lecture 4 - university of california, irvinelpearl/courses/... · lecture 4 biological bases of...
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Ling51/Psych56L:AcquisitionofLanguage
Lecture4BiologicalbasesoflanguageacquisitionII
Announcements
Reviewquestionsforbiologicalbasesoflanguageacquisitionavailable
BeworkingonHW2(due10/13/16)–rememberthatcollaborationishighlyencouraged
Thecriticalperiodhypothesis
Critical&sensitiveperiods
“criticalperiodforlanguage”=biologicallydeterminedperiodduringwhichlanguageacquisitionmustoccurinorderforlanguagetobelearnedfullyandcorrectly
Otherbiologicallydetermineddeadlines: -imprinting:chicks&ducklingsfollowfirstthingtheyseeforever(it’s
likelytheirmommy) -visualcellsinhumans:ifcellsforbotheyesdon’treceivevisualinput
duringthefirstyearorsooflife,theylosetheabilitytorespondtovisualinput
Critical&sensitiveperiods
“sensitiveperiod”:biologicallydeterminedperiodduringwhichlearningmustoccurfordevelopmenttohappencorrectly,butdevelopmentcanstilloccurpartiallyafterthisperiod
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
(1)Idealexperiment:deprivechildrenofalllinguisticinputduringthepurportedcritical/sensitiveperiodandseehowlanguagedevelopmentoccurs.
Problem:idealexperimentisn’tsoidealethicallyorlogistically
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Somehistoricalandmoderncasesthathaveunintentionallyprovidedlackoflinguisticinputtochildren:
“wildchildren”:likeVictorofAveyron,OxanaMalayaoftheUkraine
Problem:unclearlackoflanguageissolelyduetolackoflinguisticinput(maybeotherfactors)
http://www.radiolab.org/story/293679-forbidden-experiment/
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Onesuccessstoryforlackoflinguisticinputwithayoungchild:Isabelle
1930s:6-year-oldIsabellediscoveredhiddenawayinadarkroomwithadeaf-mutemotherasheronlycontact.
Shewastaughttospeakandbyage8,appearedtobenormal.Potentialimplication:Isabellediscoveredbeforecritical/sensitiveperiodwasover.
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Amorethoroughstudy:Genie
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Amorethoroughstudy:Genie
1970s:13-year-oldGeniebroughtbyhermothertosocialservicesafterescapingmentallyillfather;untilmother’sescape,hadnolanguageinput(andveryhorrificlivingconditions)
Byage17,shehadafive-year-old’svocabulary,andcouldexpressmeaningsbycombiningwordstogether.
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Amorethoroughstudy:Genie
However…syntacticskillslaggedfarbehind-deficientinbothproductionandcomprehension.
“Mamawashhairinsink.” “Likegorideyellowschoolbus.”“Atschoolscratchface.” “Fathertakepiecewood.Hit.Cry.”“IwantCurtissplaypiano.” “Applesaucebuystore”“Manmotorcyclehave.” “FatherhitGeniecrylongtimeago.”
Dichoticlisteningtasksshowedlanguagewasaright-hemisphereactivityforher(whileit’saleft-hemisphereactivityformostadults).
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Amorethoroughstudy:Genie
PotentialImplication:Geniediscoveredaftercriticalperiodwasover.
However,Geniemayhavehadothercognitivedisabilities…
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Lenneberg(1967):“theonlysafeconclusionstobedrawnfromthemultitudeofreportsislifeindarkclosets,wolves’dens,forests,orsadisticparents’backyardsisnotconducivetogoodhealthornormaldevelopment”
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Anotherstudy:Chelsea(Curtiss1988)
Familybackground:Apartiallydeafwomanincorrectlydiagnosedas“retarded”.Fromalovinghome.
Discoveredatage31,andfittedwithhearingaids
Outcome:Learnedalargevocabulary,butsyntaxandmorphologyworsethanGenie.
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Anotherstudy:Chelsea(Curtiss1988)
SamplespeechfromChelsea:
(1) Thesmallathehat
(2)OrangeTimcarin
(3)IWandabedrivecome
(4)Breakfasteatinggirl
(5)TheyareiscarintheTim
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
(2)Lateacquisitionofsignlanguage(ASL):deaf-of-hearingchildrenwhoseparentsdon’tknowsignlanguage.Childrenareeventuallyexposedtosignlanguagewhentheyencounterotherdeafchildren.
Good:individualshavenormalearlychildhoodexperience,exceptforlackoflanguageinput
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Ifacriticalorsensitiveperiodistrue,childrenwholearnearliershouldbebetterthanchildrenwholearnedlater…
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Ifacriticalorsensitiveperiodistrue,childrenwholearnearliershouldbebetterthanchildrenwholearnedlater-thisiswhatNewport(1990)found.Childrenwhowere4to6yearsoldwhenfirstexposedtoASLwerefarsuperiorintheirsignlanguageabilitywhencomparedtochildrenwhowereexposedafterage12.
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Alsoimportant:notjustabouthowlongsignlanguagespeakershadknownthelanguage.Speakerswhohadbeensigningformorethan30yearsshowedthissamedifference:thoseexposedyoungerwerefarsuperiorintheirlanguageskillstothoseexposedwhentheywereolder.
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
(3)Lookatsecondlanguagelearning. Why?Childrenwholearnasecondlanguagewhentheyareyoung
oftenbecomeindistinguishablefromtheirnative-bornpeers.Incontrast,peoplewhoareolderhaveverydifferentoutcomes.
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Testingagedifferencesinsecondlanguageacquisition:
-Oyama(1976):testingItalianimmigrantslearningEnglishAgeofarrivalwasbetterpredictorofaccentthanhowmanyyearstheimmigranthadbeenspeakingEnglish
-Oyama(1978):Ageofarrivalwasbetterpredictorofcomprehensionthannumberofyearsspeakingthelanguage(notjustaboutmotorskilllearningability)
Critical&sensitiveperiods
Howdowetestforacritical/sensitiveperiodforlanguageacquisition?
Testingagedifferencesinsecondlanguageacquisition:
Johnson&Newport(1989):testinggrammaticalcompetencyofChinese&KoreannativeslivingintheUS
Heardrecordedvoicesspeakingsentences,andhadtojudgewhethertheywerecorrectornot. “Thefarmerboughttwopigatthemarket.” “Tomisreadingbookinbathtub.”
Second-languageproficiencydependentonageofinitiallanguageexposure(evenwithsamenumberofyearsofexposuretotal)
Morphology:e.g.verbagreementinproduction
(birthon) (4-6yrson) (12yrson)
AgeofInitialLanguageExposure
Tomis/*arereadingbookinbathtub
Second-languageproficiencydependentonageofinitiallanguageexposure(evenwithsamenumberofyearsofexposuretotal)
Age of initial exposurebirthon (4-6yrson) (12yrson)
Second-languageproficiencydependentonageofinitiallanguageexposure–butnotallaspectsaredependent
Basicwordorder:SVO
SubjectVerbObject
Ex:“Penguinslikefish.”
Asopposedto
“Fishpenguinslike”(ObjectSubjectVerb)
Second-languageproficiencydependentonageofinitiallanguageexposure–butnotallaspectsaredependent
Balari&Lorenzo2015:Phonologyandcertainaspectsofmorphosyntax(howwordsandwordpiecescombinetogethertoformphrases)seemtobesetearlierwhilelexicalknowledgeseemstoremainattainableforquitesometime.
AfterMaturationNorelationshipbetweenAgeofArrivalandTestScore
DuringMaturationDeclineinabilitywithmaturation.
Beforeandafterthecritical/sensitiveperiod(sometimescalled“maturation”)
Someevidenceforcritical/sensitiveperiod
Johnson&Newport(1989)alsofoundthatperformancewasnotcorrelatedwith:
■ FormalinstructioninEnglish■ AmountofinitialexposuretoEnglish■ ReportedmotivationtolearnEnglish■ Self-consciousnessinEnglish■ IdentificationwithAmericanculture
Functionalmagneticresonanceimaging(fMRI)studiesconfirmdifferentneuralprocessingforlanguageinindividualswholearnedbeforeage7to8vs.individualswholearnedafterthisage(Kimetal.1997,Dehaeneetal.1997,Wartenburgeretal.2003,Sauretal.2009)
Someevidenceforcritical/sensitiveperiod
Event-relatedpotential(ERP)studiesconfirmdifferingleft-hemispherespecializationforlanguageinindividualswholearnedbeforeage4vs.individualswholearnedbetween4and7vs.individualswholearnedafter7(Weber-Fox&Neville1996,1999,Isel2005)
Someevidenceforcritical/sensitiveperiod Sumup:Critical/sensitiveperiod
■ Languagelearningiscomparativelyeffortlessbeforeage8orso,extremelyeffortfulafter
■ Appliestobothfirstandsecondlanguagelearning■ Appliestospokenandsignedlanguages■ Critical/sensitiveperiodssimilartootherbiologically-
programmedabilitiesinhumansandotherspecies
Sumup:Critical/sensitiveperiod
http://www.quickmeme.com/meme/36f39x/
Criticalvs.sensitive,revisited
Ifthereistrulyacriticalperiodoflanguageacquisition,peoplelearninglanguageafterthisperiodshouldnotsucceedverywellatall(theyshouldbeequallybad).Incontrast,peoplewithinthecriticalperiodshoulddoverywell(theyshouldbeequallynative-like).
Expectation:discontinuousfunctionofperformance
languageacquisitionperformance
age
criticalperiod
However,mostoftheevidencewe’veseen(includingtheonebelow)suggeststhatthereisasmootherdrop-off.(supportforsensitiveperiod)
Hakuta,Bialystok,&Wiley2003
Criticalvs.sensitive,revisitedSeeThiessen,Girard,&Erickson2016forasummaryofstudiessupportingasensitiveinsteadofacriticalperiod.
Criticalvs.sensitive,revisited
“Fromthisperspective,developmentalchangearises,notfromaswitchfromonesetofprocessestoanother,butduetochangesintheeffectivenessofacontinuouslypresentsetoflearningprocesses…whilethe[statisticallearning]processesofextractionandintegrationareactiveacrossthelifespan,theiroutcomewilldifferasafunctionofthelearner’spriorexperienceandmaturationalstate.”
Thepotentialrelationshiptodomain-generalstatisticallearningprocesses:
SeeThiessen,Girard,&Erickson2016forasummaryofstudiessupportingasensitiveinsteadofacriticalperiod.
Criticalvs.sensitive,revisited
Thepotentialrelationshiptodomain-generalstatisticallearningprocesses:“…therearetwomajorfactorsthatmayplausiblybelinkedtochangesinlanguagelearningoutcomesassociatedwithincreasingage.Thefirstisincreasingfamiliarityoflanguage,whichmakesalearnerbeperadaptedtothelanguageswithwhichtheyarefamiliar,butlessabletoadapttonovellanguages.Thesecondfactorismaturaqonalchanges,whichalterboththecogniqvearchitecturesupporqngstaqsqcallearning,andthedegreeofplasqcitywithwhichthelearner’sneurobiologicalorganizaqoncanadapttonovelinput.”
SeeThiessen,Girard,&Erickson2016forasummaryofstudiessupportingasensitiveinsteadofacriticalperiod.
Criticalvs.sensitive,revisited
Whythere’sanageeffect:
“…theadvantageofyoungerlanguagelearnersrelates,inpart,tothefactthatinfantsandyoungchildrenarehighlyadaptablelearners,butnotyetstronglyadaptedtotheirparqcularlinguisqcenvironment.”
Sincewedon’toftenseethissharpdrop-offinperformance,it’smorelikelythereisasensitiveperiodforlearningaspectsoflanguage,ratherthanacriticalperiod.
languageacquisitionperformance
age
criticalperiod
sensitiveperiod
Criticalvs.sensitive,revisited
“…ratherthanpostulatingonecriticalperiodforlanguageacquisition,amoreplausiblehypothesisisthatgrammaticaldevelopmentischaracterizedbyseveralsensitivephases…aphasecanbecharacterizedbyanoptimalperiodfortheacquisitionofthephenomenoninquestion…characterizedbyarelativelyshortonset,followedbyanextendedoptimalperiodandagradualoffset…”–Meisel,2013
Criticalvs.sensitive,revisited
Sowhyareyoungerchildrenbetter?
“Lessismore”hypothesis:Newport1991
Childrencanrememberlessthanadults(andhaveothercognitivelimitations,likelessattention).Perhapslanguageisactuallyeasiertofigureoutiftheinputislimitedtosmallerchunks.Adultsremembermoreandcanstorelongerchunks,whichmakestheiranalyticaltaskharder.
Studiessupportingtheideathatalimitationonthewaychildrenprocessinputleadstobetterlearningperformance:Phillips&Pearl2012,Phillips&Pearlinpress,Pearl,Goldwater,&Steyvers2011,Pearl,Goldwater,&Steyvers2010,Pearl2009,Pearl&Lidz2009,Pearl2008,Pearl&Weinberg2007,Dresher1999,Lightfoot1999,Lightfoot1991
Someexperimentalsupportfortheutilityof“Lessismore”whenlearningaforeignlanguageasanadult:Chin&Kersten2010
AdultslearningFrenchovertwoone-hoursessions-fullsentencesvs.smallphrasesthatincrementallyincreasedlengthtofullsentences(tosimulatechildren’ssteadilyexpandingprocessingabilities)
Adultslearningincrementallyoutperformedadultslearningfromfullsentencesonlanguageproficiencytestsofvocabularyandgrammar.
Sowhyareyoungerchildrenbetter?
Sowhyareyoungerchildrenbetter?
Someexperimentalsupportfortheutilityof“Lessismore”whenlearningalanguageasanadult:Finnetal.2014
Adultsubjectslistenedtoanartificiallanguagetheyweremeanttolearn.Onegroupwastoldtopaycloseattention(activelisteners)whiletheothergrouplistenedmorepassively—theyweredistractedbydoingapuzzleorcoloringwhiletheylistened.
Thepassivelistenersoutdidtheactivelistenerswhenitcametolearningmorphology(howwordscombinetogether)!
Activelisteners:Morecognitiveresourcesfocusedontask.Passivelisteners:Fewercognitiveresourcesfocusedontask.
Sowhyareyoungerchildrenbetter?
Someexperimentalsupportfortheutilityof“Lessismore”whenlearningalanguageasanadult:Finnetal.2014
"Wefoundthatefforthelpsyouinmostsituaqons,forthingslikefiguringoutwhattheunitsoflanguagethatyouneedtoknoware,andbasicorderingofelements.Butwhentryingtolearnmorphology,atleastinthisarqficiallanguagewecreated,it'sactuallyworsewhenyoutry.”—AmyFinn
http://www.sciencedaily.com/releases/2014/07/140721142211.htm
Recap
Thereappearstobeaperiodduringwhichlanguageisacquiredmosteasily-whetherthisisacriticalperiodorsensitiveperiodmayvarydependingonwhatspecificlinguisticknowledgewelookat.
The“lessismore”hypothesisisoneideaforwhychildren’smindsmightbemoresuitedtolanguagelearningthanadults’minds.
Questions?
Youshouldbeabletoanswerupthroughquestion19ofthebiobasesreviewsheet,andupthrough
question19onHW2.