Ruff+Experimental+Design+认知神经科学实验设计.ppt

ExperimentalDesign,ChristianRuffWiththanksto:RikHensonDanielGlaser,Realignment,Smoothing,Normalisation,Generallinearmodel,Statisticalparametricmap(SPM),Imagetime-series,Parameterestimates,Designmatrix,Template,Kernel,Gaussianfieldtheory,pthreshold?”Choiceoftestdependsonhypothesisandcongruenceofcontrasts;theglobalnulltestismoresensitive(i.e.,whendirectionofeffectshypothesised),Twoflavoursofinferenceaboutconjunctions,Fristonetal.(2005).Neuroimage,25:661-7.Nicholsetal.(2005).Neuroimage,25:653-60.,Overview,CategoricaldesignsSubtraction-Pureinsertion,evoked/differentialresponsesConjunction-TestingmultiplehypothesesParametricdesignsLinear-Adaptation,cognitivedimensionsNonlinear-Polynomialexpansions,neurometricfunctionsFactorialdesignsCategorical-InteractionsandpureinsertionParametric-Linearandnonlinearinteractions-PsychophysiologicalInteractions,ParametricDesigns:GeneralApproach,Parametricdesignsapproachthebaselineproblemby:Varyingastimulus-parameterofinterestonacontinuum,inmultiple(n2)steps.andrelatingblood-flowtothisparameterFlexiblechoiceoftestsforsuchrelations:LinearNonlinear:Quadratic/cubic/etc.Data-driven“(e.g.,neurometricfunctions)Model-based,Adaptation:Lineareffectsoftime?,Alinearparametriccontrast,Adaptation:Nonlineareffectsoftime?,Anonlinearparametriccontrast,InvertedUresponsetoincreasingwordpresentationrateintheDLPFC,SPMF,Polynomialexpansion:f(x)b1x+b2x2+.upto(N-1)thorderforNlevels,E.g,F-contrast010onQuadraticParameter=,Nonlinearparametricdesignmatrix,(SPM8GUIofferspolynomialexpansionasoptionduringcreationofparametricmodulationregressors),Linearchange,Quadraticchange,Meanresponse,ParametricDesigns:Neurometricfunctions,Rees,G.,etal.(1997).Neuroimage,6:27-78,versus,InvertedUresponsetoincreasingwordpresentationrateintheDLPFC,Rees,G.,etal.(1997).Neuroimage,6:27-78,ParametricDesigns:Neurometricfunctions,CodingoftactilestimuliinAnteriorCingulateCortex:Stimulus(a)presence,(b)intensity,and(c)painintensityVariationofintensityofaheatstimulusappliedtotherighthand(300,400,500,and600mJ),Bcheletal.(2002).TheJournalofNeuroscience,22:970-6,Assumptions:,ParametricDesigns:Neurometricfunctions,Bcheletal.(2002).TheJournalofNeuroscience,22:970-6,Stimuluspresence,Painintensity,Stimulusintensity,ParametricDesigns:Model-basedregressors,Seymour,ODoherty,etal.(2004).Nature.,Overview,CategoricaldesignsSubtraction-Pureinsertion,evoked/differentialresponsesConjunction-TestingmultiplehypothesesParametricdesignsLinear-Adaptation,cognitivedimensionsNonlinear-Polynomialexpansions,neurometricfunctionsFactorialdesignsCategorical-InteractionsandpureinsertionParametric-Linearandnonlinearinteractions-PsychophysiologicalInteractions,ColoursObjectsColoursObjects,interactioneffect(TaskxStimuli),Viewing,Naming,Factorialdesigns:MaineffectsandInteractions,Maineffectoftask:(A1+B1)(A2+B2)Maineffectofstimuli:(A1+A2)(B1+B2)Interactionoftaskandstimuli:Canshowafailureofpureinsertion(A1B1)(A2B2),Interactionsandpureinsertion,Object-naming-specificactivations,Context:nonamingnaming,adjustedrCBF,ComponentsVisualprocessingVObjectrecognitionRPhonologicalretrievalPInteractionRxPInteraction(nameobject-colour)-(viewobject-colour)1-100-001-1=P,R,V+RxP-P,V-R,V-V=RxP,Interactionsandpureinsertion,Interactions:simpleandcross-overWecanselectivelyinspectourdataforoneortheotherbymaskingduringinference,A1A2B1B2,A1A2B1B2,Overview,CategoricaldesignsSubtraction-Pureinsertion,evoked/differentialresponsesConjunction-TestingmultiplehypothesesParametricdesignsLinear-Adaptation,cognitivedimensionsNonlinear-Polynomialexpansions,neurometricfunctionsFactorialdesignsCategorical-InteractionsandpureinsertionParametric-Linearandnonlinearinteractions-PsychophysiologicalInteractions,AlinearTime-by-ConditionInteraction(“differenceinadaptationforrepeatingvsgenerating”),Contrast:531-1-3-5-11=-55-33-111-13-35-5,LinearParametricInteraction,FactorialDesignwith2factors:Gen/Rep(Categorical,2levels)Time(Parametric,6levels)Timeeffectsmodelledwithbothlinearandquadraticcomponents,NonlinearParametricInteraction,Overview,CategoricaldesignsSubtraction-Pureinsertion,evoked/differentialresponsesConjunction-TestingmultiplehypothesesParametricdesignsLinear-Adaptation,cognitivedimensionsNonlinear-Polynomialexpansions,neurometricfunctionsFactorialdesignsCategorical-InteractionsandpureinsertionParametric-Linearandnonlinearinteractions-PsychophysiologicalInteractions,Parametric,factorialdesign,inwhichonefactorisapsychologicalcontext.andtheotherisaphysiologicalsource(activityextractedfromabrainregionofinterest),Psycho-physiologicalInteraction(PPI),Parametric,factorialdesign,inwhichonefactorisapsychologicalcontext.andtheotherisaphysiologicalsource(activityextractedfromabrainregionofinterest),Psycho-physiologicalInteraction(PPI),AttentionalmodulationofV1-V5contribution,Psycho-physiologicalInteraction(PPI),001,SPMZ,AttentionalmodulationofV1-V5contribution,attention,noattention,V1activity,V5activity,time,V1activity,Psycho-physiologicalInteraction(PPI),Stimuli:Facesorobjects,PPC,IT,Psycho-physiologicalInteraction(PPI),001,adjustedrCBF,medialparietalactivity,Faces,Objects,Stimuli:Facesorobjects,PPC,IT,SPMZ,Psycho-physiologicalInteraction(PPI),PPIstestedbyaGLMwithform:y=(V1A).b1+V1.b2+A.b3+ec=100However,theinteractiontermofinterest,V1A,istheproductofV1activityandAttentionblockAFTERconvolutionwithHRFWearereallyinterestedininteractionatneurallevel,but:(HRFV1)(HRFA)HRF(V1A)(unlessAlowfrequency,e.g.,blocked;mainlyproblemforevent-relatedPPIs)SPM8caneffectadeconvolutionofphysiologicalregressors(V1),beforecalculatinginteractiontermandreconvolvingwiththeHRFthe“PPIbutton”,Psycho-physiologicalInteraction(PPI),Overview,CategoricaldesignsSubtraction-Pureinsertion,evo