Haveyoueverbeensoabsorbedinaconversationatapartythatyoufailedtonoticethatsomeonenewisstandingonlysixinchesawayfromyoutryingtogetyourattention?It’spossiblethatyouweresodistractedthatyoudidn’tnoticeso

　　Haveyoueverbeensoabsorbedinaconversationatapartythatyoufailedtonoticethatsomeonenewisstandingonlysixinchesawayfromyoutryingtogetyourattention?It’spossiblethatyouweresodistractedthatyoudidn’tnoticesomeoneapproachingyou.Butit’salsoentirelylikelythatyouwereexperiencingchangeblindness.

　　Changeblindnessisaphenomenonthatoccurswhenapersonisunabletonoticevisualchangesintheirenvironmentdespitethefactthattheyareoftenratherobvious.Incasesofchangeblindnessthepersonisn’tfailingtonoticesmallorinsignificantchangesbutwillprobablymissbigchangeslikesomeonestandingnexttothemwavingtheirhand.

　　Earlyexperimentswithchangeblindnessfocusedlargelyonmemoryandperceptionwhenviewingpictures.ForexampleapersonmightbeshownaphotographofastreetsceneinEgyptandtoldtomemorizetheimage.Followingthattheywouldbeshownthesamepicturewithcertainelementsaddedortakenawayandaskedtoidentifywhat’sdifferent.Veryoftentheindividualcouldrecallthelargeraspectsofthepicturebutcouldn’trecognizethesmallerchanges.

　　Inthe1990sresearcherDanielSimonsconductedafascinatingstudyintochangeblindnessthatmanypeoplefindunbelievable.InSimons’studyheaskedparticipantstowatchavideoofabasketballbeingpassedaroundbetweenseveralpeoplewithaparticularfocusonthebasketballitself.WhentheexperimentwasoverSimonsfoundthatalargenumberofparticipantsweresofocusedonwatchingthebasketballbeingpassedaroundthattheyfailedtonoticeamaninagorillasuitjumpingaroundinfrontofthecamera.

　　It’simportanttonotethatthechangeinSimons’videowasn’tsubtle;thegorillaisveryobviouslytakingupmuchoftheframe.Simonsconcludedthatparticipantswereexperiencinginattentionalblindnesswhichiswhenapersonfailstonoticeamajorchangebecausetheyaresofocusedonanothertask.Inthiscasebecauseparticipantswereaskedtofocusonthemovementofthebasketballtheirbrainsprioritizedthattaskinordertodoitproperlytherebymissingtheotherthingshappeninginthevideo.

　　InthecaseofSimons’studyparticipantsengagedwhat’sreferredtoasattentionalselectionwhichiswhenapersonselectscertainthing