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comBehaviouralProcesses78(2008)240–245ShortcommunicationLearning,workingmemory,andintelligencerevisitedElaineTamez,JoelMyerson,SandraHaleDepartmentofPsychology,WashingtonUniversity,OneBrookingsDrive,Box1125,St.
Louis,MO63130,UnitedStatesReceived8September2007;accepted11January2008AbstractBasedonearlyndingsshowinglowcorrelationsbetweenintelligencetestscoresandlearningonlaboratorytasks,psychologiststypicallyhavedismissedtheroleoflearninginintelligenceandemphasizedtheroleofworkingmemoryinstead.
In2006,however,B.
A.
Williamsdevelopedaverballearningtaskinspiredbythree-termreinforcementcontingenciesandreportedunexpectedlyhighcorrelationsbetweenthistaskandRaven'sAdvancedProgressiveMatrices(RAPM)scores[Williams,B.
A.
,Pearlberg,S.
L.
,2006.
Learningofthree-termcontingenciescorrelateswithRavenscores,butnotwithmeasuresofcognitiveprocessing.
Intelligence34,177–191].
Thepresentstudyreplicatedthisnding:Performanceonthethree-termlearningtaskexplainedalmost25%ofthevarianceinRAPMscores.
Addingcomplexverbalworkingmemoryspan,measuredusingtheoperationspantask,didnotimproveprediction.
Notably,thiswasnotduetoalackofcorrelationbetweencomplexworkingmemoryspanandRAPMscores.
Rather,itoccurredbecausemostofthevariancecapturedbythecomplexworkingmemoryspanwasalreadyaccountedforbythethree-termlearningtask.
TakentogetherwiththendingsofWilliamsandPearlberg,thepresentresultsmakeastrongcasefortheroleoflearninginperformanceonintelligencetests.
2008ElsevierB.
V.
Allrightsreserved.
Keywords:Intelligence;Learning;Three-termcontingency1.
IntroductionAlthoughpsychologistsgenerallyagreeontheimportanceofassessingintelligence,therehasneverbeenaconsensusastotheexactnatureofthisconstruct(IntelligenceanditsMeasurement:ASymposium,1921;Neisser,1981;Neisseretal.
,1996;SternbergandDetterman,1986).
Thereisevenalackofagreementonwhetherintelligenceiscomprisedofonefac-tor('g';Jensen,1968;Spearman,1927),twofactors,(e.
g.
,uidvs.
crystallized;HornandCattell,1966),ormanyfactors(e.
g.
,eithermultiplefactorsorahierarchyoffactors;Carroll,1993;Sternberg,1985).
Recently,therehasbeengrowinginterestintherela-tionbetweenworkingmemoryandintelligence.
Indeed,someresearchers(e.
g.
,Engleetal.
,1999;Engle,2002;KyllonenandChristal,1990)haveclaimedthatworkingmemorycapacityisintelligence.
Incontrast,Ackermanetal.
(2002,2005)argued,basedonbothasinglestudyincludinganunusuallylargenum-berofabilitymeasuresandameta-analysisof86samples,thatCorrespondingauthor.
E-mailaddress:emtamez@artsci.
wustl.
edu(E.
Tamez).
workingmemoryandintelligencearenotisomorphic,andthatworkingmemoryisjustoneofanumberofhighlycorrelatedabilities.
Inthemidstofthecontroversyconcerningtheroleofworkingmemoryandintelligence,anewstudybyWilliamsandPearlberg(2006)suggeststhatlearning,inparticularlearningthree-termcontingencies,maybeevenmorepredictivethanworkingmem-oryinpredictingintelligence(Snowetal.
,1984).
TheWilliamsandPearlbergndingsstandincontrasttoearlyndingsshow-inglowcorrelationsbetweenlearningonlaboratorytasksandintelligencetestscores(Woodrow,1938,1946),whichcausedmanyresearcherstodismisstheroleoflearninginintelligence.
Intheirrstexperiment,WilliamsandPearlberg(2006)foundthattheirthree-termlearningtaskcorrelatedwiththeRaven'sAdvancedProgressiveMatrices(RAPM)(Ravenetal.
,1998),buttwootherlearningtasks(i.
e.
,freerecallandpairedasso-ciates)didnot.
Inasecondexperiment,theyobservedthatthethree-termlearningtaskdidnotcorrelatewithworkingmemoryandprocessingspeed,despitethefactthatthesemeasuresalsocorrelatedwiththeRAPM,whichisthe"goldstandard"mea-sureofuidintelligence.
Takentogether,thesendingsstronglysuggestthatlearningmaybeanimportantcontributorofuniquevarianceinintelligencetestscores,contrarytopreviousreports0376-6357/$–seefrontmatter2008ElsevierB.
V.
Allrightsreserved.
doi:10.
1016/j.
beproc.
2008.
01.
008E.
Tamezetal.
/BehaviouralProcesses78(2008)240–245241thatindividualdifferencesinworkingmemorycapacityexplainnearlyallofthevariance.
Moststudiesexaminingthecorrelationsamongseveralcog-nitivetestsreportpositivecorrelationsbetweenallcognitivemeasures(forareview,seeAckermanetal.
,2005),whicharepresumedtoindicatetheexistenceofageneralability("g")com-montoallmeasures(Spearman,1927).
WilliamsandPearlberg'sfailuretondsignicantcorrelationsbetweentheirlearningtaskandspeedandworkingmemoryiscontrarytosuchndings.
Tofurthertestwhetherlearningandworkingmemorymakeinde-pendentcontributionstopredictingperformanceonintelligencetests,thepresentstudyexaminedtherelationbetweenthree-termcontingencylearning(usingbothaverbalandnonverbalversionofthistask),workingmemory(usingbothverbalandnonverbal),anduidintelligence(usingtheRAPM).
2.
Method2.
1.
ParticipantsSixtyWashingtonUniversityundergraduates(30maleand30female)participated.
Participantscompletedahealthquestion-naireformtoscreenforvisualproblems,neurologicaldisease,anddepression.
Inaddition,anearvisionacuitytestwasadmin-isteredusingaWormingtonCard(GuildenOphthalmics,ElkinParks,PA)toensurethatparticipantswouldbeabletoaccuratelyperceivethestimulionthecomputerscreen.
2.
2.
ApparatusStimuliforthecomputerizedtaskswerepresentedona30cm*23cmatscreenmonitorequippedwithTouchwareSoftwareS64SR4(3MTouch,St.
Paul,MN).
AllcomputerizedtaskswereprogrammedinE-prime1.
1(PsychologySoftwareTools,Pittsburgh,PA).
Responsesweremadeeitherusingacom-putermouse,thecomputerkeyboard,orvocally(andrecordedusinganOlympusVN-900PCdigitalrecorder).
2.
3.
ProcedureEachparticipantcompleteda2-hsessionindividually.
Fol-lowingthehealthquestionnaireandvisiontest,participantsperformedthefollowingsequenceoftasks:theWAIS–IIIvocabularytest(PsychologicalCorporation,1997),theverbalthree-termlearningtask,averbalworkingmemorytask,theRAPM,anonverbalthree-termlearningtask,andtwononver-balworkingmemorytasks.
Participantsweregivenabriefbreakevery30minthroughoutthesession.
2.
3.
1.
Verbalthree-termcontingencylearningtaskInthisverballearningtask(WilliamsandPearlberg,2006),participantsweretoldtolearntheassociationsbetweeneachofthetencuewords(e.
g.
,lie)andthelistofthreeassociatedmemoryitems(e.
g.
,fan,rim,dry).
Therewerefourblocksoflearningtrials,eachofwhichwasfollowedbyatestblock.
Boththelearningandtestblockswereself-paced.
Fig.
1.
Examplesoflearningandtesttrialsfromtheverbalthree-termlearningtask.
Onlearningtrials,participantswererstshownacueword(e.
g.
,lie)followedbytheprompt,"pressA",asshowninFig.
1.
Oncetheparticipantpressedthecuedletter,thepromptdisap-pearedandthecuedletter"A"andtheassociatedmemoryitem(e.
g.
,fan)appearedinthebottomrighthandofthescreen.
Thecueword,letter,andthememoryitemremainedonthescreenuntiltheparticipantpressedtheenterkey.
Then,thecueword(i.
e.
,lie)wasshownagainfollowedbythesecondprompt(i.
e.
,"pressB")andafterpressingthecuedletter,theletter"B"andthesecondmemoryitem(e.
g.
,rim)remainedonthescreenuntiltheparticipantpressedenter.
Thethirdprompt(i.
e.
,"pressC")thenappearedbeneaththecueword.
Again,thepromptdisap-pearedoncetheparticipantpressedthecuedletter,andtheletter"C"andthethirdmemoryitem(e.
g.
,dry)appearedinthebot-tomleftofthescreen.
Foreachlearningblock,thiscyclewasrepeateduntilallofthe10cuewordswiththeir3associatedmemoryitemshadbeenpresented.
Theorderofpresentationforthe10cuewordsandtheirassociatedmemoryitemswasdifferentineachofthe4learningblocks.
Ontesttrials,theparticipantviewedacuewordandtherstprompt(i.
e.
,"A"),aswellasatextboxlocatedinthebottomcen-terofthescreen(seeFig.
1).
Theparticipantwasaskedtorecallthewordassociatedwiththecuewordandpromptbytypingthecorrectwordintothetextbox.
Forexample,iftheparticipantsawthecuewordlieandtheletterA,thenthecorrectresponsewastotypethewordfanintothetextbox.
Alternatively,theparticipantcouldtypetheletter"x"intothetextboxiftheassociatedmem-oryitemcouldnotberecalled.
Participantsweregivenfeedbackaftereachresponse(seeFig.
1).
Next,theparticipantwasshownthesamecuewordfollowedbythesecondprompt(i.
e.
,"B")andatextboxandthenthethirdprompt(i.
e.
,"C)andatextbox.
The10cuewordsandthe3promptsconstitutingthetestblockwerepresentedinthesameorderasintheprecedinglearningblock.
FollowingWilliamsandPearlberg(2006),performance242E.
Tamezetal.
/BehaviouralProcesses78(2008)240–245Fig.
2.
Examplesoflearningandtesttrialsfromthenonverbalthree-termlearn-ingtask.
wasmeasuredasthenumberofitemscorrect,summedacrossallfour-testblocks.
2.
3.
2.
Nonverbalthree-termcontingencylearningtaskThistaskwasanonverbaladaptationoftheverbalthree-termlearningtaskthatwasalsoself-pacedandconsistedoffourlearningblocks,eachofwhichwasfollowedbyatestblock.
Theprocedureforthistaskwasidenticaltotheprocedurefortheverbalthree-termlearningtaskwiththeexceptionthatthestimuliwerepatternsandthetesttrialsinvolvedrecognitionratherthanrecall(seeFig.
2).
Testtrialsbeganwiththeparticipantseeingacuepatternandtherstprompt,"A.
"Insteadofatextbox,however,theparticipanthadtoselectthecorrectpattern,usingthecomputermouse,fromninedifferentpatterns(eightofwhichweredis-tractors)displayedina'patternrecognition'boxinthecenterofthescreen(seeFig.
2).
Alternatively,theparticipantcouldselecttheletter"x"ifnoneofthepatternsseemedtobecorrect.
Asintheverballearningtask,participantsweregivencorrec-tivefeedbackaftereachresponse.
Theparticipantthensawthesamecuepatternwiththesecondpromptandrecognitionboxfollowedbythethirdpromptandrecognitionbox.
Thepatternsintherecognitionboxweredifferentforeachcuepatternandpromptbutremainedconstantacrosstrialsalthoughthelocationsofthepatternswithintherecognitionboxvariedrandomly.
Par-ticipantscompletedatotaloffourlearningtrialsandfourtesttrials.
2.
3.
3.
OperationspanInthisverbalworkingmemorytask(TurnerandEngle,1989),participantswereshownaseriesofarithmeticequations,somecorrectandsomenot(e.
g.
,(2*2)+1=4),eachofwhichwasfollowedbyawordtoberecalledattheendoftheseries.
Serieslengthrangedfromtwotosevenitems.
Theserieslengthswerepresentedinarandomorder,whichwasthesameforeachpartici-pant,withtwotrialsateachserieslength.
Participantscompleted6practicetrialswithequationsonlyfollowedby10practicetri-alswithbothequationsandmemoryitemsbeforebeginningtheactualtesttrials.
Eachseriesbeganwithpresentationofagreenxationcross,whichremainedonthescreenuntiltheparticipantpressedthespacebartobegin,atwhichpointanarithmeticequationappeared.
Theparticipantthenreadtheequationaloudandindi-catedwhetheritwascorrectornotbypressingeithertherightorleftmousebutton,respectively.
Iftheparticipantfailedtorespondwithin10s,anerrorwasrecorded.
Followingeachequation,awordwaspresentedinthecenterofthescreenfor1.
5s,andtheparticipantreadthewordaloud.
Attheendoftheseries,participantswereaskedtorecallallofthewordsintheorderinwhichtheyhadappeared.
Afterrecallingasmanywordsaspossible,participantspressedthespacebartobeginthenextseries.
Performancewasmeasuredasmemoryspan,denedasthelongestserieslengththatcouldbereliablyrecalledincorrectorder(fordetailsofthescoringprocedure,seeHaleetal.
,1996).
2.
3.
4.
GridspanInthisnonverbalworkingmemorytask,eachseriesbeganwithagreenxationcrossthatremainedonthescreenuntiltheparticipantstouchedthecrosstobegin.
Participantsthensawaseriesof4*5grids,witharedXappearinginarandomlocationineachgrid.
Eachgridwaspresentedfor1750msfollowedbyablankscreenfor1s.
Attheendofeachseries,participantswereshownanemptygreengridandtouchedallofthelocationswhereanXhadappearedthattheycouldrecall.
Serieslengthrangedfrom2to11items.
Participantscompletedfourpracticetrialsbeforebeginningthetesttrials,consistingoftwotrialsateachserieslengthpresentedinarandomorder.
Performancewasmeasuredasmemoryspan,denedasthelongestserieslengththatcouldbereliablyrecalled,irrespectiveoforder(Haleetal.
,1996).
2.
3.
5.
AlignspanThisnonverbalworkingmemorytaskwassimilartothegridspantaskexceptthatparticipantsperformedasecondarytaskbetweengridpresentations.
Participantssawaseriesof4*5gridscontainingareddotandtwowhitedotsandindi-catedaloudwhetherthedotsformedastraightlineornot.
Eachgridwaspresentedfor2sfollowedbyablankscreenfor1s.
Attheendofeachseries,anemptygreengridwaspresented,andtheparticipanttouchedallthereddotlocationsthatcouldberecalled.
Serieslengthrangedfromtwotoeightitems.
Par-ticipantscompletedfourpracticetrialsbeforebeginningthetesttrials.
Performancewasmeasuredasmemoryspan,denedasthelongestserieslengththatcouldbereliablyrecalled,irrespec-tiveoforder(Haleetal.
,1996).
2.
3.
6.
Raven'sAdvancedProgressiveMatrices(RAPM)Acomputerizedadaptationofthesecondsetof36problemsfromtheRAPMwasused.
Oneachtrial,participantssawa3*3matrixofpatternsfromwhichthelowerright-handpat-ternwasmissing.
Participantsusedthemousetoindicatewhichpatternoutofeightchoicesbestcompletedthematrix.
Alter-natively,theycouldselecta"donotknow"option.
ParticipantsE.
Tamezetal.
/BehaviouralProcesses78(2008)240–245243Fig.
3.
Accuracy(proportioncorrect)byblockontheverbalthree-termlearningtaskandthenonverbalthree-termlearningtask.
Errorbarsindicatestandarderrors.
Table1DescriptivestatisticsforexperimentaltasksTaskMeanS.
D.
RangeOperationspan3.
71.
21.
0–6.
5Gridspan9.
22.
53.
0–14.
0Alignspan5.
11.
71.
0–8.
0RAPM22.
85.
910.
0–33.
0Verballearning,totalcorrect64.
728.
45.
1–116.
1Nonverballearning,totalcorrect40.
619.
93.
9–93.
9weregiven30mintocompletethistask.
Priortothisdeadline,ifaparticipantfailedtoanswerveoutofthelastsixconsecutivetrialscorrectly,thetaskwasautomaticallyterminated.
3.
ResultsPerformanceonboththeverbalandnonverbalthree-termcontingencylearningtasksimprovedoverblocks,butitimprovedatafasterratefortheverballearningtask(seeFig.
3).
Performanceonbothtaskswashighlyconsistentacrossthelastthreeblocks(Cronbach'salpha=.
96and.
89,respectively).
Therewasawiderangeofindividualperformanceonalltasks(seeTable1).
Thetotalscoreontheverballearningtaskwashighlycor-relatedwiththeRAPM(seeTable2fortheinter-correlationsforallthetasks).
TotalscoreonthenonverballearningtaskwasTable2Intercorrelationsbetweenvariables1234561.
Operationspan12.
Alignspan.
258*13.
Gridspan.
391**.
598**14.
Verballearning,total.
457**.
229.
399**15.
Nonverballearning,total.
324*.
124.
292*.
628**16.
RAPM.
395**.
122.
439**.
489**.
369**1*p.
60),suggestthattheverballearningtaskwasabletocap-tureagenerallearningabilitythatpredictsRAPM,anonverbalmeasureofuidintelligence.
Thefactthatthenonverbalthree-termlearningtaskwasnotashighlycorrelatedwiththeRAPMastheverbalthree-termlearn-ingtaskmayreecttherestrictedrangeofscoresarisingfromthedifcultyofthenonverbaltaskaswellasmotivationalprob-lemsarisingfromitsgreaterdifculty(seeTable1andFig.
3).
Indeed,nineparticipants'performanceonthenonverballearn-ingtaskactuallydeclinedfromthersttolasttesttrial,whereasallparticipantsimprovedontheverballearningtask.
Moreover,whenthesenineparticipantswereexcludedfromtheanalysis,thecorrelationbetweenthenonverballearningtaskandRAPMincreasedfrom.
37to.
43.
Animportantgoalforfutureresearchwillbetodevelopaversionofthenonverballearningtaskthatismorecomparabletotheverballearningtaskintermsofthelevelofthedifculty.
Thiswillmakeitpossibletobetterdeter-minewhetherthenonverballearningtaskcanaccountforasmuchRAPM-relatedvarianceastheverballearningtaskandtheextenttowhichthatvarianceissharedbetweenverbalandnonverballearning.
WilliamsandPearlberg(2006)havearguedthatthree-termcontingenciesarebasicunitsoflearning,andthatthestrengthoftherelationbetweenperformanceontheRAPMandwordassociationtask,whichisbasedonsuchcontingencies,isduetotheiruniquecharacteristics.
WilliamsandPearlbergreportedthatsimplelearningtaskssuchaspairedassociatelearningdonotcorrelatewithRAPMwhilethethree-termcontingencylearningtaskdoes,butitremainsunclearwhetherthestrongcorrelationbetweenthisnewlearningtaskandRAPMisdueto"three-termcontingencylearning.
"Onealternativeinterpre-tationmightbethatitisthestructureofthelearningmaterial,whichcouldbethoughtofas10listsof3wordseach,thatiscriti-cal.
Recently,however,Williams(personalcommunication)hasconductedadditionalexperimentsthatmakethis'listoflists'interpretationlesslikely.
Futureresearchincludingadditionalthree-termcontingencytasks,particularlyoneswhicharemoresimilartothekindsofcontingenciesstudiedinresearchonoper-antconditioning,willbeneededinordertoestablisharelationbetweenthree-termcontingencylearninganduidintelligence.
Wewouldemphasize,however,thatwhilethebestinterpretationoftherelationbetweentheverballearningtaskanduidintelli-genceisstillunclear,whatisclearisthattheverbalthree-termcontingencylearningtaskdoescorrelateexceptionallywellwiththeRAPMandcapturesuniquevariancethatisnotcapturedbyothercognitivemeasures.
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