Spatial Cueing

The spatial cueing or Posner cueing task (Posner, 1980) is a common paradigm for studying visual attention. For the participant, the task is easy: detect ... SpatialCueing Background ThespatialcueingorPosnercueingtask(Posner,1980)isacommonparadigmforstudyingvisualattention.Fortheparticipant,thetaskiseasy:detectwhenatargetstimulusispresented,andrespondasquicklyaspossible.Usually,thestimulusappearseitherontheleftsideortherightofthescreen,andparticipantsarecuedbeforethestimulusappears.Thecueissometimes"exogenous"(e.g.,thecueappearsatthesamelocationastheupcomingstimulus),andsometimes"endogenous"(e.g.,acentrally-presentedarrowpointingtothelocationoftheupcomingstimulus),butinbothcasescuetheparticipanttothepotentialtargetlocation. Theimportantpartaboutthecueingparadigmisthatcuescanbevalidorinvalid.Avalidcueis"correct",inthatanarrowpointingtotheleftsideofthescreenprecedesaleft-sidetarget.Aninvalidcueis"incorrect",inthat(forexample),anarrowcuepointstotheleftsideofthescreenbutprecedesaright-sidetarget.Howdocueschangeresponses?Itdependsonthecontext.Inaparadigmwheremost(say,80%)ofthecuesarevalid,validcuesleadtofasterresponses,andinvalidcuesleadtoslowerresponses(whencomparedtoresponsetimeswhenthereisnocueatall). Posner's(Posner,1980;Posner&Peterson,1990)interpretationofthiscueingeffectisrelatedtotheideaofan"attentionalspotlight."Inessence,Posnersuggestedthatwhenweseeacue,visualattentionisorientedtowardsthatcue,whichhastheeffectofenhancingvisualprocessingatthecued/attendedlocation.Becauseresourcesarelimited(wecan'tenhanceeverythingallthetime),thatenhancementistradedoffagainstadecreaseinvisualprocessingawayfromthecue.Thus,forvalidcues,werespondfasterbecauseattentionhasbeendirectedtothecuedlocationandspeedsprocessing;forinvalidcueswerespondslowerbecauseattentionisdirectedawayfromthetarget,andwemustshiftback. Thetimingofcuesalsoallowsexperimenterstotestthetimescaleofshiftsinvisualattention.Forexample,ifthecueprecedesthetargetbyseveralseconds,thereislittleresponse-timebenefittovalidcues,andlittlecosttoinvalidcues.Thisphenomenonisknownasinhibitionofreturn:whenweattendtoalocation,thevisualsystemtendstoavoidreturningattentiontothatareaforabrieftimeafterwards.Ontheotherendofthetemporalspectrum,cueswithextremelyshortdelays(say,100msbeforethetarget)havenoeffect,presumablybecauseittakesatleastthatlongforourattentiontoshifttothecuedlocation. SequenceofEvents Configurations ExogenousCueing(default) Anexogenousspatialcueingexperimentconsistingof91totaltrials.40trialshaveavalidcue,10trialsaninvalidcue,26trialshavenocue(controltrials),and15are"catch"trialsinwhichthereisnotarget.Thetargetisaredbox.Cuedurationisarandomvaluebetween200and500ms. EndogenousCueing Thisusesthesametiming,conditions,andtrialcountsasthedefaultconfiguration.However,thecueisendogenous(anarrowpointingtotheleftorright,ratherthanastimulusappearingpreciselyatthecuedlocation). References Posner,M.I.(1980).Orientingofattention.QuarterlyJournalofExperimentalPsychology,32,3-25. Posner,M.,&Peterson,S.(1990).Theattentionsystemofthehumanbrain.AnnualReviewofNeuroscience,13,25-42. DataColumns Block PracticeorMain TrialNumber Trialnumberinthecurrentblock CueingCondition EndogenousorExogenouscue CueDuration Duration(inms)ofthecue CueType Left,Right,orNone(nocue) TargetType Left,Right,orNone(notarget/catchtrial) Condition Valid,Invalid,Control,orCatchtrials Response Participant'sresponse(1=targetpresent) ResponseAccuracy Accuracyofresponse RT Reactiontime(inms)