheVIscheduleofthefirstgroup(Group
VI);therefore,thisgroupreceivedfoodpelletsindependentofbarpressing(i.e.,NCR).
Theproceduresforthelastgroup(GroupD)wasidenticalthoseofGroupR,except
thatreinforcerswereneverdeliveredwithin5secondsofabarpress.Thiscondition
wasdesignedtoruleoutthepossibilityofadventitiousreinforcement.Resultsshowed
thatGroupVIcontinuedtorespondatratessimilartothoseexhibitedduring
Experiment1,whereasrespondingdecreasedfortheotherthreegroups(GroupsE,R,
andD).Furthermore,theoveralldecreaseinrespondingobservedinthesethreegroups
wassimilar,althoughthedecreaseinrespondingforGroupR(i.e.,NCR)wassomewhat
slowerthanthatofGroupE(i.e.,extinction).
Hammond(1980)examinedtheparametriceffectsofacontingencyonfree-
operantrespondingbyvaryingtheprobabilitiesofreinforcementforrespondingandnot
responding.Acontingencywasdefinedasthedifferencebetweentheprobabilityof
reinforcementforrespondingandtheprobabilityofreinforcementfornotresponding.
Thus,adifferencegreaterthanzerowasapositivecontingency,adifferenceequaling
zerowasthecontingency-controlcondition(i.e.,NCR),andadifferencelessthanzero
wasanegativecontingency.
InExperiment1,Hammondexaminedtheeffectsofashiftfromapositive
contingencytoazerocontingencyonresponseratesusing10experimentally-naivemale
rats.Theprobabilitiesofreinforcementforrespondingandnotrespondingunderthe
positivecontingencyconditionwere0.05and0.0,respectively.Underthecontingency-
controlcondition,theprobabilitiesofreinforcementgivenaresponseandnoresponse
wereboth0.05.Thus,thedifferencebetweenthetwoequaledzero.Resultsshoweda
substantialdecreaseinrespondingfollowingtheintroductionofthezerocontingency.
Experiment2examinedresponseratesfollowingashiftfromahighpositivecontingency
toalowerpositivecontingency,toazerocontingency,ortoahighnegative
contingency.Resultsofthisexperimentshowedadecreaseinrespondingthatwasmuch
greaterfollowingashiftfromapositivecontingencytoanegativecontingencythanfrom
apositivecontingencytoazerocontingency.
TheuseofNCRasacontingency-controlprocedurehasnotbeenlimitedtobasic
research.Severalstudieshavedemonstratedthecontingency-controlfeatureofNCRin
appliedresearch.Forexample,Bushelletal.(1968)examinedtheuseofatoken
economytoincreasethestudyingbehaviorofpreschoolagechildren.Deliveryof
tokenswascontingentuponactivelyengaginginindividualactivities(e.g.,Spanish)and
participatinginstudyteams(i.e.,studybehavior),whichresultedinhighlevelsof
studying.Bushelletal.thendeliveredtokensnoncontingently,whichresultedina
subsequentdecreaseinstudying.
Hartetal.(1968)evaluatedtheeffectsofcontingentandnoncontingentsocial
reinforcementoncooperativeplay(e.g.,handingobjectstootherchildren,sharingtoys,
etc.)exhibitedbyafive-yearoldgirl.Duringthecontingentreinforcementphase,a
teachersmiledat,laughedandconversedwith,andadmiredtheparticipantwhenshe
engagedincooperativeplay.Thesamereinforcersweredeliveredatrandomintervals
throughouttheschooldayinthenoncontingentreinforcementcondition.Results
showedanincreasedrateofcooperativeplaywhenreinforcersweredelivered
contingentlyandlowerrateswhenreinforcersweredeliverednoncontingently.
Finally,Goetz,Holmberg,andLeBlanc(1975)comparedDROandNCRas
controlprocedureswhileevaluatingatreatmenttoincreasecompliancewithadult
requests.Theirparticipantwasa3-year-oldchildattendingpreschool.Theauthors
initiallyincreasedcompliancebypresentingverbalpraisecontingentuponeach
occurrenceofcompliance.TheycomparedtheseresultswiththoseobtainedunderNCR
(reinforcementdeliveredfollowingcomplianceandnoncompliance)andDRO
(reinforcementdeliveredcontingentoneveryinstanceofnoncompliance).Responding
wasmorevariableandsuppressionwasslowerunderNCRthanunderDRO.Goetzet
al.concludedthatDROwasthepreferredcontrolprocedure.However,onelimitation
ofthisstudywasthedeliveryofNCRindiscretetrialsinwhichreinforcerswere
deliveredfollowingcomplianceonsometrialsandfollowingnoncomplianceonothers.
Thus,resultsoftheNCR/DROcomparisonweresomewhatconfoundedbecauseNCR
mayhavefunctionedasintermittentreinforcementforcompliance.
ThesestudieshighlightthepotentialfortheuseofNCRasacontingency-control
procedure.DespitenumerousdemonstrationsoftheutilityofNCRinbothbasicand
appliedresearch,extinctioncontinuestobethemostcommoncontrolprocedure.This
maybeafunctionoftheamountofeffortrequiredtoimplementextinctionversusNCR.
Itislikelythatlesseffortisrequiredtodiscontinuethedeliveryofreinforcersthanto
deliverreinforcersindependentofresponding.Thelatterrequiresthattheexperimenter
developanNCRscheduleanddeliverreinforcersbasedonthatschedule,whereasthe
formertypicallyrequireslittleornoresponsebytheexperimenters.However,NCR
mayultimatelybebetterthanextinctionasacontingency-controlprocedurebecauseof
thereducedlikelihoodofsideeffects(e.g.,extinctionbursts)oftenassociatedwith
extinction.
OneareainwhichNCRiscommonlyusedasacontingency-controlprocedureis
inthefunctionalanalysisofseverebehaviordisorders.Thisanalysistypicallyinvolves
thesystematicmanipulationofreinforcementcontingenciessuspectedofmaintainingthe
problembehavior.Testconditionscontaincontingenciesfortheemissionofthetarget
behavior(i.e.,problembehavior),whereasthecontrolconditiondoesnot.Therefore,