Evaluating-a-Brain-Computer-Interface-to-Categoris

EvaluatingaBrain-ComputerInterfacetoCategoriseHumanEmotionalResponseKatieCrowley,AidanSliney,IanPitt,DaveMurphyDepartmentofComputerScienceUniversityCollegeCorkCork,[e-mail],[e-mail],[e-mail],[e-mail]—TheaimofthisstudyistoevaluateNeuroSky’sMindsetheadsetasaminimallyinvasivemethodofmeasuringtheattentionandmeditationlevelsofasubject.Twopsychologically-basedtestswereconductedtoassessthesuitabilityoftheheadsettomeasureandcategoriseauser’slevelofattentionandmeditation.Keywords-Emotion;Assessment;NeuroSky;Brain-ComputerInterface;Stroop;Stress;Attention;SeriousGames;ComputerAssistedLearningI.INTRODUCTIONAproblemarisesinusingseriousgamestoassesstheuser’semotionalresponse.Ahumanassessorcouldanswerquestionsthatotherformsofassessmentcannot.Wasthestudentnervous?Didthestudentlookstressed?Didtheyshowconfidence?Thisinformationcanbevaluableforformativeassessment.'Eveniftheprimaryassessmentpurposedoesnotincludeemotionalresponse,assecondarydataitcanbeofconsiderablevalue[1].Onesuchemotionthatcouldprovevaluableforassessmentiscalmness.Ouruseoftheterm‘calm’describeshowrelaxedandcomposedauseris.Assessor’sobservationwillalwaysleadthewayinemotionassessment.OuraimforthisstudyistoassessthesuitabilityofNeuroSky’sMindsettocaptureusers’meditationandattentionlevelsinaninstancewhereitisnotpossibletohaveanobserverpresent.TheadvantageandnoveltyofusingNeuroSky’sMindsetBrain-ComputerInterface(BCI)togainemotioninformationliesinthefactthatlearnerscanassessthemselvesatanytimewithouttheneedforassessors.A.NeuroSkyABCIisacommunicationsysteminwhichmessagesorcommandsthatanindividualsendstotheexternalworlddonotpassthroughthebrain'snormaloutputpathwaysofperipheralnervesandmuscles.NeuroSkyhavedevelopedanon-invasive,dry,biosensortoreadelectricalactivityinthebraintodeterminestatesofattentionandrelaxation.NeuroSkyisalow-cost,easytouseElectroEncephalogram(EEC)developedforleisure.Itcapturesneuralactivityusingthreedryelectrodes(locations:beneaththeearsandtheforehead)anddecodesthembyapplyingalgorithms.NeuroSkyprovidesinformationonauser’sDelta,Theta,Alpha,Beta,andGammabrainwavebandpowerlevels[2].B.CapturingEmotionsforAssessmentwithNeuroSkyNeuroSkyreadsattentionandmeditationlevelsdirectlybasedontheuser’sbrainactivity,andoutputsanumberpersecondinascalefrom0to100foreachemotioncaptured.Byusingthesefiguresweplantogroupusersintodifferentattentioncategories.Welookedatthepossibilityoftimestampinganyprecisemomentswhentheusermakesamistake.OurintentionwastofindtheseerrorsbyrecordinganytimesoferraticoutputfromtheMindset.II.METHODSTwopsychologicaltestswerecompletedtoevaluatetheeffectivenessofusingNeuroSky’sMindsetforAssessment;aStrooptestandatestimplementingtheTowersofHanoi.Thetestswerecompletedinablacked-outroom.ThetestswereconductedonaDellT3400withadualmonitorsetup.RecordingswereundertakenusingaShureSM-57microphone.20usersparticipatedinthestudy(20completedtheStroopand17undertookTheTowersofHanoi),witheachtestaveraging20minutes.TheBCIusedtorecordthemeditationandattentionlevelswasNeuroSky’sMindset.Abackupheadsetwasusedtocheckforconsistentcalibration.A.TheStroopTestTheStroopColour-WordInterferenceTest(Stroop,1935[4])isawell-knownpsychologicaltestofselectiveattention,cognitiveflexibilityandprocessingspeed,oftenutilizedasapsychologicalorcognitivestressor[5].Thetestexploitsthefactthat,forexperiencedreaders,thereadingofawordhasbecomeanautomatism.Individualscanreadwordsmuchfasterthantheycanidentifycolours.Theassessmentrequiresthesubjecttonamethecolourthatisdisplayedandnotthewordi.e.toidentifythecolourstimulusandnotthewordstimulus.Theautomaticormostnaturalresponseistodeterminethesemanticmeaningofthewordi.e.readingtheword‘red’thesubjectthinksofthecolour‘red’.Thecognitivemechanisminvolvedinthistaskisdirectedattention,thesubjectmustmanagetheirattentionbyinhibitingoneresponseinordertosayordosomethingelse.Rothkrantzetal.[6]haveusedanadaptationoftheStrooptesttosimulatestressinspeechaspartoftheirstudiesonVoiceStressAnalysis.TheRothkrantzvariationiscomputer-basedandincorporatesagradualincreaseofthelevelofdifficultyinthetestoverafive-minuteperiod.Thedifficultyofthetaskisincreasedasthetimebetweentheappearancesofthecoloursisshortenedeveryminutebyhalfasecond,decreasingfromtwoandahalfsecondintervalsduringminuteone,tointervalsofhalfasecondinminutefive.201010thIEEEInternationalConferenceonAdvancedLearningTechnologies978-0-7695-4055-9/10$26.00©2010IEEEDOI10.1109/ICALT.2010.81276Subjectsarerequiredtospeakthenameofthecolourthatisdisplayedtothem,andthisdataisrecordedforlateranalysis.Inthisstudy,thefirstminuteisconsideredtorepresentnormalconditions.Whentheacousticanalysisofthedatainminuteonewascomparedtothedatainminutefive,anincreaseinfundamentalfrequencywasobserved,asthesubjectbecomesincreasinglystressed.RothkrantzetalsuggestthattheacousticchangesmeasuredduringminutefiveofthistestdemonstrateinducedstresscausedbytheStrooptest.ToexaminetheapplicationoftheNeuroSkyheadsetasameansofmeasuringthemeditationandattentionlevelofasubject,werepeatedRothkrantz’sadaptatio