Detecting Unspecified Familiar FacesEmilyX.Meschke1*,CatrinaM.Hacker1,JordanJ.Juarez1,RafaelS.Maarek2,IrvingBiederman1,31NeuroscienceProgram,2DepartmentofBiomedicalEngineering,3DepartmentofPsychology,UniversityofSouthernCalifornia

ImageUnderstandingLab

1. Cananunspecifiedfamiliarcelebrity—any celebrity—bedetectedamongfacesofnon-celebritiesatRSVPrates?–YES

2. DoCongenitalProsopagnosics(CPs)performworsethancontrolsonthistask?–YES,butCPsperformremarkablywellonthistask—betterthanonnon-speededcelebrity

recognitiontasks!

3. Isdetectionmediatedbyageneralfamiliaritysignal,notlinkedtotheidentificationofthetarget?–NO.DetectionisoverwhelminglyassociatedwithIdentification,evenforCPs.

4. Howdoessuchdetectionofcelebrityfacescomparetoperformanceonnegativedetectionofobjects(e.g.,anunspecifiedobjectthatisnotatool)?

–Objectsaremuchmoreeasilydetectable

*emeschke@usc.edu

http://geon.usc.edu/

Conclusions1. Subjectswereabletodetectcelebritytargetfaces—withoutthe

celebritybeingspecifiedpriortothesequence—atRSVPrates.Thisisinstarkcontrasttowhatisobservedintheidentificationoffamiliarvoiceswhereperformancenosedivestonearchancelevelswithjustahandfulofpossiblevoices.

2. InneithertheRSVPnortheDoppelgängertaskwasthereanyevidencethatthesubjectscouldavailthemselvesofafamiliaritysignal.

RSVPTask:Whensubjectsmadeapositivedetectiontheywerenearlyalwaysabletoprovideanaccurateidentificationofthetarget.DoppelgängerTask:Prosopagnosicswereatorbelowchanceintheircelebritydiscriminationaccuracy.

ReferencesIntraub,H.(1981).Identificationandprocessingofbrieflyglimpsedvisualscenes.InD.F.Fisher,R.A.Monty,&J.W.Senders(eds.),Eyemovements:cognitionandvisualperception.Hillsdale,N.J.:Lawrenceerlbaumassociates.Tranel,D.&Damasio,A.R.(1985).Knowledgewithoutawareness:anautomaticindexoffacialrecognitionbyprosopagnosics.Science,vol.228,1453-1455.AcknowledgmentsNSFBCS0617699;DornsifeResearchFund.

Subjects7 “Moderate”CongenitalProsopagnosics(mCPs):USCstudents(Age19to22years,5female)selectedasCPsbasedontheirperformanceon:a)thefaceblind.org survey(<70),b)theCambridgeFaceMemoryTest(<70),c)theUSCImageUnderstandingLabCelebrityTest(<80),d)thePI20(>50),andunremarkableneurologicalhistory.

48Controls:USCundergraduates,(Age18to47years,35female)withscoresinthenormalrangeontheabovemeasuresoffacerecognitionability.

1“Extreme”CongenitalProsopagnosic (GJ): MaleAge33,faceblind.org survey:18%,CambridgeFaceMemoryTest:28%,USCImageUnderstandingLabCelebrityTest:25%,andPI20:90.

1“Extreme”AcquiredProsopagnosic (MJH): MaleAge53,faceblind.org survey:3%,CambridgeFaceMemoryTest:38%, USCImageUnderstandingLabCelebrityTest:26%,andPI20:83.Alsoevidencessomesimultagnosia.

Detectionisalmostalwaysaccompaniedbyidentification

Thereisthusnoevidenceforafamiliaritysignal(Tranel &Damasio,1985)independentofidentification.

Celebritydetectionimproveswithhigher

ratedfamiliarityPriortotheRSVPandDoppelgänger Discriminationtrials,subjectsweregiventhenamesofthecelebritiesandratedtheirfrequencyofhavingseenthefaces(1=low;5=high).

DoppelgängerDiscriminationTask

Subjectsviewed100pairsoffaces,oneofwhichwasacelebrity.Thenon-celebrityheadshotwasselectedtobeassimilarasreasonablypossiblegiventhesamplingoftheheadshotgalleriesofnon-celebrities.Thephotogenicqualityofthenon-celebrityheadshotswereindistinguishablefromthecelebrities,andnoneofthefacesunderwentremovalofhairoralterationoffaceshapeasintheCFMT.Nolimitwasimposedonthetimerequiredforaresponse.

CorrectAnswer:Right CorrectAnswer:Left

PercentIdentificationfollowing

AccurateDetection

Controls ControlsCPs CPs

(QuestionsandOurAnswers)TheDetectionofanUnspecifiedFamiliarFace

RSVPTasks200RSVPsequenceseachwith30images.Agivensequenceconsistedentirelyofeitherfacesorobjects.

Bothtaskscouldberegardedas“NegativeDetection”(Intraub,1981)inthatthesubjecthadtodetectanobjectthatwasnotaninstanceofaprespecified category(e.g.,“NotanArticleofClothing”),andforfaces,acelebrity—anycelebrity—amongnon-celebrities.Atargetwaspresentinhalfthesequences,thoughneverinthefirstorlastsiximages.Thesubjecthadtoreportwhatorwhothetargetwas,e.g.,“anaxe”or“LeonardoDiCaprio”orsomeidentifyinginformation,e.g.,“TheguyinTitanic.”Categoriesforobjectswereclothing,plants,tools,animals,andmodesoftransportation.Onanygivenobjecttrial,animagefromanyofthesecategoriesmightbeusedasatarget.

ObjectTrials:Allsubjectsperformednearceiling.

FaceTrials:BothControlsandmCPs performedwellabovechanceonnegativedetectionoffaces,withtheControlssuperiortoCPs.

Objects

RSVPCelebrityDetectionandNegativeObjectDetectionTask

chance

FacesControls

mCPs

xCP (GJ)

PresentationRates

Faces Objects

RSVPPros

DoppelgängerControls

DoppelgängerPros

RSVPControls

Scanforacopy!