Visual working memory continues to develop through ...

The capacity of visual working memory (VWM) refers to the amount of visual information that can be maintained in mind at once, ... DownloadArticle DownloadPDF ReadCube EPUB XML(NLM) totalviews ViewArticleImpact SHAREON Abstract Introduction Experiment1 Experiment2 GeneralDiscussion ConflictofInterestStatement Acknowledgments References Peoplealsolookedat ORIGINALRESEARCHarticle Front.Psychol.,27May2015Sec.DevelopmentalPsychology https://doi.org/10.3389/fpsyg.2015.00696 Visualworkingmemorycontinuestodevelopthroughadolescence ElifIsbell1*,KeisukeFukuda2,HelenJ.Neville1andEdwardK.Vogel1 1DepartmentofPsychology,UniversityofOregon,Eugene,OR,USA 2DepartmentofPsychology,VanderbiltUniversity,Nashville,TN,USA Thecapacityofvisualworkingmemory(VWM)referstotheamountofvisualinformationthatcanbemaintainedinmindatonce,readilyaccessibleforongoingtasks.Inhealthyyoungadults,thecapacitylimitofVWMcorrespondstoaboutthreesimpleobjects.WhilesomeresearchersarguedthatVWMcapacitybecomesadult-likeinearlyyearsoflife,othersclaimedthatthecapacityofVWMcontinuestodevelopbeyondmiddlechildhood.HereweassessedwhetherVWMcapacityreachesadultlevelsinadolescence.Usinganadaptationofthevisualchangedetectiontask,wemeasuredVWMcapacityestimatesin13-year-olds,16-year-olds,andyoungadults.Wetestedwhetherthecapacityestimatesobservedinearlyorlateryearsofadolescencewerecomparabletotheestimatesobtainedfromadults.OurresultsdemonstratedthatthecapacityofVWMcontinuestodevelopthroughoutadolescence,notreachingadultlevelsevenin16-year-olds.ThesefindingssuggestthatVWMcapacitydisplaysaprolongeddevelopment,similartotheprotractedtrajectoriesobservedinvariousotheraspectsofcognition. Introduction Thecapacityofvisualworkingmemory(VWM)referstotheamountofvisualinformationthatcanbemaintainedinthemindatonce,readilyavailableforrapidaccess(LuckandVogel,2013).IthasbeendemonstratedthatthecapacityofVWMishighlylimited(LuckandVogel,1997;VogelandMachizawa,2004;XuandChun,2006;Awhetal.,2007;ZhangandLuck,2008).Whenprocessingstrategiesarepreventedorcontrolledinyoungadults,thecapacitylimitofVWMcorrespondstoaboutthreesimpleobjects(Pashler,1988;LuckandVogel,1997;Cowan,2001).ElectrophysiologicalandfunctionalmagneticresonanceimagingstudiesprovidefurtherevidenceforsuchlimitedcapacityinVWM(ToddandMarois,2004;VogelandMachizawa,2004).Theestimatesofsuchdiscretecapacitylimitsdiffermarkedlyacrossindividuals(VogelandMachizawa,2004;Rouderetal.,2008).Thesecapacityestimatesstronglypredictfluidintelligenceinadults(Cowanetal.,2005,2006;Fukudaetal.,2010;Unsworthetal.,2014).Furthermore,theVWMcapacityyieldshighcorrelationswithbothintelligenceandaptitudemeasuresinchildren(Cowanetal.,2005,2006).Understandingthedevelopmentofthiscognitiveassetcanshedlightonbothhowsuchcapacitylimitsemergeandhowindividualdifferencesincrucialaspectsofcognitionunfold. WhilesuperiorperformanceinVWMtaskshasbeenassociatedwithfavorablecognitiveandeducationaloutcomes,deficitsinVWMhavebeenobservedinlearningdisabilitiesinreading(Reiteretal.,2005;Gathercoleetal.,2006;WangandGathercole,2013)andmathematics(McLeanandHitch,1999;Ashkenazietal.,2013;Szucsetal.,2013).Inaddition,VWMdeficitshavebeendocumentedinawidespectrumofdisorders,suchasattentiondeficitandhyperactivitydisorders(Martinussenetal.,2005;Lenartowiczetal.,2014)andschizophrenia(Goldman-Rakic,1994;Silveretal.,2003;LeeandPark,2005).CharacterizingthetypicaldevelopmentaltrajectoryofVWMcapacitylimitscanguidetrainingandinterventioneffortsthattargetatypicalpopulationsinwhichVWMdeficitsarecommon.ProfilingwhenandhowVWMcapacitymaturescaninformusaboutwhentheplasticityofVWMislesslikelytobeconstrainedduetomaturationandthesensitiveperiodsduringwhichtrainingandinterventioneffortsaremorelikelytobeeffective. SeveralstudiesfocusedoninvestigatingthetypicaldevelopmentaltrajectoryofVWMcapacity.Oneofthecommonparadigmsusedinthesedevelopmentalstudiesisthevisualchangedetectiontask(LuckandVogel,1997).Inthistask,participantsarebrieflypresentedwithasamplearrayofobjectsoneachtrial.Followingashortretentionperiod,atestarrayispresentedandparticipantsareaskedtojudgewhetherthesamplearrayandthetestarrayareidenticalordifferinonesingleitem.Theperformanceonthesechange-detectionjudgmentsisthenusedtodeterminethenumberofitemsthatcanbeheldinVWM,orinotherwords,anindividual’sVWMcapacity. VariantsofthisparadigmwereemployedininfantstudiestoinvestigatethedevelopmentofVWMduringthefirstyearoflife(Ross-Sheehyetal.,2003,2011;Oakesetal.,2006).Forinstance,Ross-Sheehyetal.(2003)usedalookingpreferenceparadigmtoexploreVWMcapacityininfants.Infantswerepresentedwithtwosimultaneousdisplaysofitems,onewiththesameitemsstreaming,andtheotherwithonerandomitemchangingateachdisplay.LookingpreferencesofinfantsweremeasuredwiththeassumptionthatinfantswouldshowpreferencesforthechangingdisplaysaslongasthenumberofitemsonthedisplayswaswithinornearthecapacityoftheirVWM.Four-and6.5-month-oldinfantswerereportedtodetectchangesonlyatdisplayswithoneitem,whileinfantsasyoungas10monthsofagewerefoundtopreferlookingatchangingdisplaysthatcontaineduptofouritems,butnotsixitems.Basedonthisfinding,itwasconcludedthatinfantsreachedalmostanadult-likeVWMcapacitybytheendofthefirstyear.Employingsimilartasks,Oakesetal.(2006)reportedthateven7.5-month-oldswereabletodetectchangesofcolor-locationcombinationsinarraysofthreeobjects.TogethertheseresultsimplyarapiddevelopmentinstoringmultipleobjectsinVWMduringthefirstyearoflife. However,contrarytotheassertionsthatVWMcapacitydevelopsrapidlytotheextentthatitreachesalmostadultlevelsininfancy,severalstudiesarguedamoreprotracteddevelopment,continuingatleastthroughchildhood.Forinstance,inastudywithanadaptationofthechangedetectiontaskforyoungchildren,3-and4-year-oldchildrenhadlowerVWMcapacityestimatescomparedto5-and7-year-oldchildren,and5-year-oldsperformedsignificantlyworsethan7-year-olds(Simmering,2012).Inasimilarlineofwork,5-year-oldswerefoundtodisplaylowercapacityestimatesthan10-year-oldsacrossvarioussetsizes(Riggsetal.,2006).TheseresultssuggestthatVWMcapacitycontinuestoexpandatleastduringearlychildhoodandcontradicttheclaimsthatVWMcapacitybecomesadult-likeininfancy. Furthermore,whileRiggsetal.(2006)arguedthatVWMcapacityreachedadultlevelsofthreetofouritemsat10yearsofage,otherstudiesreportedlowercapacityestimatesfor10-year-oldscomparedtoadults(Cowanetal.,2006;Riggsetal.,2011).Similarly,inastudycomparing10-to12-year-oldchildrentoyoungerandolderadults,childrendisplayedhighercapacityestimatesthanolderadultsonlywhentheencodingtimeswereshort,butconsistentlyshowedlowercapacityestimatesthanyoungadults(Sanderetal.,2011).Moreover,inacross-sectionalstudy,Cowanetal.(2005)foundlowerVWMcapacityinsixth-gradechildrencomparedtoadults.Inlinewiththesefindings,12-to16-year-oldsadolescentswereshowntohavelowercapacityestimatesthanadultsinachangedetectiontaskwhenthreetargetitemswerepresent(Spronketal.,2012).Likewise,inastudythatassessedVWMperformanceinalargesampleofindividualsbetweentheagesof8and75,apeakinVWMperformancewasreportedaroundage20(BrockmoleandLogie,2013).SuchconvergingevidencefromindependentstudiessuggeststhatVWMcapacityisnotadult-likeinchildhoodandimpliesongoingdevelopmentatleastduringtheearlyyearsofadolescence. Inthepresentstudy,weinvestigatedwhetherVWMcapacityshowsaprotracteddevelopment,extendingfromadolescenceintoadulthood.Adolescenceisatimeperiodduringwhichthebrainexhibitstremendousstructuralchanges(Raznahanetal.,2011).Thecorticalregionsthatareinvolvedinworkingmemoryprocessessuchastheparietalcortexandprefrontalcortex(CurtisandD’Esposito,2003;ToddandMarois,2004)displaymaturationalchangesacrossadolescence(Gieddetal.,1999;LebelandBeaulieu,2011).Especiallytheprefrontalcortexdisplayschangesinvariousfeatures,suchasthecorticalthickness(Sowelletal.,2004;LenrootandGiedd,2006),graymatterdensity(Sowelletal.,2001),andwhitematteranisotropy(Nagyetal.,2004;Barnea-Goralyetal.,2005;Mabbottetal.,2006)wellintoadulthood.Basedonthesefindingsofprolongedbraindevelopmentinadolescence,weexpectedtoobserveimmatureprofilesofVWMinadolescentsascomparedtoadults.Usinganadaptationofthevisualchangedetectiontask(LuckandVogel,1997),withsetsizes2,4,and6,wetestedwhetherthecapacityestimatesobtainedinearlyorlateryearsofadolescencewerecomparabletotheestimatesattainedfromadults. Experiment1 Introduction ToinvestigatewhetherVWMcapacityreachesadultlevelsinearlyorlateryearsofadolescence,werecruited13-and16-year-oldparticipants.Cowanetal.(2005)demonstratedthatsixthgradechildren,rangingfrom11to13yearsofage,didnothavecapacityestimatesashighasadults.Similarly,comparedtoadults,12-to16-year-oldadolescentshadlowercapacityestimateswhenpresentedwiththreeitems(Spronketal.,2012).Expectingtoreplicatethesefindings,weanticipatedobtaininglowercapacityestimatesfrom13-year-oldscomparedtoadults.Moreover,basedontheongoingbraindevelopmentthroughoutadolescenceinregionsassociatedwithWM,weexpectedtoobservelowercapacityestimatesalsoin16-year-oldscomparedtoadults. Method Participants AdolescentparticipantswererecruitedviathedevelopmentaldatabaseoftheUniversityofOregon.Alladolescentparticipantsweremiddleschoolandhighschoolstudents,attendingavarietyofschoolsinEugene,Oregon.Parentswereinterviewedoverthephonetoensuretheirchildrenhadnormalorcorrected-to-normalvisionandweretypicallydevelopingindividualswithnoneurologicaldisorders,developmentaldelays,ADD/ADHD,learningdisabilities,visualtrackingproblems,colorblindness,depressionoranxiety,andhadneverusedanypsychotropicdrugs. AdultparticipantswererecruitedviaflyersfromtheUniversityofOregon.Alladultparticipantswerestudentsattheuniversity.Priortoparticipation,theywereinterviewedtoensurethattheymetallthecriteriathatwereusedtorecruitadolescentparticipants. Thesampleincludedthreeagegroups:twenty-two13-year-olds(M=13.49years;SD=0.30;13females),twenty-two16-year-olds(M=16.58years,SD=0.34;10females),and23adults(M=20.89years,SD=1.32;14females).One13-year-oldparticipantwasnotincludedinthisfinalsampleforperformingbelowchanceathighersetsizes,suggestingahighlikelihoodthatthisparticipantwasnotfullyengagedinthetask. Maternaleducationlevelswerecomparedasaproxyforsocio-economicstatus(SES).Themeanmaternaleducationlevelcorrespondedto“completedsomecollegeclasses”acrosstheagegroups,whichistheequivalentofsomeeducationbeyond12thgradeandattendancetoanypost-secondaryinstitutionintheUnitedStates.Nodifferencesinmaternaleducationwereobservedbetweengroups[F(2,63)=0.85,p=0.43]. ThestudywasconductedwiththeapprovaloftheUniversityofOregonInstitutionalReviewBoard.Writtenassentwasobtainedfromallparticipantsunder18yearsofage,andtheirparentssignedaconsentformfortheirchildren.Participantsolderthan18yearsofagesignedaconsentformtoparticipate.Allparticipantswerepaidfortheirtime. StimuliandProcedure ThetaskwasamodificationofthechangedetectionparadigmusedinLuckandVogel(1997).Stimuliconsistedofcoloredsquares(0.65°×0.65°)superimposedonstickfigures,introducedtotheparticipantsaschildrenwearingcoloredshirts.Eachcoloredsquarewasselectedatrandomfromasetofninecolors(red,pink,violet,blue,green,yellow,orange,brown,andblack).Agivencolordidnotappearmorethanoncewithinanarray.Thememoryarraysincludedsetsizesof2,4,or6stimuli.Theitemsinagivenarraywereseparatedbyatleast3°fromthecenterofeachsquaretothecenteroftheother.Thepositionsofthestimuliwererandomizedoneachtrialtoappearwithina9.8°×7.3°regiononamonitorwithagraybackground,ataviewingdistanceof75cm.Afixationcrosswaspresentedatthecenterofthescreenthroughoutthestudy. Oneachtrial,thefirstarrayofstimuli(thememoryarray)waspresentedfor150ms,followedbya900msblankretentioninterval.ExamplestimuliareshowninFigure1.Aftertheretentioninterval,onlyoneobjectreappearedonthescreen.Inhalfofthetrials,thisobjectwasidenticaltotheobjectthatappearedinthesamelocationwithinthememoryarray.Intheotherhalfofthetrials,theobjectwasadifferentcolorfromtheobjectthatappearedinthesamelocationbefore.Thiswasalwaysanewcolor,notpresentedelsewhereinthedisplaywithinthememoryarray.Participantswereinformedthatineachtrialagroupofchildrenwearingdifferentcoloredshirtsweregoingtocomeuponthescreen,disappearbriefly,andthenonlyonechildwouldcomebacktothescreen,intheexactlocationhewasbefore.Theywereaskedtoindicatewhetherthechildwaswearingthesameshirtorhadchangedhisshirt.Theparticipantsindicatedtheirresponsesusingtheleftandrighttriggersofavideogamecontroller,whichweremarkedas“same”and“change”respectively.Thetestitemremainedonthescreenuntilaresponsewasmade. FIGURE1 Figure1.Examplestimulusdisplays(notdrawntoscale)fora“changetrial”ofsetsize2. Apracticeblockwasadministeredbeforethemaintasktodemonstratethetasktoparticipantsandallowthemtogetmorecomfortableusingtheinterface.Thepracticeblockconsistedofsixtrialsofsetsize2,followedbysixtrialsofsetsize4.Ifaparticipantperformedbelow66%accuracyforeithersetsize,thepracticeblockwasrepeated.Noparticipanthadtorepeatthepracticeblockmorethantwice.Theexperimentconsistedof80trialsofeachsetsizepresentedrandomly,foratotalof240trials.Participantswereofferedabreakevery80trials.Theexperimenttookapproximately12mintocomplete. DataAnalysis VisualworkingmemorycapacitywascalculatedasK=S(H–F),whereKistheVWMcapacity,Sisthesetsizeofthevisualarray,Histhehitrate,andFisthefalsealarmrate(Cowan,2001).UnivariateANOVAswereusedtoexaminetheomnibuseffectsofage.Plannedcontrastswereemployedtocomparethe13-year-oldsversusadults,and16-year-oldsversusadults.Forallplannedcontrastswithp<0.05,Cohen’sd(Cohen,1977;Rosnowetal.,2000)wasreportedasthemeasureofeffectsize. ResultsandDiscussion Capacityestimatesobtainedfromthesetsize2conditionresultedinapotentialunderestimation(i.e.,K<2.00)ofVWMcapacity(Rouderetal.,2008).Nevertheless,todemonstratethatourresultsdidnotdependontheexclusionofthiscondition,wefirstconductedallanalysesincludingthesetsize2conditioninthegrandaveragesofK.MeansandstandarddeviationsofKestimatesarereportedinTable1. TABLE1 Table1.DescriptivesofVWMcapacity(K)estimatesforthethreeagegroupsinExperiment1. TherewasasignificanteffectofageonKestimatesobtainedasanaveragefromallsetsizes,F(2,64)=11.68,p<0.001,ηp2=0.27.Plannedcontrastsrevealedthatthe13-year-oldshadlowerestimatesthanadults,t(64)=–4.86,p<0.001,d=–1.42.Critically,16-year-oldswerealsofoundtoperformworsethanadults,t(64)=–2.20,p=0.031,d=–0.78.However,sincethesetsize2conditionloweredtheKestimatesforeachgroupandthedirectionoftheresultsdidnotappeartodependontheinclusionofthiscondition,weexcludedthisconditioninasecondanalysisoftheeffectofageonoverallK.TheKestimatesobtainedasanaverageofthesetsize4andsetsize6conditionsforthethreeagegroupsareillustratedinFigure2. FIGURE2 Figure2.MeansandstandarderrorsoftheaverageVWMcapacity(K)estimatescomputedbasedonsetsizes4and6forthethreeagegroupsinExperiment1.*p<0.05;**p<0.001. FortheKestimatesexcludingthesetsize2condition,therewasagainasignificanteffectofageonperformance,F(2,64)=11.41,p<0.001,ηp2=0.26.Consistentwiththepreviousfindings,plannedcontrastsrevealedthatboth13-and16-year-oldshadlowerVWMcapacityestimatesthanadults[t(64)=–4.77,p<0.001,d=–1.40,andt(64)=–2.19,p=0.032,d=–0.76,respectively]. Replicatingpreviousfindingswithyoungadolescents(Cowanetal.,2006;Spronketal.,2012),thisexperimentdemonstratedthat13-year-oldsdonothaveadult-likeVWMcapacityestimates.Expandingonthesefindings,thisexperimentalsoshowedthateven16-year-oldshavelowercapacityestimatesthanadults.TheseresultssuggestthatVWMcapacitydoesnotreachadultlevelsinadolescence. Experiment2 Introduction Experiment1providedconfirmatoryevidencethattheestimatesofVWMcapacitydonotreachadultlevelsinearlyadolescence,andthefirstevidencethattheymaynotreachadultlevelseveninlateadolescence.TheseresultscontradicttheclaimsthatVWMcapacityreachesadult-levelsduringearlyyearsoflife.However,itispossiblethatthediscrepancyoffindingsbetweenthesestudiesisatleastpartiallydrivenbydifferencesinthedurationofmemoryarrays.InthestudiesthatclaimedtheVWMcapacityreachedadultlevelsinearlyyearsoflife(Ross-Sheehyetal.,2003;Riggsetal.,2006),thememoryarrayswerepresentedfor500ms.However,wepresentedthememoryarraysfor150msinExperiment1.Toruleoutthepossibilitythatthepoorerperformanceoftheadolescentswasmainlydrivenbyalackofsufficientexposuretothememoryarray,inExperiment2,wepresentedthememoryarraysforbothshortandlongerdurations. TherearecontradictoryfindingsontheeffectsofincreasedpresentationtimeonVWMperformance.Inastudywithyoungadults,increasingthedurationofthememoryarrayfrom100to500mswasnotfoundtoimproveVWMperformance(Vogeletal.,2001).Onthecontrary,inastudythatcomparedtheVWMperformanceinchildren,youngeradults,andolderadults,performancewasfoundtoincreasefrom100to500ms(butnotfrom500to1000ms)forallagegroups(Sanderetal.,2011). Inthisexperiment,weexploredtheeffectsofthedurationofthememoryarrayonVWMinadolescentsandadults.WeaimedtoreplicatethefindingsofExperiment1andalsodetermine(a)whethertheadolescentsbenefitedmorethanadultsfromlongerexposuretimes;and(b)whethertheincreaseinexposuretothememoryarraywassufficienttoeliminatetheagedifferencesinperformanceobservedinthefirstexperiment.InordertoexaminetheeffectsofexposuretimeontheVWMperformanceofadolescentsandadults,wepresentedtheparticipantswithmemoryarraydurationsof150,500,and1000ms,randomlypresentedacrosstrials.Wedidnotuseapresentationtimelongerthan1000mstopreventtheuseofverbalencodingduringmemoryarrays. AnadditionalstrengthofExperiment2,relativetoExperiment1,istheuseofamorepowerfulstatisticaltechnique,multilevelmodeling(MLM),toanalyzethedata.Multilevelmodelingisappropriateinthiscasebecauseourdataarestructuredasresponseswithinindividuals,withdurationasawithin-personindependentvariableandageasabetween-personindependentvariable.Typicallytheclusteringofresponseswithindividualsinrepeated-measuresdesignisaddressedbyaveragingtheresponsesbutthisapproachdiscardspotentiallymeaningfulvariabilityatthewithin-personlevel.Here,MLMallowsustoanalyzeallresponsesforalldurationsandallparticipantsinasingle,powerfulmodel. Method Participants Thefinalsampleincludedtwenty-nine13-year-olds(M=13.41years,SD=0.25;14females),twenty-eight16-year-olds(M=16.48years,SD=0.29;15females),and32adults(M=20.58years,SD=2.09;15females).Allparticipantshadnormalorcorrected-to-normalvisionandweretypicallydevelopingindividualswithnoneurologicaldisorders,ADD/ADHD,learningdisabilities,colorblindness,orvisualtrackingproblems.Alladolescentparticipantsweremiddleschoolandhighschoolstudents,attendingavarietyofschoolsinEugene,Oregon.AlladultparticipantswereUniversityofOregonundergraduates.One13-year-oldparticipantandone16-year-oldparticipantwerenotincludedinthisfinalsampleforperformingbelowchanceathighersetsizes,suggestingthattheseparticipantswerenotfullyengagedinthetask. MaternaleducationlevelswerecomparedasaproxyforSESandnodifferenceswereobservedbetweengroups[F(2,78)=0.52,p=0.60].Theaveragematernaleducationlevelcorrespondedto“completedsomecollegeclasses”acrossagegroups. ThestudywasconductedwiththeapprovaloftheUniversityofOregonInstitutionalReviewBoard.Writtenassentwasobtainedfromallparticipantsunder18yearsofage,andtheirparentssignedaconsentformfortheirchildren.Participantsolderthan18yearsofagesignedaconsentformtoparticipate.Allparticipantswerepaidfortheirtime. StimuliandProcedure TheparadigmdescribedinExperiment1wasmodifiedtoinvestigatetheeffectsofmemoryarraydurationonperformance.Asinthefirstexperiment,thememoryarraysconsistedof2,4,or6itemsondisplay.InExperiment1,Kestimatesfromthesetsize2conditionwasfoundtolowertheoverallcapacityestimatesbutthedirectionoftheresultsdidnotappeartodependontheinclusionofthiscondition.Wekeptthesetsize2conditionintheexperimenttoparallelthedesignfromExperiment1ascloselyaspossible.Thememoryarrayswerepresentedfor150,500,or1000ms.Theexperimentconsistedof120trialsofeachpresentationtime,withboththesetsizesandmemoryarraydurationsrandomizedacrosstrials.Therewereatotalof360trials.Participantswereofferedabreakevery90trials,withapotentialoftakingthreebreaksduringthestudy.Theexperimenttookapproximately20mintocomplete. DataAnalysis Responsetimedataareclusteredwithinsubjectsinthesensethatobservationsfromthesameparticipantaremorehighlycorrelatedwitheachotherthanobservationsfromdifferentparticipants.Thisviolatesthegenerallinearmodelassumptionofindependenceoferrorsattheresponselevel.MLMexplicitlyaddressesthisissuebyseparatelyestimatingthewithin-andbetween-subjecterrorundertheassumptionthatwithin-subjectobservationsarenotindependent(Garson,2013).Accordingly,weusedMLMwithVWMcapacityestimatesnestedinindividualsforthisrepeatedmeasuresdesign.ThemultilevelmodelwasanalyzedwithHierarchicalLinearModeling(HLM)software(RaudenbushandBryk,2002).Thewithin-personpredictor,whichwasduration,wasenteredatLevel1,andthebetween-personpredictor,agegroup,wasenteredatLevel2.Weusedanunstructuredvariance/covariancematrixtoallowforheterogeneouserrorsacrossagegroups.Exposuretimewascenteredat150ms,anddummycodeswereusedtocompare13-year-oldstoadultsaswellas16-year-oldstoadults.Thefollowingmodelwasusedwheretheinterceptandtheslopeswereallowedtovaryrandomly. Level 1:Reponseij=β0i+β1i TIMEij+eijLevel 2:β0i=γ00+γ01*(Early Adolescence)+γ02*(Late Adolescence)+u0iβ1i=γ10+γ11*(Early Adolescence)+γ12*(Late Adolescence)+u1i Inthismodel,Responseijispredictedbyalinearfunctionofexposuretime(TIMEij)fortheVWMcapacityestimateofindividualiatoccasionj.Theintercept(β0i)representstheindividuali’sVWMcapacityestimateat150ms.Theslope(β1i)representstheeffectofexposuretimeonanindividual’sVWMcapacityestimate.ThismultilevelmodelallowedustotestforreplicationofthefindingsfromExperiment1at150ms(theparametersintheβ0equation),andadditionally,whethertherewasamaineffectofexposuretime(γ10)andiftheagegroupsdifferentiallybenefitedfromlongerexposuretothememoryarrays(γ11andγ12).Cohen’sd(Cohen,1977;Rosnowetal.,2000)isreportedforthecomparisonofthedummy-codedgroupsattheintercept(150ms). ResultsandDiscussion MeansandstandarddeviationsofKestimatesarereportedinTable2,separatelyforsetsize4,setsize6,andtheaverageoftheKestimatesfromsetsize4andsetsize6.TheaverageKestimatesforthethreeagegroupsacrossexposureconditionsareillustratedinFigure3. TABLE2 Table2.DescriptivesofVWMcapacity(K)estimatesacrossexposureconditionsinExperiment2. FIGURE3 Figure3.MeansandstandarderrorsoftheVWMcapacity(K)estimatescomputedbasedonsetsizes4and6forthethreeagegroupsacrossexposureconditionsinExperiment2. Althoughthecapacityestimatesobtainedfromthesetsize2conditionresultsinunderestimationofVWMcapacity,todemonstratethatourresultsdidnotdependontheexclusionofthiscondition,onceagainwefirstconductedallanalysesincludingthesetsize2conditioninthegrandaveragesofK. ReplicatingtheresultsfromExperiment1,at150msexposuretimethe13-year-oldsperformedworsethanadults,t(86)=–3.92,p<0.001,d=–1.15.Similarly,inthisshortestdurationcondition,16-year-oldsalsoperformedworsethanadults,t(86)=–2.31,p=0.023,d=–0.57.DurationofthememoryarraydidnothaveasignificanteffectontheincreaseinVWMcapacityinadults,t(86)=1.54,p=0.12.TherewasasignificantdifferenceintherateofincreaseinVWMcapacitybetween13-year-oldsandadults,t(86)=2.31,p=0.023.Therateofincreaseincapacityoverexposuretimedidnotdifferbetween16-year-oldsandadults,t(86)=1.13,p=0.26. Similarly,fortheKestimatesexcludingthesetsize2condition,at150msexposuretimeadultshadhighercapacityestimatesthanboththe13-year-olds[t(86)=3.86,p<0.001,d=1.14]andthe16-year-olds[t(86)=2.50,p=0.015,d=0.56]. AlsofortheKestimatesexcludingthesetsize2condition,durationofthememoryarraydidnothaveasignificanteffectontheincreaseinVWMcapacityinadults,t(86)=1.71,p=0.090.Unliketheanalysesthatincludedsetsize2condition,thedifferenceintherateofincreaseinVWMcapacitybetween13-year-oldsandadultsdidnotreachsignificanceatthep<0.05level,butwasveryclosetothisalphacut-off,t(86)=1.97,p=0.051.Therateofincreaseincapacityoverpresentationtimedidnotdifferbetween16-year-oldsandadults,t(86)=1.31,p=0.19. Totestwhether16-year-oldsperformedworsethanadultsevenatthelongestpresentationcondition,fortheKestimatesexcludingthesetsize2conditionwhichresultsinunderestimationofcapacity,asubsequentmodelwasrun,onceagainwithheterogeneouserrorterms.Tohaveaparsimoniousmodel,astherateofincreaseinVWMoverpresentationtimedidnotdiffersignificantlybetweenthe16-year-oldsandadults,agegroupwasincludedonlyasapredictorofthecapacityestimatesat1000ms,butnotasapredictoroftherateofdecreaseincapacity.Thismodelrevealedthatevenat1000ms,16-year-oldsperformedworsethanadults,t(58)=–2.20,p=0.032,d=–0.41. WhileVogeletal.(2001)reportednoimprovementincapacityfrom100to500msinyoungadults,Sanderetal.(2011)foundanincreaseincapacityfor10-year-olds,youngadults,andolderadultsfrom100to500ms,butnotfrom500to1000ms.Inthisexperiment,wedidnotfindasignificanteffectofexposuretimeforyoungadults.However,aninterestingpatternfortheslopeofincreaseincapacitywasobservedwhentheyoungerandolderadolescentswerecomparedtotheadults.AsshowninFigure3,13-year-oldsshowedthegreatestrateofimprovementincapacitywithlongerexposuretothememoryarray.Youngeradolescentsappearedtobenefitdifferentiallyfromlongerexposuretimethanolderparticipants,whodidnotseemtobenefitmuchfromanincreaseinthedurationofthememoryarray.Thesefindingsimplythatdifferentfactorsaccountforwhyyoungeradolescentsdonotperformatadultlevelsascomparedtoolderadolescents.ItispossiblethatanimmatureprofileinidentifyingandtransferringperceptualrepresentationsintoVWMpartiallyaccountsforthepoorerperformanceofyoungeradolescents,whileolderadolescentsdonotdisplaysuchanimmaturityinencodingprocesses.Inaddition,thematurationlevelsofcorticalstructuresthatshowatemporalactivationprofilenotaccountedforbyperceptualorgeneralattentioneffects,suchastheinferiorfrontaljunctioninthelateralprefrontalcortex(Toddetal.,2011),mayaccountforwhyyoungeradolescentsdifferentiallybenefitfromlongerexposuretothememoryarrays. Despitedifferentiallybenefitingfromlongerexposuretothememoryarray,bothyoungerandolderadolescentsstillperformedworsethanyoungadults.LongerexposuretothememoryarraydiminishedbutdidnoteliminatetheagedifferencesinVWMcapacityobservedinExperiment1.ThesefindingssuggestthatthecapacitydifferencesobservedbetweenadolescentsandadultsinExperiment1werenotdrivensolelybyshortpresentationtimesandsupportthehypothesisthatVWMcapacityhasaprolongeddevelopmentaltrajectory. GeneralDiscussion ThepresentstudyinvestigatedwhetherVWMcapacitycontinuestodevelopthroughadolescenceintoadulthood.Overall,ourresultsdemonstratedthatthecapacityofVWMdoesnotreachadultlevelseitherinearlierorlateryearsofadolescence.Regardlessofwhetherthememoryarraywaspresentedbrieflyorforlongerdurations,neitheryoungernorolderadolescentsdisplayedadult-likecapacityestimates.Ourfindingsareconsistentwithpreviousstudiesthatdemonstratedlowercapacityestimatesinearlyyearsofadolescencecomparedtoadulthood(Cowanetal.,2005;Spronketal.,2012).Hereweextendthesefindingstolateryearsofadolescence,inlinewiththeclaimthatVWMperformanceimprovesthroughoutadolescence(BrockmoleandLogie,2013). OurresultscontradicttheassertionsthatvisualWMcapacityreachesadultlevelsininfancy(Ross-Sheehyetal.,2003;OakesandLuck,2014)ormiddlechildhood(Riggsetal.,2006).ItispossiblethatVWMcapacitydoesnotdevelopinalinearfashion,butratherfollowsaU-shapeddevelopmentaltrajectory,reachinghigherlevelsofperformanceearlierinlifefollowedbyadipinperformanceduringadolescence,andresurgenceintoadulthood.Indeed,thereareexamplesofsuchnon-lineardevelopmentaltrajectoriesinotheraspectsofcognition(Uhlhaasetal.,2009;Dumontheiletal.,2010). However,itisalsolikelythatthediscrepancyoffindingsbetweentheseinfantstudiesandtheotherdevelopmentalstudiesofVWMcapacitystemsfromparadigmdifferences.Instudiesthatemployedavariationofthechangedetectiontask(LuckandVogel,1997)withchildren,adolescents,andadults,participantshavebeenaskedtoverballyormanuallyrespondtoindicatewhetherachangeoccurredinthedisplay(Cowanetal.,2005,2006;Sanderetal.,2011;Spronketal.,2012).However,ininfantstudies,VWMcapacityhasbeenassessedpredominantlywithgazebehaviorofinfants(Ross-Sheehyetal.,2003;Oakesetal.,2013;Kwonetal.,2014).WecannotruleoutthepossibilitythattheresponsecharacteristicsofparadigmsplayaroleinVWMcapacityestimatesobtainedineachstudy.Ithasbeenarguedthatlookingtimeparadigmsmaytapintodifferentcognitiveprocessescomparedtotaskswithovertresponsedemands,yieldingdifferentialperformanceprofiles(Karmiloff-Smith,1992;Hoodetal.,2000;Keen,2003;LeeandKuhlmeier,2013).ItisplausiblethatvariationsofVWMparadigms,regardlessofhowsimilartheyappear,mayhaveinherentdifferencesinwhataspectsofVWMtheymeasure.Infact,studiesthattestedchildren,adolescents,andadultswithsimilartasksandsimilarmethodsofresponseacquisitionconsistentlydemonstratedlowerVWMcapacityestimatesinchildrenandyoungadolescentsascomparedtoadults(Cowanetal.,2005,2006;Sanderetal.,2011;Spronketal.,2012).OurresultsexpandthefindingsofthesestudiesandsuggestthatVWMperformancedevelopsthroughlateryearsofadolescenceintoadulthood. Severalstudiesreporteddevelopmentalchangesforverbalandspatialworkingmemoryspantasksthroughoutadolescence(Kwonetal.,2002;Gathercoleetal.,2004;Lunaetal.,2004;Lucianaetal.,2005;Johnsonetal.,2014).Furthermore,developmentalchangesinadolescencewereobservedforvariousotheraspectsofcognition,suchasdecision-making(CroneandvanderMolen,2004),speedofprocessing(Kail,1991;Ferreretal.,2013),creativethinking(Kleibeukeretal.,2013),andreasoning(Huizengaetal.,2007;Ferreretal.,2013).OurresultssuggestthattheVWMcapacityshowsaprolongeddevelopmentinadolescence,similartothetrajectoriesobservedinotheraspectsofworkingmemory,aswellasvariousothercognitiveabilities. AlthoughourstudyprovidesevidenceforagerelateddifferencesinVWMcapacitybetweenadolescentsandadults,themechanismsunderlyingsuchdifferencesrequirefurtherinvestigation.Adolescenceisapivotalperiodforbraindevelopmentduringwhichsubstantialchangesareobserved(LebelandBeaulieu,2011;Raznahanetal.,2011;Blakemore,2012;Kleinetal.,2014).Previousresearchassociatedchangesinbrainfunctioningfromadolescencetoadulthoodwithdevelopmentalchangesinvisuospatialworkingmemoryperformance(Kwonetal.,2002;Scherfetal.,2006;BungeandWright,2007).ItisplausiblethatchangesinVWMcapacityestimatesfromadolescencetoadulthoodaredrivenbyfunctionalalterationsinthecorticalregionsthatareinvolvedinworkingmemoryprocessessuchastheparietalcortexandprefrontalcortex(CurtisandD’Esposito,2003;ToddandMarois,2004).Inaddition,thesizeanddensityofwhitemattertractsconnectingprefrontal,occipital,parietal,andtemporallobeshavebeenlinkedtoVWMcapacity(Golestanietal.,2014).Aswhitemattermicrostructuresdrasticallytransformthroughoutadolescence(Nagyetal.,2004;Barnea-Goralyetal.,2005;Mabbottetal.,2006),alterationsinwhitematterfromadolescencethroughadulthoodmayalsoaccountfordevelopmentalchangesinVWMcapacity. Potentially,theagerelateddifferencesinVWMcapacityestimatesmaystemfromdisparitiesinattentionskillsratherthangenuinedifferencesinthenumberofslotsavailableinVWM.Attentionalcontrolhasbeenpostulatedasacriticalcomponentofworkingmemory(EngleandKane,2004).Insupportofthisview,poorerattentionalcontrolhasbeenlinkedtolowerVWMcapacityestimates(Vogeletal.,2005;FukudaandVogel,2009,2011;UnsworthandRobison,2014).Inthisregard,havinglowercapacityestimatesonaverage,adolescentsmayactuallyresemblelowcapacityadults.Researchwithadultsdemonstratedthatlow-capacityadultshavepoorerfilteringskills,whichpreventsthemfromexcludingirrelevantitemsfromVWM(Vogeletal.,2005).Furthermore,low-capacityadultsarefoundtorecoverfromattentionalcapturemoreslowlythanhigh-capacityadults(FukudaandVogel,2011).Ifadolescentsaremorelikelowcapacityadultsinperformance,thepoorerperformancetheyexhibitmaybearesultoftheirinefficiencyinusingtheavailableslotsforVWM.Inlinewiththisclaim,inanevent-relatedpotentials(ERP)studywithadolescentsandadults,contralateraldelayactivity(CDA)wasfoundtobelargerinadolescentsthanadultswhentherewereonetargetandtwodistractoritems,asopposedtothesimilarCDAobservedwhentherewasonlyatargetitemondisplay(Spronketal.,2012). However,themechanismsresponsibleforthepoorerperformanceofadolescentsandlowcapacityadultsmayalsobedistinctfromeachother.Forinstance,inastudycomparingolderadultstoyoungeradults,olderadultswerenotsimplylikelowcapacityyoungadults,despiteperformingworsethanyoungeradultsonaverage(Jostetal.,2011).Similarly,inspiteofthesimilaritiesincapacityestimatesbetweenadolescentsandlowercapacityadults,theremaybedifferentialmechanismsdrivingsuchpoorperformance. Alternatively,theobserveddifferencesinperformancemaystemfromagerelateddisparitiesinthenumberofslotsavailableinVWM.Arecentstudywithchildreninvestigatedwhethersuchdisparitiesinavailableslotsaccountfordifferencesinperformancebetweenchildrenandadults(Cowanetal.,2010).Itwasarguedthatinefficiencyofattentioncannotfullyexplaintheobservedagedifferencesinperformanceandthatthereweregenuinestoragedifferencesbetweenchildrenandadults.Accordingly,theremaybedifferencesinhowmanyslotsareavailableinVWMforadolescentsascomparedtoadults.Moreover,theremaybedifferentunderlyingmechanismsthatresultinimmatureprofilesofVWMinyoungerandolderadolescents.Ourresultssuggestedthatyoungeradolescentsbenefitedmorefromlongerexposuretomemorydisplaysthanadults,whileolderadolescentsdidnotshowsuchbenefits.Theseresultsimplydifferentlimitingfactorsforperformanceinearlierandlateryearsofadolescence. InadditiontodifferinginVWMcapacityestimates,adolescentsmaydifferfromadultsintheresolutionofVWMrepresentations.IthasbeendemonstratedthatthenumberofitemsheldinmindforimmediateaccessandtheresolutionoftheserepresentationsaredistinctaspectsofVWM(XuandChun,2006;Awhetal.,2007;Fukudaetal.,2010).Therefore,theremaybedistinctdevelopmentaltrajectoriesforhowmanyitemscanbeheldinworkingmemoryversushowprecisetheserepresentationsare.Whilethenumberofitemsheldinmemoryincreasewithage,theprecisionoftheserepresentationsmayreachadultlevelsearlierduringdevelopment.Onthecontrary,regardlessofdifferentunderlyingneuralmechanisms(XuandChun,2006),bothsystemsthatsupportVWMmayappearimmatureinadolescence. Itisimportanttonotethatinbothstudieswecomparedadolescentstoyoungadults,whowereonaverage20yearsofage.AlthoughithasbeenarguedthatVWMperformancepeaksatage20(BrockmoleandLogie,2013),wecannotascertainthattheyoungadultsinourstudyreflectthepeakVWMperformanceinadulthood.ItispossiblethatVWMcontinuestodevelopintothethirddecadeoflife,reflectingstructuralchangesinbrainmaturationinadulthood(Sowelletal.,2001,2003;LebelandBeaulieu,2011).Inaddition,alloftheadultparticipantsinourexperimentswerecollegestudents.Wematchedtheadolescentsandadultsinourstudybasedonmaternaleducationlevels.However,itshouldbenotedthatthematernaleducationlevelsinoursampleswererelativelyhigh,correspondingtoatleastsomepost-secondaryeducation.Therefore,itremainstobeassessedhowourresultswouldgeneralizetobothyouthandadultsfromdiverseSESbackgrounds.Moreover,amorecomprehensivebatteryofcognitivemeasureswouldberequiredtoruleoutanyconfoundingcognitivedifferencesbetweenadolescentsandadults.FuturestudiesthatincludeawiderrangeofageandSESandmoredetailedcognitiveassessmentscangreatlybenefittheinvestigationoftypicalVWMdevelopmentfromadolescenceintoadulthood.Furthermore,incorporatingneuroimagingmethodscanassistindeterminingthefactorsthataccountforagerelateddifferencesinVWMcapacityestimates. Althoughmuchremainstobeinvestigated,ourstudyprovidesevidenceforaprotracteddevelopmentalprofileofVWMcapacity.Asalatedevelopingsystemthatdoesnotappeartoreachadultlevelseveninlateadolescence,VWMcapacitybearsthepotentialtobearatherplasticsystemindevelopment,malleabletotheeffectsoftheenvironment.Studiesonneuroplasticityacrossdevelopmenthaverepeatedlydemonstratedthatplasticsystemscanbothbecompromisedandenhanceddependingonexperience(StevensandNeville,2009).Therefore,deficienciesinVWMmaybefoundinadolescentswhohaveexperiencedadversitythroughdevelopment.Forinstance,lowermaternaleducationhasbeenassociatedwithpoorerWMperformanceinadolescentsandtheseassociationsappeartobestablethroughadolescence(Hackmanetal.,2014).Targetedscreeningsandinterventionstofollowmaybehelpfulinmitigatingsuchdisparities.DrawingparallelsfromstudiesthatshowchildrenwithpoorWMskillsespeciallybenefitfromadaptiveWMtraining(Holmesetal.,2009),targetedtrainingsmaybeparticularlyeffectiveforadolescentswithlowerVWMcapacity.SinceVWMcapacityisapredictorofacademicachievementinchildren,interventionsthataimtoimproveVWMskillsmayeventuallybecomehelpfultoolsinimprovingtheacademicoutcomesofadolescentswhoareatriskforschoolfailure. ConflictofInterestStatement Theauthorsdeclarethattheresearchwasconductedintheabsenceofanycommercialorfinancialrelationshipsthatcouldbeconstruedasapotentialconflictofinterest. Acknowledgments ThisworkwassupportedthroughNIH/NIDCDR01-000481toHN,andONRN000141210972andNIMHR01-MH087214toEV.WethankthemembersoftheBrainDevelopmentLabfortheirsupportandassistanceindatacollection,ElliotBerkman,TheodoreBellandJasonIsbellforhelpfulcommentsonanearlierversionofthemanuscript. References Ashkenazi,S.,Rosenberg-Lee,M.,Metcalfe,A.W.,Swigart,A.G.,andMenon,V.(2013).Visuo-spatialworkingmemoryisanimportantsourceofdomain-generalvulnerabilityinthedevelopmentofarithmeticcognition.Neuropsychologia51,2305–2317.doi:10.1016/j.neuropsychologia.2013.06.031 PubMedAbstract|CrossRefFullText|GoogleScholar Awh,E.,Barton,B.,andVogel,E.K.(2007).Visualworkingmemoryrepresentsafixednumberofitemsregardlessofcomplexity.Psychol.Sci.18,622–628.doi:10.1111/j.1467-9280.2007.01949.x PubMedAbstract|CrossRefFullText|GoogleScholar Barnea-Goraly,N.,Menon,V.,Eckert,M.,Tamm,L.,Bammer,R.,Karchemskiy,A.,etal.(2005).Whitematterdevelopmentduringchildhoodandadolescence:across-sectionaldiffusiontensorimagingstudy.Cereb.Cortex15,1848–1854.doi:10.1093/cercor/bhi062 PubMedAbstract|CrossRefFullText|GoogleScholar Blakemore,S.-J.(2012).Imagingbraindevelopment:theadolescentbrain.Neuroimage61,397–406.doi:10.1016/j.neuroimage.2011.11.080 PubMedAbstract|CrossRefFullText|GoogleScholar Brockmole,J.R.,andLogie,R.H.(2013).Age-relatedchangeinvisualworkingmemory:astudyof55,753participantsaged8–75.Front.Psychol.4:12.doi:10.3389/fpsyg.2013.00012 PubMedAbstract|CrossRefFullText|GoogleScholar Bunge,S.A.,andWright,S.B.(2007).Neurodevelopmentalchangesinworkingmemoryandcognitivecontrol.CurrOpin.Neurobiol.17,243–250.doi:10.1016/j.conb.2007.02.005 PubMedAbstract|CrossRefFullText|GoogleScholar Cohen,J.(1977).StatisticalPowerAnalysisfortheBehavioralSciences,Rev.Edn.Hillsdale:LawrenceErlbaumAssociates,Inc. GoogleScholar Cowan,N.(2001).Themagicalnumber4inshort-termmemory:areconsiderationofmentalstoragecapacity.Behav.BrainSci.24,87–114;discussion114–185.doi:10.1017/s0140525x01003922 PubMedAbstract|CrossRefFullText|GoogleScholar Cowan,N.,Elliott,E.M.,ScottSaults,J.,Morey,C.C.,Mattox,S.,Hismjatullina,A.,etal.(2005).Onthecapacityofattention:itsestimationanditsroleinworkingmemoryandcognitiveaptitudes.Cogn.Psychol.51,42–100.doi:10.1016/j.cogpsych.2004.12.001 PubMedAbstract|CrossRefFullText|GoogleScholar Cowan,N.,Fristoe,N.M.,Elliott,E.M.,Brunner,R.P.,andSaults,J.S.(2006).Scopeofattention,controlofattention,andintelligenceinchildrenandadults.Mem.Cogn.34,1754–1768.doi:10.3758/BF03195936 PubMedAbstract|CrossRefFullText|GoogleScholar Cowan,N.,Morey,C.C.,Aubuchon,A.M.,Zwilling,C.E.,andGilchrist,A.L.(2010).Seven-year-oldsallocateattentionlikeadultsunlessworkingmemoryisoverloaded.Dev.Sci.13,120–133.doi:10.1111/j.1467-7687.2009.00864.x PubMedAbstract|CrossRefFullText|GoogleScholar Crone,E.A.,andvanderMolen,M.W.(2004).Developmentalchangesinreallifedecisionmaking:performanceonagamblingtaskpreviouslyshowntodependontheventromedialprefrontalcortex.Dev.Neuropsychol.25,251–279.doi:10.1207/s15326942dn2503_2 PubMedAbstract|CrossRefFullText|GoogleScholar Curtis,C.E.,andD’Esposito,M.(2003).Persistentactivityintheprefrontalcortexduringworkingmemory.TrendsCogn.Sci.7,415–423.doi:10.1016/S1364-6613(03)00197-9 CrossRefFullText|GoogleScholar Dumontheil,I.,Houlton,R.,Christoff,K.,andBlakemore,S.J.(2010).Developmentofrelationalreasoningduringadolescence.Dev.Sci.13,F15–F24.doi:10.1111/j.1467-7687.2010.01014.x PubMedAbstract|CrossRefFullText|GoogleScholar Engle,R.W.,andKane,M.J.(2004).“Executiveattention,workingmemorycapacity,andatwo-factortheoryofcognitivecontrol,”inThePsychologyofLearningandMotivation,ed.B.Ross(NewYork,NY:AcademicPress),145–199. GoogleScholar Ferrer,E.,Whitaker,K.J.,Steele,J.S.,Green,C.T.,Wendelken,C.,andBunge,S.A.(2013).Whitemattermaturationsupportsthedevelopmentofreasoningabilitythroughitsinfluenceonprocessingspeed.Dev.Sci.16,941–951.doi:10.1111/desc.12088 PubMedAbstract|CrossRefFullText|GoogleScholar Fukuda,K.,Vogel,E.,Mayr,U.,andAwh,E.(2010).Quantity,notquality:therelationshipbetweenfluidintelligenceandworkingmemorycapacity.Psychon.Bull.Rev.17,673–679.doi:10.3758/17.5.673 PubMedAbstract|CrossRefFullText|GoogleScholar Fukuda,K.,andVogel,E.K.(2009).Humanvariationinoverridingattentionalcapture.J.Neurosci.29,8726–8733.doi:10.1523/JNEUROSCI.2145-09.2009 PubMedAbstract|CrossRefFullText|GoogleScholar Fukuda,K.,andVogel,E.K.(2011).Individualdifferencesinrecoverytimefromattentionalcapture.Psychol.Sci.22,361–368.doi:10.1177/0956797611398493 PubMedAbstract|CrossRefFullText|GoogleScholar Garson,G.D.(2013).“Fundamentalsofhierarchicallinearandmultilevelmodeling,”inHierarchicalLinearModeling,ed.G.D.Garson(ThousandOaks,CA:SagePublications,Inc.),3–25. GoogleScholar Gathercole,S.E.,Alloway,T.P.,Willis,C.,andAdams,A.-M.(2006).Workingmemoryinchildrenwithreadingdisabilities.J.Exp.ChildPsychol.93,265–281.doi:10.1016/j.jecp.2005.08.003 PubMedAbstract|CrossRefFullText|GoogleScholar Gathercole,S.E.,Pickering,S.J.,Ambridge,B.,andWearing,H.(2004).Thestructureofworkingmemoryfrom4to15yearsofage.Dev.Psychol.40,177–190.doi:10.1037/0012-1649.40.2.177 PubMedAbstract|CrossRefFullText|GoogleScholar Giedd,J.N.,Blumenthal,J.,Jeffries,N.O.,Castellanos,F.X.,Liu,H.,Zijdenbos,A.,etal.(1999).Braindevelopmentduringchildhoodandadolescence:alongitudinalMRIstudy.Nat.Neurosci.2,861–863.doi:10.1038/13158 PubMedAbstract|CrossRefFullText|GoogleScholar Goldman-Rakic,P.S.(1994).Workingmemorydysfunctioninschizophrenia.J.NeuropsychiatryClin.Neurosci.6,348–357.doi:10.1176/jnp.6.4.348 PubMedAbstract|CrossRefFullText|GoogleScholar Golestani,A.M.,Miles,L.,Babb,J.,Castellanos,F.X.,Malaspina,D.,andLazar,M.(2014).Constrainedbyourconnections:whitematter’skeyroleininterindividualvariabilityinvisualworkingmemorycapacity.J.Neurosci.34,14913–14918.doi:10.1523/JNEUROSCI.2317-14.2014 PubMedAbstract|CrossRefFullText|GoogleScholar Hackman,D.A.,Betancourt,L.M.,Gallop,R.,Romer,D.,Brodsky,N.L.,Hurt,H.,etal.(2014).Mappingthetrajectoryofsocioeconomicdisparityinworkingmemory:parentalandneighborhoodfactors.ChildDev.85,1433–1445.doi:10.1111/cdev.12242 PubMedAbstract|CrossRefFullText|GoogleScholar Holmes,J.,Gathercole,S.E.,andDunning,D.L.(2009).Adaptivetrainingleadstosustainedenhancementofpoorworkingmemoryinchildren.Dev.Sci.12,F9–F15.doi:10.1111/j.1467-7687.2009.00848.x PubMedAbstract|CrossRefFullText|GoogleScholar Hood,B.,Carey,S.,andPrasada,S.(2000).Predictingtheoutcomesofphysicalevents:two-year-oldsfailtorevealknowledgeofsolidityandsupport.ChildDev.71,1540–1554.doi:10.1111/1467-8624.00247 PubMedAbstract|CrossRefFullText|GoogleScholar Huizenga,H.M.,Crone,E.A.,andJansen,B.J.(2007).Decision-makinginhealthychildren,adolescentsandadultsexplainedbytheuseofincreasinglycomplexproportionalreasoningrules.Dev.Sci.10,814–825.doi:10.1111/j.1467-7687.2007.00621.x PubMedAbstract|CrossRefFullText|GoogleScholar Johnson,E.L.,Singley,A.T.M.,Peckham,A.D.,Johnson,S.L.,andBunge,S.A.(2014).Task-evokedpupillometryprovidesawindowintothedevelopmentofshort-termmemorycapacity.Front.Psychol.5:218.doi:10.3389/fpsyg.2014.00218 PubMedAbstract|CrossRefFullText|GoogleScholar Jost,K.,Bryck,R.L.,Vogel,E.K.,andMayr,U.(2011).Areoldadultsjustlikelowworkingmemoryyoungadults?Filteringefficiencyandagedifferencesinvisualworkingmemory.Cereb.Cortex21,1147–1154.doi:10.1093/cercor/bhq185 PubMedAbstract|CrossRefFullText|GoogleScholar Kail,R.(1991).Developmentalchangeinspeedofprocessingduringchildhoodandadolescence.Psychol.Bull.109,490–501.doi:10.1037/0033-2909.109.3.490 PubMedAbstract|CrossRefFullText|GoogleScholar Karmiloff-Smith,A.(1992).BeyondModularity:ADevelopmentalPerspectiveonCognitiveScience.Cambridge,MA:MITPress. GoogleScholar Keen,R.(2003).Representationofobjectsandeventswhydoinfantslooksosmartandtoddlerslooksodumb?Curr.Dir.Psychol.Sci.12,79–83.doi:10.1111/1467-8721.01234 CrossRefFullText|GoogleScholar Kleibeuker,S.W.,DeDreu,C.K.,andCrone,E.A.(2013).Thedevelopmentofcreativecognitionacrossadolescence:distincttrajectoriesforinsightanddivergentthinking.Dev.Sci.16,2–12.doi:10.1111/j.1467-7687.2012.01176.x PubMedAbstract|CrossRefFullText|GoogleScholar Klein,D.,Rotarska-Jagiela,A.,Genc,E.,Sritharan,S.,Mohr,H.,Roux,F.,etal.(2014).Adolescentbrainmaturationandcorticalfolding:evidenceforreductionsingyrification.PLoSONE9:e84914.doi:10.1371/journal.pone.0084914 PubMedAbstract|CrossRefFullText|GoogleScholar Kwon,H.,Reiss,A.L.,andMenon,V.(2002).Neuralbasisofprotracteddevelopmentalchangesinvisuo-spatialworkingmemory.Proc.Natl.Acad.Sci.U.S.A.99,13336–13341.doi:10.1073/pnas.162486399 PubMedAbstract|CrossRefFullText|GoogleScholar Kwon,M.K.,Luck,S.J.,andOakes,L.M.(2014).Visualshort-termmemoryforcomplexobjectsin6-and8-month-oldinfants.ChildDev.85,564–577.doi:10.1111/cdev.12161 PubMedAbstract|CrossRefFullText|GoogleScholar Lebel,C.,andBeaulieu,C.(2011).Longitudinaldevelopmentofhumanbrainwiringcontinuesfromchildhoodintoadulthood.J.Neurosci.31,10937–10947.doi:10.1523/JNEUROSCI.5302-10.2011 PubMedAbstract|CrossRefFullText|GoogleScholar Lee,J.,andPark,S.(2005).Workingmemoryimpairmentsinschizophrenia:ameta-analysis.J.Abnorm.Psychol.114,599–611.doi:10.1037/0021-843X.114.4.599 PubMedAbstract|CrossRefFullText|GoogleScholar Lee,V.,andKuhlmeier,V.A.(2013).Youngchildrenshowadissociationinlookingandpointingbehaviorinfallingevents.Cogn.Dev.28,21–30.doi:10.1016/j.cogdev.2012.06.001 CrossRefFullText|GoogleScholar Lenartowicz,A.,Delorme,A.,Walshaw,P.D.,Cho,A.L.,Bilder,R.M.,Mcgough,J.J.,etal.(2014).Electroencephalographycorrelatesofspatialworkingmemorydeficitsinattention-deficit/hyperactivitydisorder:vigilance,encoding,andmaintenance.J.Neurosci.34,1171–1182.doi:10.1523/JNEUROSCI.1765-13.2014 PubMedAbstract|CrossRefFullText|GoogleScholar Lenroot,R.K.,andGiedd,J.N.(2006).Braindevelopmentinchildrenandadolescents:insightsfromanatomicalmagneticresonanceimaging.Neurosci.Biobehav.Rev.30,718–729.doi:10.1016/j.neubiorev.2006.06.001 PubMedAbstract|CrossRefFullText|GoogleScholar Luciana,M.,Conklin,H.M.,Hooper,C.J.,andYarger,R.S.(2005).Thedevelopmentofnonverbalworkingmemoryandexecutivecontrolprocessesinadolescents.ChildDev.76,697–712.doi:10.1111/j.1467-8624.2005.00872.x PubMedAbstract|CrossRefFullText|GoogleScholar Luck,S.J.,andVogel,E.K.(1997).Thecapacityofvisualworkingmemoryforfeaturesandconjunctions.Nature390,279–281.doi:10.1038/36846 PubMedAbstract|CrossRefFullText|GoogleScholar Luck,S.J.,andVogel,E.K.(2013).Visualworkingmemorycapacity:frompsychophysicsandneurobiologytoindividualdifferences.TrendsCogn.Sci.17,391–400.doi:10.1016/j.tics.2013.06.006 PubMedAbstract|CrossRefFullText|GoogleScholar Luna,B.,Garver,K.E.,Urban,T.A.,Lazar,N.A.,andSweeney,J.A.(2004).Maturationofcognitiveprocessesfromlatechildhoodtoadulthood.ChildDev.75,1357–1372.doi:10.1111/j.1467-8624.2004.00745.x PubMedAbstract|CrossRefFullText|GoogleScholar Mabbott,D.J.,Noseworthy,M.,Bouffet,E.,Laughlin,S.,andRockel,C.(2006).Whitemattergrowthasamechanismofcognitivedevelopmentinchildren.Neuroimage33,936–946.doi:10.1016/j.neuroimage.2006.07.024 PubMedAbstract|CrossRefFullText|GoogleScholar Martinussen,R.,Hayden,J.,Hogg-Johnson,S.,andTannock,R.(2005).Ameta-analysisofworkingmemoryimpairmentsinchildrenwithattention-deficit/hyperactivitydisorder.J.Am.Acad.ChildAdolesc.Psychiatry44,377–384.doi:10.1097/01.chi.0000153228.72591.73 PubMedAbstract|CrossRefFullText|GoogleScholar McLean,J.F.,andHitch,G.J.(1999).Workingmemoryimpairmentsinchildrenwithspecificarithmeticlearningdifficulties.J.Exp.ChildPsychol.74,240–260.doi:10.1006/jecp.1999.2516 PubMedAbstract|CrossRefFullText|GoogleScholar Nagy,Z.,Westerberg,H.,andKlingberg,T.(2004).Maturationofwhitematterisassociatedwiththedevelopmentofcognitivefunctionsduringchildhood.J.Cogn.Neurosci.16,1227–1233.doi:10.1162/0898929041920441 PubMedAbstract|CrossRefFullText|GoogleScholar Oakes,L.M.,Baumgartner,H.A.,Barrett,F.S.,Messenger,I.M.,andLuck,S.J.(2013).Developmentalchangesinvisualshort-termmemoryininfancy:evidencefromeye-tracking.Front.Psychol.4:697.doi:10.3389/fpsyg.2013.00697 PubMedAbstract|CrossRefFullText|GoogleScholar Oakes,L.M.,andLuck,S.J.(2014).“Short-termmemoryininfancy,”inTheWileyHandbookontheDevelopmentofChildren’sMemory,Vols.1and2,edsP.J.BauerandR.Fivus(NewYorkNY:OxfordUniversityPress),151–180. GoogleScholar Oakes,L.M.,Ross-Sheehy,S.,andLuck,S.J.(2006).Rapiddevelopmentoffeaturebindinginvisualshort-termmemory.Psychol.Sci.17,781–787.doi:10.1111/j.1467-9280.2006.01782.x PubMedAbstract|CrossRefFullText|GoogleScholar Pashler,H.(1988).Familiarityandvisualchangedetection.Atten.Percept.Psychophys.44,369–378.doi:10.3758/BF03210419 CrossRefFullText|GoogleScholar Raudenbush,S.W.,andBryk,A.S.(2002).HierarchicalLinearModels:ApplicationsandDataAnalysisMethods.ThousandOaks,CA:Sage. GoogleScholar Raznahan,A.,Shaw,P.,Lalonde,F.,Stockman,M.,Wallace,G.L.,Greenstein,D.,etal.(2011).Howdoesyourcortexgrow?J.Neurosci.31,7174–7177.doi:10.1523/JNEUROSCI.0054-11.2011 PubMedAbstract|CrossRefFullText|GoogleScholar Reiter,A.,Tucha,O.,andLange,K.W.(2005).Executivefunctionsinchildrenwithdyslexia.Dyslexia11,116–131.doi:10.1002/dys.289 PubMedAbstract|CrossRefFullText|GoogleScholar Riggs,K.J.,Mctaggart,J.,Simpson,A.,andFreeman,R.P.(2006).Changesinthecapacityofvisualworkingmemoryin5-to10-year-olds.J.Exp.ChildPsychol.95,18–26.doi:10.1016/j.jecp.2006.03.009 PubMedAbstract|CrossRefFullText|GoogleScholar Riggs,K.J.,Simpson,A.,andPotts,T.(2011).Thedevelopmentofvisualshort-termmemoryformultifeatureitemsduringmiddlechildhood.J.Exp.ChildPsychol.108,802–809.doi:10.1016/J.Jecp.2010.11.006 PubMedAbstract|CrossRefFullText|GoogleScholar Rosnow,R.L.,Rosenthal,R.,andRubin,D.B.(2000).Contrastsandcorrelationsineffect-sizeestimation.Psychol.Sci.11,446–453.doi:10.1111/1467-9280.00287 PubMedAbstract|CrossRefFullText|GoogleScholar Ross-Sheehy,S.,Oakes,L.M.,andLuck,S.J.(2003).Thedevelopmentofvisualshort-termmemorycapacityininfants.ChildDev.74,1807–1822.doi:10.1046/j.1467-8624.2003.00639.x PubMedAbstract|CrossRefFullText|GoogleScholar Ross-Sheehy,S.,Oakes,L.M.,andLuck,S.J.(2011).Exogenousattentioninfluencesvisualshort-termmemoryininfants.Dev.Sci.14,490–501.doi:10.1111/j.1467-7687.2010.00992.x PubMedAbstract|CrossRefFullText|GoogleScholar Rouder,J.N.,Morey,R.D.,Cowan,N.,Zwilling,C.E.,Morey,C.C.,andPratte,M.S.(2008).Anassessmentoffixed-capacitymodelsofvisualworkingmemory.Proc.Natl.Acad.Sci.U.S.A.105,5975–5979.doi:10.1073/pnas.0711295105 PubMedAbstract|CrossRefFullText|GoogleScholar Sander,M.C.,Werkle-Bergner,M.,andLindenberger,U.(2011).Bindingandstrategicselectioninworkingmemory:alifespandissociation.Psychol.Aging26,612–624.doi:10.1037/a0023055 PubMedAbstract|CrossRefFullText|GoogleScholar Scherf,K.S.,Sweeney,J.A.,andLuna,B.(2006).Brainbasisofdevelopmentalchangeinvisuospatialworkingmemory.J.Cogn.Neurosci.18,1045–1058.doi:10.1162/jocn.2006.18.7.1045 PubMedAbstract|CrossRefFullText|GoogleScholar Silver,H.,Feldman,P.,Bilker,W.,andGur,R.C.(2003).Workingmemorydeficitasacoreneuropsychologicaldysfunctioninschizophrenia.Am.J.Psychiatry160,1809–1816.doi:10.1176/appi.ajp.160.10.1809 PubMedAbstract|CrossRefFullText|GoogleScholar Simmering,V.R.(2012).Thedevelopmentofvisualworkingmemorycapacityduringearlychildhood.J.Exp.ChildPsychol.111,695–707.doi:10.1016/j.jecp.2011.10.007 PubMedAbstract|CrossRefFullText|GoogleScholar Sowell,E.R.,Peterson,B.S.,Thompson,P.M.,Welcome,S.E.,Henkenius,A.L.,andToga,A.W.(2003).Mappingcorticalchangeacrossthehumanlifespan.Nat.Neurosci.6,309–315.doi:10.1038/nn1008 PubMedAbstract|CrossRefFullText|GoogleScholar Sowell,E.R.,Thompson,P.M.,Leonard,C.M.,Welcome,S.E.,Kan,E.,andToga,A.W.(2004).Longitudinalmappingofcorticalthicknessandbraingrowthinnormalchildren.J.Neurosci.24,8223–8231.doi:10.1523/JNEUROSCI.1798-04.2004 PubMedAbstract|CrossRefFullText|GoogleScholar Sowell,E.R.,Thompson,P.M.,Tessner,K.D.,andToga,A.W.(2001).Mappingcontinuedbraingrowthandgraymatterdensityreductionindorsalfrontalcortex:inverserelationshipsduringpostadolescentbrainmaturation.J.Neurosci.21,8819–8829. PubMedAbstract|GoogleScholar Spronk,M.,Vogel,E.K.,andJonkman,L.M.(2012).Electrophysiologicalevidenceforimmatureprocessingcapacityandfilteringinvisuospatialworkingmemoryinadolescents.PLoSONE7:e42262.doi:10.1371/journal.pone.0042262 PubMedAbstract|CrossRefFullText|GoogleScholar Stevens,C.,andNeville,H.(2009).“Profilesofdevelopmentandplasticityinhumanneurocognition,”inTheCognitiveNeurosciencesIV,ed.M.Gazzaniga(Cambridge:MITPress),165–181. GoogleScholar Szucs,D.,Devine,A.,Soltesz,F.,Nobes,A.,andGabriel,F.(2013).Developmentaldyscalculiaisrelatedtovisuo-spatialmemoryandinhibitionimpairment.Cortex49,2674–2688.doi:10.1016/j.cortex.2013.06.007 PubMedAbstract|CrossRefFullText|GoogleScholar Todd,J.J.,Han,S.W.,Harrison,S.,andMarois,R.(2011).Theneuralcorrelatesofvisualworkingmemoryencoding:atime-resolvedfMRIstudy.Neuropsychologia49,1527–1536.doi:10.1016/j.neuropsychologia.2011.01.040 PubMedAbstract|CrossRefFullText|GoogleScholar Todd,J.J.,andMarois,R.(2004).Capacitylimitofvisualshort-termmemoryinhumanposteriorparietalcortex.Nature428,751–754.doi:10.1038/nature02466 PubMedAbstract|CrossRefFullText|GoogleScholar Uhlhaas,P.J.,Roux,F.,Singer,W.,Haenschel,C.,Sireteanu,R.,andRodriguez,E.(2009).Thedevelopmentofneuralsynchronyreflectslatematurationandrestructuringoffunctionalnetworksinhumans.Proc.Natl.Acad.Sci.U.S.A.106,9866–9871.doi:10.1073/pnas.0900390106 PubMedAbstract|CrossRefFullText|GoogleScholar Unsworth,N.,Fukuda,K.,Awh,E.,andVogel,E.K.(2014).Workingmemoryandfluidintelligence:capacity,attentioncontrol,andsecondarymemoryretrieval.Cogn.Psychol.71,1–26.doi:10.1016/j.cogpsych.2014.01.003 PubMedAbstract|CrossRefFullText|GoogleScholar Unsworth,N.,andRobison,M.K.(2014).Individualdifferencesintheallocationofattentiontoitemsinworkingmemory:evidencefrompupillometry.Psychon.Bull.Rev.22,757–765.doi:10.3758/s13423-014-0747-6 PubMedAbstract|CrossRefFullText|GoogleScholar Vogel,E.K.,andMachizawa,M.G.(2004).Neuralactivitypredictsindividualdifferencesinvisualworkingmemorycapacity.Nature428,748–751.doi:10.1038/nature02447 PubMedAbstract|CrossRefFullText|GoogleScholar Vogel,E.K.,Mccollough,A.W.,andMachizawa,M.G.(2005).Neuralmeasuresrevealindividualdifferencesincontrollingaccesstoworkingmemory.Nature438,500–503.doi:10.1038/nature04171 PubMedAbstract|CrossRefFullText|GoogleScholar Vogel,E.K.,Woodman,G.F.,andLuck,S.J.(2001).Storageoffeatures,conjunctionsandobjectsinvisualworkingmemory.J.Exp.Psychol.Hum.Percept.Perform.27,92–114.doi:10.1037/0096-1523.27.1.92 PubMedAbstract|CrossRefFullText|GoogleScholar Wang,S.,andGathercole,S.E.(2013).Workingmemorydeficitsinchildrenwithreadingdifficulties:memoryspananddualtaskcoordination.J.Exp.ChildPsychol.115,188–197.doi:10.1016/j.jecp.2012.11.015 PubMedAbstract|CrossRefFullText|GoogleScholar Xu,Y.,andChun,M.M.(2006).Dissociableneuralmechanismssupportingvisualshort-termmemoryforobjects.Nature440,91–95.doi:10.1038/nature04262 PubMedAbstract|CrossRefFullText|GoogleScholar Zhang,W.,andLuck,S.J.(2008).Discretefixed-resolutionrepresentationsinvisualworkingmemory.Nature453,233–235.doi:10.1038/nature06860 PubMedAbstract|CrossRefFullText|GoogleScholar Keywords:visualworkingmemory,workingmemorycapacity,adolescence,cross-sectional,prolongeddevelopment Citation:IsbellE,FukudaK,NevilleHJandVogelEK(2015)Visualworkingmemorycontinuestodevelopthroughadolescence.Front.Psychol.6:696.doi:10.3389/fpsyg.2015.00696 Received:03March2015;Accepted:11May2015;Published:27May2015. Editedby:YusukeMoriguchi,JoetsuUniversityofEducation,Japan Reviewedby:RichardAllen,UniversityofLeeds,UKHeatherM.Conklin,St.JudeChildren’sResearchHospital,USA Copyright©2015Isbell,Fukuda,NevilleandVogel.Thisisanopen-accessarticledistributedunderthetermsoftheCreativeCommonsAttributionLicense(CCBY).Theuse,distributionorreproductioninotherforumsispermitted,providedtheoriginalauthor(s)orlicensorarecreditedandthattheoriginalpublicationinthisjournaliscited,inaccordancewithacceptedacademicpractice.Nouse,distributionorreproductionispermittedwhichdoesnotcomplywiththeseterms. *Correspondence:ElifIsbell,DepartmentofPsychology,UniversityofOregon,1227UniversityofOregon,Eugene,OR97403,USA,[email protected] Peoplealsolookedat Download