文稿说明成果tpo 13 3 methods of studying infant perception

MethodsofStudyingInfantInthestudyofperceptualabilitiesofinfants,anumberoftechniquesareusedtodetermineinfants'responsestovariousstimuli.Becausetheycannotverbalizeorfilloutquestionnaires,indirecttechniquesofnaturalisticobservationareusedastheprimarymeansofdeterminingwhatinfantscansee,hear,feel,andsoforth.Eachofthesemethodscomparesaninfant'sstatepriortotheintroductionofastimuluswithitsstateduringorimmediayfollowingthestimulus.Thedifferencebetweenthetwomeasuresprovidestheresearcherwithanindicationofthelevelanddurationoftheresponsetothestimulus.Forexample,ifauniformlymovingpatternofsomesortispassedacrossthevisualfieldofaneonate(newborn),repetitivefollowingmovementsoftheeyeoccur.Theoccurrenceoftheseeyemovementsprovidesevidencethatthemovingpatternisperceivedatsomelevelbythenewborn.Similarly,changesintheinfant'sgenerallevelofmotoractivity—turningthehead,blinkingtheeyes,crying,andsoforth—havebeenusedbyresearchersasvisualindicatorsoftheinfant'sperceptualabilities.Suchtechniques,however,havelimitations.First,theobservationmaybeunreliableinthattwoormoreobserversmaynotagreethattheparticularresponseoccurred,ortowhatdegreeitoccurred.Second,responsesaredifficulttofy.Oftentherapidanddiffusemovementsoftheinfantmakeitdifficulttogetanaccuraterecordofthenumberofresponses.Thethird,andmostpotent,limitationisthatitisnotpossibletobecertainthattheinfant'sresponsewasduetothestimuluspresentedortoachangefromnostimulustoastimulus.Theinfantmayberespondingtoaspectsofthestimulusdifferentthanthoseidentifiedbytheinvestigator.Therefore,whenobservationalassessmentisusedasatechniqueforstudyinginfantperceptualabilities,caremustbetakennottoovergeneralizefromthedataortorelyononeortwostudiesasconclusiveevidenceofaparticularperceptualabilityoftheinfant.Observationalassessmenttechniqueshave emuchmoresophisticated,reducingthelimitationsjustpresented.Filmysisoftheinfant'sresponses,heartandrespirationratemonitors,andnonnutritivesuckingdevicesareusedaseffectivetoolsinunderstandinginfantperception.Filmysispermitsresearcherstocarefullystudytheinfant'sresponsesoverandoverandinslowmotion.Precisemeasurementscanbemadeofthelengthandfrequencyoftheinfant'sattentionbetweentwostimuli.Heartandrespirationmonitorsprovidetheinvestigatorwiththenumberofheartbeatsorbreathstakenwhenanewstimulusispresented.Numericalincreasesareusedasfiableindicatorsofheightenedinterestinthenewstimulus.Increasesinnonnutritivesuckingwerefirstusedasanassessmentmeasurebyresearchersin1969.Theydevisedanapparatusthatconnectedababy'spacifiertoacountingdevice.Asstimuliwerepresented,changesintheinfant'ssuckingbehaviorwererecorded.Increasesinthenumberofsuckswereusedasanindicatoroftheinfant'sattentiontoorpreferenceforagivenvisualTwoadditionaltechniquesofstudyinginfantperceptionhavecomeintovogue.Thefirstisthehabituation-dishabituationtechnique,inwhichasinglestimulusispresentedrepeatedlytotheinfantuntilthereisameasurabledecline(habituation)inwhateverattendingbehaviorisbeingobserved.Atthatpointanewstimulusispresented,andanyrecovery(dishabituation)inresponsivenessisrecorded.Iftheinfantfailstodishabituateandcontinuestoshowhabituationwiththenewstimulus,itisassumedthatthebabyisunabletoperceivethenewstimulusasdifferent.Thehabituation-dishabituationparadigmhasbeenusedmostextensivelywithstudiesofauditoryandolfactoryperceptionininfants.Thesecondtechniquereliesonevokedpotentials,whichareelectricalbrainresponsesthatmayberelatedtoaparticularstimulusbecauseofwheretheyoriginate.Changesintheelectricalpatternofthebrainindicatethatthestimulusisgettingthroughtotheinfant'scentralnervoussystemandelicitingsomeformofresponse.Eachoftheprecedingtechniquesprovidestheresearcherwithevidencethattheinfantcandetectordiscriminatebetweenstimuli.Withthesesophisticatedobservationalassessmentandelectro-physiologicalmeasures,weknowthattheneonateofonlyafewdaysisfarmoreperceptivethanpreviouslyed.However,thesemeasuresareonly"indirect"indicatorsoftheinfant'sperceptualabilities.Paragraph1:Inthestudyofperceptualabilitiesofinfants,anumberoftechniquesareusedtodetermineinfants'responsestovariousstimuli.Becausetheycannotverbalizeorfilloutquestionnaires,indirecttechniquesofnaturalisticobservationareusedastheprimarymeansofdeterminingwhatinfantscansee,hear,feel,andsoforth.Eachofthesemethodscomparesaninfant'sstatepriortotheintroductionofastimuluswithitsstateduringorimmediayfollowingthestimulus.Thedifferencebetweenthetwomeasuresprovidestheresearcherwithanindicationofthelevelanddurationoftheresponsetothestimulus.Forexample,ifauniformlymovingpatternofsomesortispassedacrossthevisualfieldofaneonate(newborn),repetitivefollowingmovementsoftheeyeoccur.Theoccurrenceoftheseeyemovementsprovidesevidencethatthemovingpatternisperceivedatsomelevelbythenewborn.Similarly,changesintheinfant'sgenerallevelofmotoractivity—turningthehead,blinkingtheeyes,crying,andsoforth—havebeenusedbyresearchersasvisualindicatorsoftheinfant'sperceptualabilities.Paragraph1indicatesthatresearchersuseindirectmethodsprimarilytoobserverangeofmotoractivityinfrequencyanddurationofvariouschangeinaninfant'sstatefollowingtheintroductionofarangeofaninfant'svisualTheworduniformlyinthepassageisclosestinmeaningWhydoestheauthormentionrepetitivefollowingmovementsoftheToidentifyaresponsethatindicatesaneonate'sperceptionofaToexinwhyaneonateiscapableofrespondingtostimulionlythroughrepetitiveToarguethatmotoractivityinaneonatemayberandomandunrelatedtoToemphasizethatresponsestostimulivaryininfantsaccordingtoParagraph2:Suchtechniques,however,havelimitations.First,theobservationmaybeunreliableinthattwoormoreobserversmaynotagreethattheparticularresponseoccurred,ortowhatdegreeitoccurred.Second,responsesaredifficulttofy.Oftentherapidanddiffusemovementsoftheinfantmakeitdifficulttogetanaccuraterecordofthenumberofresponses.Thethird,andmostpotent,limitationisthatitisnotpossibletobecertainthattheinfant'sresponsewasduetothestimuluspresentedortoachangefromnostimulustoastimulus.Theinfantmayberespondingtoaspectsofthestimulusdifferentthanthoseidentifiedbytheinvestigator.Therefore,whenobservationalassessmentisusedasatechniqueforstudyinginfantperceptualabilities,caremustbetakennottoovergeneralizefromthedataortorelyononeortwostudiesasconclusiveevidenceofaparticularperceptualabilityoftheinfant.WhichofthefollowingisNOTmentionedinparagraph2asaprobleminusingthetechniqueofdirectobservation?Itisimpossibletobecertainoftheactualcauseofaninfant'sInfants'responses,whichoccurquicklyanddiffusely,areoftendifficulttoInfantsdonotrespondwelltostimulipresentedinanunnaturallaboratoryItmaybedifficultforobserverstoagreeonthepresenceorthedegreeofaThewordpotentinthepassageisclosestinmeaningWhichofthesentencesbelowbestexpressestheessentialinformationinthehighlightedsentenceinthepassage?Incorrectchoiceschangethemeaninginimportantwaysorleaveoutessentialinformation.Researchersusingobservationalassessmenttechniquesoninfantsmustnotovergeneralizeandmustbasetheirconclusionsondatafrommanystudies.Onthebasisofthedatafromoneortwostudies,itseemsthatsomeinfantsdevelopaparticularperceptualabilitynotobservedinothers.Tousedatafromoneortwostudiesoninfant'sperceptualabilities,itisnecessarytousetechniquesthatwillprovideconclusiveevidence.Whenresearchersfailtomakegeneralizationsfromtheirstudies,theirdataisoftenParagraph3:Observationalassessmenttechniqueshave emuchmoresophisticated,reducingthelimitationsjustpresented.Filmysisoftheinfant'sresponses,heartandrespirationratemonitors,andnonnutritivesuckingdevicesareusedaseffectivetoolsinunderstandinginfantperception.Filmysispermitsresearcherstocarefullystudytheinfant'sresponsesoverandoverandinslowmotion.Precisemeasurementscanbemadeofthelengthandfrequencyoftheinfant'sattentionbetweentwostimuli.Heartandrespirationmonitorsprovidetheinvestigatorwiththenumberofheartbeatsorbreathstakenwhenanewstimulusispresented.Numericalincreasesare indicatorsofheightenedinterestinthenewstimulus.Increasesnonnutritivesuckingwerefirstusedasanassessmentmeasurebyresearchersin1969.Theydevisedanapparatusthatconnectedababy'spacifiertoacountingdevice.Asstimuliwerepresented,changesintheinfant'ssuckingbehaviorwererecorded.Increasesinthenumberofsuckswereusedasanindicatoroftheinfant'sattentiontoorpreferenceforagivenvisualWhatistheauthor'sprimarypurposeinparagraphToexinwhyresearchersmustconductmorethanonetypeofstudywhentheyareattemptingtounderstandinfantperceptionTodescribenewtechniquesforobservinginfantperceptionthat eproblemsidentifiedinthepreviousparagraphTopresentandevaluatetheconclusionsofvariousstudiesoninfantTopointoutthestrengthsandweaknessesofthreenewmethodsforfyinganinfant'sreactiontostimuliThe

inthepassageisclosestinmeaningParagraph3mentionsallofthefollowingasindicationsofaninfant'sheightenedinterestinanewstimulusEXCEPTanincreaseinsuckingheartthenumberofbreathseyeParagraph4:Twoadditionaltechniquesofstudyinginfantperceptionhavecomeintovogue.Thefirstisthehabituation-dishabituationtechnique,inwhichasinglestimulusispresentedrepeatedlytotheinfantuntilthereisameasurabledecline(habituation)inwhateverattendingbehaviorisbeingobserved.Atthatpointanewstimulusispresented,andanyrecovery(dishabituation)inresponsivenessisrecorded.Iftheinfantfailstodishabituateandcontinuestoshowhabituationwiththenewstimulus,itisassumedthatthebabyisunabletoperceivethenewstimulusasdifferent.Thehabituation-dishabituationparadigmhasbeenusedmostextensivelywithstudiesofauditoryandolfactoryperceptionininfants.Thesecondtechniquereliesonevokedpotentials,whichareelectricalbrainresponsesthatmayberelatedtoaparticularstimulusbecauseofwheretheyoriginate.Changesintheelectricalpatternofthebrainindicatethatthestimulusisgettingthroughtotheinfant'scentralnervoussystemandelicitingsomeformofresponse.Accordingtoparagraph4,whichofthefollowingleadstotheconclusionthatinfantsareabletodifferentiatebetweenstimuliinahabituation-dishabituationstudy?DishabituationoccurswiththeintroductionofanewElectricalresponsesintheinfant'sbraindeclinewitheachnewHabituationiswiththeintroductionofanewTheinfantdisyslittlechangeinelectricalbrainInparagraph4,whatdoestheauthorsuggestaboutthewayaninfant'sbrainperceivesstimuli?Aninfant'spotentialtorespondtoastimulusmayberelatedtothesizeofitsChangesintheelectricalpatternsofaninfant'sbrainaredifficulttoDifferentareasofaninfant'sbrainrespondtodifferenttypesofAninfantisunabletoperceivemorethanonestimulusataParagraph5:Eachoftheprecedingtechniquesprovidestheresearcherwithevidencethattheinfantcandetectordiscriminatebetweenstimuli.Withthesesophisticatedobservationalassessmentandelectro-physiologicalmeasures,weknowthattheneonateofonlyafewdaysisfarmoreperceptivethanpreviouslyed.However,thesemeasuresareonly"indirect"indicatorsoftheinfant'sperceptualabilities.Paragraph5indicatesthatresearcherswhousedthetechniquesdescribedinthepassagediscoveredthatinfantsfinditdifficulttoperceivesometypesofneonatesofonlyafewdayscannotyetdiscriminatebetweenobservationalassessmentislessusefulforstudyinginfantperceptionthanresearcherspreviouslybelievedaneonateisabletoperceivestimulibetterthanresearchersonceParagraph3:Observationalassessmenttechniqueshave emuchmoresophisticated,reducingthelimitationsjustpresented.Filmysisoftheinfant'sresponses,heartandrespirationratemonitors,andnonnutritivesuckingdevicesareusedaseffectivetoolsinunderstandinginfantperception.■Filmysispermitsresearcherstocarefullystudytheinfant'sresponsesoverandoverandinslowmotion.■Precisemeasurementscanbemadeofthelengthandfrequencyoftheinfant'sattentionbetweentwostimuli.■Heartandrespirationmonitorsprovidetheinvestigatorwiththenumberofheartbeatsorbreathstakenwhenanewstimulusispresented.■Numericalincreasesareusedasfiableindicatorsofheightenedinterestinthenewstimulus.Increasesinnonnutritivesuckingwerefirstusedasanassessmentmeasurebyresearchersin1969.Theydevisedanapparatusthatconnectedababy'spacifiertoacountingdevice.Asstimuliwerepresented,changesintheinfant'ssuckingbehaviorwererecorded.Increasesinthenumberofsuckswereusedasanindicatoroftheinfant'sattentiontoorpreferenceforagivenvisualLookatthefoursquares[■]thatindicatewherethefollowingsentencecouldbeaddedtothepassage.Therepetitionallowsresearcherstoobservethe