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UsingComputationalModelingtoUnderstandLanguageAcquisition
anotherone
KI$y
Noun
Everyki.ydidn’t…
Whodoes…ispre.y?
UCComputationalSocialScience
Languageacquisition:Howhumanslearnlanguageknowledge
Languageacquisition:Howhumanslearnlanguageknowledge
Firstlanguageacquisition=Learningnativelanguage(s)
Happensasayoungchild
Languageacquisition:Howhumanslearnlanguageknowledge
Secondlanguageacquisition=Learningnon-native/foreignlanguage(s)
Happensasanolderchildoradult
Firstlanguageacquisition
Firstlanguageacquisition
Howdochildrenacquiretheknowledgeaboutlanguagethattheydofromthelanguagedatatheyhave?
Babiesareamazingatlearninglanguage
Whyfirstlanguageacquisition?
Andtheylearnalot!
Babiesareamazingatlearninglanguage
Likewhat?
Andtheylearnalot!
Likewhat?
Everythingyouknowaboutyournativelanguage(s).
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Youknowhowtoidentifywordsinfluentspeech(speechsegmentation)
Youknowhowtopronouncewords(metricalphonology)
KI$ykiTTY
whatapre$yki$y!
speechsegmentaDon
Youknowthatcertainwordsbehavelikeotherwords(syntacticcategorization)
ki$y
owl
penguin
whatapre$y___!Noun
whatapre$yki$y!
speechsegmentaDon
KI$y
kiTTY
metricalphonology
Youknowhowtointerpretwordsincontext(syntax,semantics)
“Ohlook—apre$yki$y!”“Look—there’sanotherone!”
whatapre$yki$y!
speechsegmentaDon
KI$y
kiTTY
metricalphonologyki$y
owlpenguin
Noun
syntacDccategorizaDon
Thiski.ywasboughtasapresentforsomeone.
Lilythinksthiski.yispre.y.
WhodoesLilythinktheki.yforispre.y?
Youknowhowtoputwordstogethertoaskquestions(syntax)
“Ohlook—apre$yki$y!”“Look—there’sanotherone!”
syntax,semanDcs
whatapre$yki$y!
speechsegmentaDon
KI$y
kiTTY
metricalphonologyki$y
owlpenguin
Noun
syntacDccategorizaDon
WhodoesLilythinktheki.yforispre.y?
syntax
Youknowhowtoidentifytherightinterpretationincontext(pragmatics)
“Everyki$ydidn’tsitonthestairs”
NotallkiVessatonthestairs.
NokiVessatonthestairs.x
whatapre$yki$y!
speechsegmentaDon
KI$y
kiTTY
metricalphonologyki$y
owlpenguin
Noun
syntacDccategorizaDon
“Ohlook—apre$yki$y!”“Look—there’sanotherone!”
syntax,semanDcs
pragmaDcs
“Everyki$ydidn’tsitonthestairs”
KI$y
kiTTY
metricalphonologyki$y
owlpenguin
Noun
syntacDccategorizaDon
NotallkiVessatonthestairs.
whatapre$yki$y!
speechsegmentaDon
“Ohlook—apre$yki$y!”“Look—there’sanotherone!”
syntax,semanDcs
WhodoesLilythinktheki.yforispre.y?
syntax
syntax
speechsegmentaDon
metricalphonology
syntacDccategorizaDon
syntax,semanDcs
pragmaDcs
Sohowexactlydochildrenlearnallthis?
Weknowtheydoitrelativelyquickly.
syntax
speechsegmentaDon
metricalphonology
syntacDccategorizaDon
syntax,semanDcs
pragmaDcs
Sohowexactlydochildrenlearnallthis?
Muchofthelinguisticsystemisalreadyknownbyage4.
Theyalsodon’tseemtogetalotofexplicitinstruction.Andwhentheydo,theydon’treallypayattentiontothingsthatdon’timpactmeaning.
Sohowexactlydochildrenlearnallthis?
Child:Wantotheronespoon,Daddy.Father:Youmean,youwanttheotherspoon.Child:Yes,Iwantotheronespoon,pleaseDaddy.Father:Canyousay“theotherspoon”?Child:Other…one…spoon.Father:Say“other”.Child:Other.Father:“Spoon.”Child:Spoon.Father:“Otherspoon.”Child:Other…spoon.Nowgivemeotheronespoon?
(FromMartinBraine)
Theyalsodon’tseemtogetalotofexplicitinstruction.Andwhentheydo,theydon’treallypayattentiontothingsthatdon’timpactmeaning.
Sohowexactlydochildrenlearnallthis?
Whatthey’redoing:Extractingpatternsandmakinggeneralizationsfromthesurroundingdatamostlyjustbyhearingexamplesofwhat’sallowedinthelanguage.
Wecanalsothinkaboutthisasaninformationprocessingtask.
Wecanalsothinkaboutthisasaninformationprocessingtask.
Giventheavailableinput,
Input
Lookatthatkitty!There’sanotherone.
Wheredidhehide?Whathappened?
processing&generalization
Giventheavailableinput, informationprocessingdonebyhumanminds
Input
Lookatthatkitty!There’sanotherone.
Wheredidhehide?Whathappened?
Wecanalsothinkaboutthisasaninformationprocessingtask.
Input
Lookatthatkitty!There’sanotherone.
Wheredidhehide?Whathappened?
Giventheavailableinput, informationprocessingdonebyhumanmindstobuildasystemoflinguisticknowledge
syntax
words&morphemes
metricalphonology
syntacDccategories
semanDcs
pragmaDcs
processing&generalization
Wecanalsothinkaboutthisasaninformationprocessingtask.
Giventheavailableinput,tobuildasystemoflinguisticknowledge whoseoutputweobserve
Where’sthekitty?
Thatone’sreallycute.
syntax
words&morphemes
metricalphonology
syntacDccategories
semanDcs
pragmaDcs
processing&generalization
Input
Lookatthatkitty!There’sanotherone.
Wheredidhehide?Whathappened?
informationprocessingdonebyhumanminds
Wecanalsothinkaboutthisasaninformationprocessingtask.
Tounderstandhowchildrensolvethisacquisitiontask,weneedtothinkmoreaboutallthecomponentsinvolved.
Where’sthekitty?
Thatone’sreallycute.
syntax
words&morphemes
metricalphonology
syntacDccategories
semanDcs
pragmaDcs
processing&generalization
Input
Lookatthatkitty!There’sanotherone.
Wheredidhehide?Whathappened?
AframeworkthatmakescomponentsoftheacquisiDontaskmoreexplicit
AdaptedfromLidz&Gagliardi2015
Distinguishesbetweenthingsexternaltothechildthatwecanobserve(inputsignal,child’sbehavior)vs.thingsinternaltothechild(everythingelse).
Perceptualencoding:
AdaptedfromLidz&Gagliardi2015
Turningtheinputsignalintoaninternallinguisticrepresentation=perceptualintake.
Perceptualencoding:
AdaptedfromLidz&Gagliardi2015
Involvesusingcurrentknowledgeofthelanguage(thedevelopinggrammar)…
Perceptualencoding:
AdaptedfromLidz&Gagliardi2015
Involvesusingcurrentknowledgeofthelanguage(thedevelopinggrammar)deployedinrealtimetoparsetheinput…
Perceptualencoding:
AdaptedfromLidz&Gagliardi2015
Involvesusingcurrentknowledgeofthelanguage(thedevelopinggrammar)deployedinrealtimetoparsetheinput,oftendrawingonextralinguisticsystems(likeworkingmemory,auditoryprocessing,etc.)
AdaptedfromLidz&Gagliardi2015
syllableswithstress
Perceptualencoding
Highvs.Midvs.LowrelaRvepitch
speakeridenRty
Mainvs.secondarystress
wˈʌ ɾə pɹˈɪ ɾi kˈɪ ɾiMs s
L L H H M M
(Mom)
AdaptedfromLidz&Gagliardi2015
GeneratingobservablebehaviorInvolvesthecurrentlinguisticrepresentationsandthedevelopinggrammarbeingusedbytheproductionsystem.
AdaptedfromLidz&Gagliardi2015
GeneratingobservablebehaviorTheseareusedinrealtimetogeneratelinguisticbehavior(utterances)andnon-linguisticbehavior(pointing,looking,etc.).Thesebehaviorsrequirelinguisticsystems(utterancegeneration)andextralinguisticsystems(motorcontrol,attention,decision-making,etc.)
AdaptedfromLidz&Gagliardi2015
Inference=learning
Thisishowchildrenlearnfromthecurrentdatainordertoupdatethedevelopinggrammar.
AdaptedfromLidz&Gagliardi2015
Inference=learning
Constraintsonchildren’shypothesesandfiltersontheirattentioncausethemtoheedasubsetoftheperceptualintake—thisistheacquisitionalintake.
AdaptedfromLidz&Gagliardi2015
syllableswithstress
Highvs.Midvs.LowrelaRvepitch
speakeridenRty
Mainvs.secondarystress
wˈʌ ɾə pɹˈɪ ɾi kˈɪ ɾiMs s
L L H H M M
(Mom)wˈʌ ɾə pɹˈɪ ɾi kˈɪ ɾi
syllableswithstress
perceptualintake
acquisiDonalintake
AdaptedfromLidz&Gagliardi2015
Inference=learning
Inferencehappensovertheacquisitionalintake,usingextralinguisticabilities(statisticallearning,probabilisticinference,hypothesistesting,etc.)…
AdaptedfromLidz&Gagliardi2015
Inference=learningInferencehappensovertheacquisitionalintake,usingextralinguisticabilities(statisticallearning,probabilisticinference,hypothesistesting,etc.)togeneratethemostup-to-dateideasaboutthelanguage’sgrammar.
AdaptedfromLidz&Gagliardi2015
Thiswholeprocesshappensoverandoveragainthroughoutthelearningperiod
AdaptedfromLidz&Gagliardi2015
Aninformativecomputationalmodeloflanguageacquisitioncapturestheseimportantpiecesinanempirically-groundedway.
Theoretical
Corpus
Experimental
AdaptedfromLidz&Gagliardi2015
Whenwehaveaninformativecomputationalmodel,itwillconnectthechild’sinputtothechild’soutputinjustthisway.
External ✔
AdaptedfromLidz&Gagliardi2015
Wecanthenlook“underthehood”toseewhatinternalpiecesmadethatpossible—thispartishardtodoinrealchildren’sminds!
Internal
✔
✔
AdaptedfromLidz&Gagliardi2015
Upshot:Withcomputationalmodeling,wecanunderstandmorepreciselyhowthelearningstrategiesthatchildrenusework.
✔✔
speechsegmentaDon
Somethingswe’velearnedbymodel-buildingthisway
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
speechsegmentaDonSomethingswe’velearned
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
InvesDgaDngaBayesianinferencestrategyfortheveryearlystagesofspeechsegmentaDonoccurringaroundsixmonths
speechsegmentaDonSomethingswe’velearned
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
TheintuiDonofBayesianinference(appliedtospeechsegmentaDon)
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
Thebestanswer(basedontheu$eranceyoujustheard)…
speechsegmentaDonSomethingswe’velearned
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
Thebestanswer(basedontheu$eranceyoujustheard)dependsonyourpriorbeliefsaboutwhatgoodanswerslooklike…
TheintuiDonofBayesianinference(appliedtospeechsegmentaDon)
speechsegmentaDonSomethingswe’velearned
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
Thebestanswer(basedontheu$eranceyoujustheard)dependsonyourpriorbeliefsaboutwhatgoodanswerslooklikeandhoweasilyananswerexplainsthedataobservedintheu$erance.
TheintuiDonofBayesianinference(appliedtospeechsegmentaDon)
speechsegmentaDon
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
Mathemahcallyencodedpreferences: wʌɾə pɹɪɾi kɪɾi
wʌ ɾə pɹɪɾikɪɾi
wʌɾə pɹɪɾikɪɾi
Bayesianinference
Somethingswe’velearned
Strategy:IdenDfyalistofwordforms(=lexicon)thatbestgeneratestheobservablefluentspeechuXerances
speechsegmentaDon
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
wʌɾə pɹɪɾi kɪɾi
wʌ ɾə pɹɪɾikɪɾi
wʌɾə pɹɪɾikɪɾiMathemahcallyencodedpreferences:
(1)Prefershorterwords
Bayesianinference
Somethingswe’velearned
Strategy:IdenDfyalistofwordforms(=lexicon)thatbestgeneratestheobservablefluentspeechuXerances
speechsegmentaDon
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
wʌɾə pɹɪɾi kɪɾi
wʌ ɾə pɹɪɾikɪɾi
wʌɾə pɹɪɾikɪɾi
Mathemahcallyencodedpreferences:
(1)Prefershorterwords
(2)Preferlexiconswithfewerwords
Bayesianinference
Somethingswe’velearned
Strategy:IdenDfyalistofwordforms(=lexicon)thatbestgeneratestheobservablefluentspeechuXerances
speechsegmentaDon
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
wʌɾə pɹɪɾi kɪɾi
wʌ ɾə pɹɪɾikɪɾi
wʌɾə pɹɪɾikɪɾi
Mathemahcallyencodedpreferences:
(1)Prefershorterwords
(2)Preferlexiconswithfewerwords
FindthebestsegmentaDon
Bayesianinference
Somethingswe’velearned
Strategy:IdenDfyalistofwordforms(=lexicon)thatbestgeneratestheobservablefluentspeechuXerances
speechsegmentaDon
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
wʌɾə pɹɪɾi kɪɾi
wʌ ɾə pɹɪɾikɪɾi
wʌɾə pɹɪɾikɪɾi
Mathemahcallyencodedpreferences:
(1)Prefershorterwords
(2)Preferlexiconswithfewerwords
Bayesianinference
FindthebestsegmentaDonthatbalancesthesepreferences
Somethingswe’velearned
Strategy:IdenDfyalistofwordforms(=lexicon)thatbestgeneratestheobservablefluentspeechuXerances
speechsegmentaDon
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
wʌɾə pɹɪɾi kɪɾi
wʌ ɾə pɹɪɾikɪɾi
wʌɾə pɹɪɾikɪɾi
Mathemahcallyencodedpreferences:
(1)Prefershorterwords
(2)Preferlexiconswithfewerwords
FindthebestsegmentaDonthatbalancesthesepreferences
andcangeneratetheobservablefluentspeechuXerances
Bayesianinference
Somethingswe’velearned
Strategy:IdenDfyalistofwordforms(=lexicon)thatbestgeneratestheobservablefluentspeechuXerances
speechsegmentaDon
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
Isitusefulforchildren?✓ModeledlearnerswithoutcognitivelimitationsontheirinferenceandmemorycanusethisstrategytosegmentfairlywellwhengivenrealisticEnglishchild-directedspeechdatatolearnfrom.
Bayesianinference
Theinferredlexicons,whilenotperfect,areveryusefulforsubsequentstagesoflanguageacquisition.
Somethingswe’velearned
speechsegmentaDon
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
Isituseful?✓
✓
ModeledlearnerswithcognitivelimitationsontheirinferenceandmemorycanstillusethisstrategyandsegmentEnglishquitewell.
Isituseablebychildren?
Bayesianinference
Somethingswe’velearned
speechsegmentaDon
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
Isituseful?✓ Isituseable?✓
Doesitworkfordifferentlanguages?
Itsegmentswellforlanguageswithdifferentmorphologyandsyllableproperties:Spanish,Italian,German,Hungarian,Japanese,Farsi
✓
Bayesianinference
Somethingswe’velearned
speechsegmentaDon
whatapre$yki$y!
= wʌɾəpɹɪɾikɪɾi wʌɾ ə pɹɪɾi kɪɾi
Phillips&Pearl2012,2014a,2014b,2015a,2015b,Pearl&Phillipsinpress
Isituseful?✓ Isituseable?✓ Doesitworkfordifferentlanguages?✓
Bayesianinference
BayesianinferenceseemstobeagoodproposalforaveryearlyspeechsegmentaDonstrategy.
Somethingswe’velearned
Recap
Languageacquisihonisanintereshngareaofresearchinhumancognihonbecauseit’sreallyhardandliXlehumansarereallygoodatit.
syntax
speechsegmentaDon
metricalphonology
syntacDccategorizaDon
syntax,semanDcs
pragmaDcs
RecapLanguageacquisihon
isintereshng
Tounderstandhowitworks,wecanbuildcognihvecomputahonalmodelsthatcapturetheimportantcomponentsoftheprocessandthenlookinsidetoseeexactlyhowtheywork
AdaptedfromLidz&
RecapLanguageacquisihon
isintereshng
Adaptedfrom
Modelscancaptureimportantcomponentsand
wecanlookinside
SomerecentfindingswiththisapproachsuggestBayesianinferenceisaplausibleearlyspeechsegmentahonstrategythat’suseful,useable,
andworksformanylanguages
Thankyou!
anotherone
KI$y
Noun
Everyki.ydidn’t…
Whodoes…ispre.y?
UCComputationalSocialScience
