The-Language-Acquisition-Device-(

1、TheLanguageAcquisitionDevice(LAD)isapostulatedorganofthebrainthatissupposedtofunctionasacongenitaldeviceforlearningsymboliclanguage(i.e.,languageacquisition).FirstproposedbyNoamChomsky,theLADconceptisaninstinctivementalcapacitywhichenablesaninfanttoacquireandproducelanguage.Itiscomponentofthenativisttheoryoflanguage.Thistheoryassertsthathumansarebornwiththeinstinctorinnatefacilityforacquiringlanguage.ChomskyhasgraduallyabandonedtheLADinfavourofaparameter-settingmodeloflanguageacquisition(princi。

2、plesandparameters).ChomskymotivatedtheLADhypothesisbywhatheperceivedasintractablecomplexityoflanguageacquisition,citingthenotionofinfiniteuseoffinitemeansproposedbyWilhelmvonHumboldt.Atthetimeitwasconceived(1957–1965),theLADconceptwasinstrictcontrasttoB.F.Skinner'sbehavioralpsychologywhichemphasizedprinciplesoflearningtheorysuchasclassicalandoperantconditioningandimitationoverbiologicalpredisposition.TheinteractionisttheoryofJeromeBrunerandJeanPiagetlateremphasizedtheimportanceoftheinteractionbe。

3、tweenbiologicalandsocial(natureandnurture)aspectsoflanguageacquisition.Differingfromthebehavioristswhoemphasizetheimportanceofsocialinteractionsinlanguageacquisition,Chomsky(1965)setoutaninnatelanguageschemawhichprovidesthebasisforthechild’sacquisitionofalanguage.Theacquisitionprocesstakesplaceinaninfantsmindbecauseofthismentalorganwhichenableshim/hertospeakdespitethelimitednatureofthePrimaryLinguisticData(PLD,theinputsignalsreceived)andthedegeneratenature(frequentincorrectusage,utterancesofpart。

4、ialsentences)ofthatdata.Giventhispovertyofthestimulus,alanguageacquisitionmodelrequiresanumberofcomponents.Firstly,thechildmusthaveatechniqueforrepresentinginputsignalsand,secondly,awayofrepresentingstructuralinformationaboutthem.Thirdly,theremustbesomeinitialdelimitationoftheclassofpossiblelanguagestructurehypotheses.Fourthly,thechildrequiresamethodfordeterminingwhateachofthesehypothesesimplieswithrespecttoeachsentence.Finally,anadditionalmethodisneededbywhichthechildcanselectwhichhypothesisisc。

5、ompatiblewiththePLD.Equippedwiththisendowment,firstlanguagelearningisexplainedasperformedbyaLanguageAcquisitionDeviceprogressingthroughthefollowingstages:ThedevicesearchestheclassoflanguagestructurehypothesesandselectsthosecompatiblewithinputsignalsandstructuralinformationdrawnfromthePLD.Thedevicethenteststhecompatibilityusingtheknowledgeofimplicationsofeachhypothesisforthesentences.Onehypothesisor‘grammar’isselectedasbeingcompatiblewiththePLD.Thisgrammarprovidesthedevicewithamethodofinterpr。

6、etingsentences(byvirtueofitscapacityforinternallyrepresentingstructuralinformationandapplyingthegrammartosentences).ThroughthisprocessthedeviceconstructsatheoryofthelanguageofwhichthePLDareasample.Chomskyarguesthatinthisway,thechildcomestoknowagreatdealmorethanshehas‘learned’,acquiringaknowledgeoflanguage,whichgoesfarbeyondthepresentedprimarylinguisticdataandisinnosensean'inductivegeneralization'fromthesedata.Insomeviewsoflanguageacquisition,theLADisthoughttobecomeunavailableafteracertainage—the。

7、criticalperiodhypothesis(i.e.,issubjecttomaturationalconstraints).FeralchildrencasessuchasGenieprovidekeyexamplesfortheLADaspectofthenativisttheoryandthatitbecomesunavailableafteracertainage.TheLanguageAcquisitionDevice(LAD)isahypotheticalbrainmechanismthatNoamChomskypostulatedtoexplainhumanacquisitionofthesyntacticstructureoflanguage.Thismechanismendowschildrenwiththecapacitytoderivethesyntacticstructureandrulesoftheirnativelanguagerapidlyandaccuratelyfromtheimpoverishedinputprovidedbyadultlang。

8、uageusers.Thedeviceiscomprisedofafinitesetofdimensionsalongwhichlanguagesvary,whicharesetatdifferentlevelsfordifferentlanguagesonthebasisoflanguageexposure.TheLADreflectsChomsky'sunderlyingassumptionthatmanyaspectsoflanguageareuniversal(commontoalllanguagesandcultures)andconstrainedbyinnatecoreknowledgeaboutlanguagecalledUniversalGrammar.ThistheoreticalaccountofsyntaxacquisitioncontrastssharplywiththeviewsofB.F.Skinner,JeanPiaget,andothercognitiveandsocial-learningtheoristswhoemphasizetheroleofe。

9、xperienceandgeneralknowledgeandabilitiesinlanguageacquisition.Seealso:LANGUAGEDEVELOPMENTBibliographyChomsky,Noam.AspectsoftheTheoryofSyntax.Cambridge,MA:MITPress,1965.LauraL.NamyReadmore:LanguageAcquisitionDevice-Chomsky,Languages,Syntax,Aspects,Lad,andSet。