Binding-problems-and-feature-integration-theory结合问题和特征整合理论资料教学课件

FeaturedetectorsNeuronsthatfiretospecificfeaturesofastimulusPathwayawayfromretinashowsneuronsthatfiretomorecomplexstimuliCellsthatarefeaturedetectors:SimplecorticalcellComplexcorticalcellEnd-stoppedcorticalcellSinglecellrecordingofneuronsinthetemporallobeAnelectrodeisinsertedinthisarea,andmeasureneuralresponseswhenstimuliarechangedgraduallyNeuronsinthisarearespondtocomplexstimulilikethoseshownontheleft.SelectiveadaptationSelectiveadaptationtosize123456789101112123456789101112Figure3.30Howneuronsthatrespondbesttonarrow(N),medium(M),andwide(W)barsrespondtothemedium-bargratingontherightofFigure3.28.(a-b):Responsebeforeadaptation.(c)Responseafteradaptationtothewide-bargratingatthetopleft.(d)Responseafteradaptationtothenarrow-bargratingonthebottomleft.AfterImageAfterimages:RedGreenGreenRedBlueYellowYellowBlueRGBYColorperceptionRGBYadaptationadaptationAfterimageAfterimageBindingproblemTwovisualpathways(what&where/howsystems)ImagefromNeuroscience,2ndEd.(2000).ColumnarorganizationNeuronsthatrespondtothesameorientationarepackedinthesamecolumnImagecourtesyofDr.PaulWellmanandNeuroscience,2ndEd.(2000).Distributedcoding;thenwhatdoyouneed?CombininginputFeatureintegrationtheorybyTreisman&GeladeAttentionplaysacentralroleinsolvingthebindingproblem.Attentionhelpsorganizeinformation.AttentionandFigure-groundsegregationDependingonwhereyoulookat,thefigureandthegroundswitchrapidly.Attentionplayssomeroleindeterminingthefigureandtheground.Attentionand3DstructureDependingonwheretolookat,yougetdifferent3Dstructures.

Damagetotheparietallobecreatesbindingerrors.Copiesoftheblack(A)andthewhite(B)verticalcontour.Copiesoftheblack(A)andthewhite(B)diagonalcontour.Copiesoftheleftsub-figure(A)Therightsubfigure(B)Andthecentralsub-figure(C)FeatureintegrationtheoryAttentionisthe“glue”thatcombinestheinformationfromthewhatandwheresystems.Whatcanyoupredictfromthistheory?Ifyoucan’tattend,youcan’tcombineinformation.IllusionaryconjunctionDemonstrationIwillshowyouascenequickly.Reportfirsttheblacknumbers.Reportwhatyouseeateachofthe4locations.+++Mask+++++Reportfirsttheblacknumbers.Reportwhatyousawateachofthe4locations.IllusionaryconjunctionsWetendtoputdifferentfeaturesfromdifferentobjectstogether.Somebraindamagedpatients(parietallobe)showillusionaryconjunctionsevenwhenthepatientswereallowedtoviewthestimulifor10seconds.VisualsearchexperimentsFeaturesearchThisiseasybecauseyoufindthetargetbylookingforasinglefeature.youdon’tneedattentionConjunctionsearchForthisyouneedtocombinetwoormorefeatures(colorandorientation)youneedattentionLookingforthetargetConjunctionsearchForthisyouneedtocombinetwoormorefeatures(colorandorientation)youneedattentionBecauseyoucanattendanitemoneatatime,thedifficultyintheconjunctionsearchincreasesproportionaltothenumberofitemsinthestimulusframe.Thisisnotthecaseinthefeaturesearch.FindWhichismoredifficult?FindWhichismoredifficult?Featurebindingandattention(Treisman,1988)Experiments:TaskGivenastimulusframecontainingvisualitems,subjectswereaskedtoindicatewhetherornotatargetitemwaspresentintheframe.Target:Target:Target:Target:Featuresearchvs.conjunctionsearchFeaturesearchThetargetitemhasauniquefeature.ConjunctionsearchYouneedtocombinefeaturestofindthetarget.Youneedattention.Becauseyoucanattendonlyoneitematatime,theconjunctionsearchbecomesmoredifficultwhenmoreitemsareinthestimulusframe.Generalityoftheresults:FeaturesearchConjunctionsearchExperiments:Measureaccuracyandresponsetimes(conjunctioncasesvs.non-conjunctioncases)Responsetime#ofdistractors1000ms500msResponsetime#ofdistractors1000ms500msThephysiologyofattentionHowdoyoucombinefeatures?SynchronyhypothesisWhenneuronsindifferentpartsofthecortexarefiringtothesameobject,thepatternoffiringissynchronized(theyfireatthesametime,andinthesamemanner).Sowhenneuronsarefiringinsynchrony,thecorrespondingfeaturesareboundtogether.Separateneuronsrespondtocolor(green,blue,white),contours(orientations),textures,soon.Synchronyhypothesis:Whenthefeaturescomefromthesameobject(i.e.,thewoman),theseneuronsfireatthe