TED英语演讲稿：我们在出生前学到了什么.doc

TED英语演讲稿：我们在出生前学到了什么 Mysubjecttodayislearning.Andinthatspirit,Iwanttospringonyouallapopquiz.Ready?Whendoeslearningbegin?Nowasyouponderthatquestion,maybeyourethinkingaboutthefirstdayofpreschoolorkindergarten,thefirsttimethatkidsareinaclassroomwithateacher.Ormaybeyouvecalledtomindthetoddlerphasewhenchildrenarelearninghowtowalkandtalkanduseafork.MaybeyouveencounteredtheZero-to-Threemovement,whichassertsthatthemostimportantyearsforlearningaretheearliestones.Andsoyouranswertomyquestionwouldbe:Learningbeginsatbirth. WelltodayIwanttopresenttoyouanideathatmaybesurprisingandmayevenseemimplausible,butwhichissupportedbythelatestevidencefrompsychologyandbiology.Andthatisthatsomeofthemostimportantlearningweeverdohappensbeforewereborn,whilewerestillinthewomb.NowImasciencereporter.Iwritebooksandmagazinearticles.AndImalsoamother.AndthosetworolescametogetherformeinabookthatIwrotecalledOrigins.Originsisareportfromthefrontlinesofanexcitingnewfieldcalledfetalorigins.Fetaloriginsisascientificdisciplinethatemergedjustabouttwodecadesago,anditsbasedonthetheorythatourhealthandwell-beingthroughoutourlivesiscruciallyaffectedbytheninemonthswespendinthewomb.Nowthistheorywasofmorethanjustintellectualinteresttome.IwasmyselfpregnantwhileIwasdoingtheresearchforthebook.AndoneofthemostfascinatinginsightsItookfromthisworkisthatwerealllearningabouttheworldevenbeforeweenterit. Whenweholdourbabiesforthefirsttime,wemightimaginethattheyrecleanslates,unmarkedbylife,wheninfact,theyvealreadybeenshapedbyusandbytheparticularworldwelivein.TodayIwanttosharewithyousomeoftheamazingthingsthatscientistsarediscoveringaboutwhatfetuseslearnwhiletheyrestillintheirmothersbellies. Firstofall,theylearnthesoundoftheirmothersvoices.Becausesoundsfromtheoutsideworldhavetotravelthroughthemothersabdominaltissueandthroughtheamnioticfluidthatsurroundsthefetus,thevoicesfetuseshear,startingaroundthefourthmonthofgestation,aremutedandmuffled.OneresearchersaysthattheyprobablysoundalotlikethethevoiceofCharlieBrownsteacherintheoldPeanutscartoon.Butthepregnantwomansownvoicereverberatesthroughherbody,reachingthefetusmuchmorereadily.Andbecausethefetusiswithherallthetime,ithearshervoicealot.Oncethebabysborn,itrecognizeshervoiceanditpreferslisteningtohervoiceoveranyoneelses. Howcanweknowthis?Newbornbabiescantdomuch,butonethingtheyrereallygoodatissucking.Researcherstakeadvantageofthisfactbyrigginguptworubbernipples,sothatifababysucksonone,ithearsarecordingofitsmothersvoiceonapairofheadphones,andifitsucksontheothernipple,ithearsarecordingofafemalestrangersvoice.Babiesquicklyshowtheirpreferencebychoosingthefirstone.Scientistsalsotakeadvantageofthefactthatbabieswillslowdowntheirsuckingwhensomethingintereststhemandresumetheirfastsuckingwhentheygetbored.Thisishowresearchersdiscoveredthat,afterwomenrepeatedlyreadaloudasectionofDr.SeussTheCatintheHatwhiletheywerepregnant,theirnewbornbabiesrecognizedthatpassagewhentheyhearitoutsidethewomb.Myfavoriteexperimentofthiskindistheonethatshowedthatthebabiesofwomenwhowatchedacertainsoapoperaeverydayduringpregnancyrecognizedthethemesongofthatshowoncetheywereborn.Sofetusesareevenlearningabouttheparticularlanguagethatsspokenintheworldthattheyllbeborninto. Astudypublishedlastyearfoundthatfrombirth,fromthemomentofbirth,babiescryintheaentoftheirmothersnativelanguage.FrenchbabiescryonarisingnotewhileGermanbabiesendonafallingnote,imitatingthemelodiccontoursofthoselanguages.Nowwhywouldthiskindoffetallearningbeuseful?Itmayhaveevolvedtoaidthebabyssurvival.Fromthemomentofbirth,thebabyrespondsmosttothevoiceofthepersonwhoismostlikelytocareforit-itsmother.Itevenmakesitscriessoundlikethemotherslanguage,whichmayfurtherendearthebabytothemother,andwhichmaygivethebabyaheadstartinthecriticaltaskoflearninghowtounderstandandspeakitsnativelanguage. Butitsnotjustsoundsthatfetusesarelearningaboutinutero.Itsalsotastesandsmells.Bysevenmonthsofgestation,thefetustastebudsarefullydeveloped,anditsolfactoryreceptors,whichallowittosmell,arefunctioning.Theflavorsofthefoodapregnantwomaneatsfindtheirwayintotheamnioticfluid,whichiscontinuouslyswallowedbythefetus.Babiesseemtorememberandpreferthesetastesoncetheyreoutintheworld.Inoneexperiment,agroupofpregnantwomenwasaskedtodrinkalotofcarrotjuiceduringtheirthirdtrimesterofpregnancy,whileanothergroupofpregnantwomendrankonlywater.Sixmonthslater,thewomensinfantswereofferedcerealmixedwithcarrotjuice,andtheirfacialexpressionswereobservedwhiletheyateit.Theoffspringofthecarrotjuicedrinkingwomenatemorecarrot-flavoredcereal,andfromthelooksofit,theyseemedtoenjoyitmore. AsortofFrenchversionofthisexperimentwascarriedoutinDijon,Francewhereresearchersfoundthatmotherswhoconsumedfoodanddrinkflavoredwithlicorice-flavoredaniseduringpregnancyshowedapreferenceforaniseontheirfirstdayoflife,andagain,whentheyweretestedlater,ontheirfourthdayoflife.Babieswhosemothersdidnoteataniseduringpregnancyshowedareactionthattranslatedroughlyasyuck.Whatthismeansisthatfetusesareeffectivelybeingtaughtbytheirmothersaboutwhatissafeandgoodtoeat.Fetusesarealsobeingtaughtabouttheparticularculturethattheyllbejoiningthroughoneofculturesmostpowerfulexpressions,whichisfood.Theyrebeingintroducedtothecharacteristicflavorsandspicesoftheirculturescuisineevenbeforebirth. Nowitturnsoutthatfetusesarelearningevenbiggerlessons.ButbeforeIgettothat,Iwanttoaddresssomethingthatyoumaybewonderingabout.Thenotionoffetallearningmayconjureupforyouattemptstoenrichthefetus-likeplayingMozartthroughheadphonesplacedonapregnantbelly.Butactually,thenine-month-longprocessofmoldingandshapingthatgoesoninthewombisalotmorevisceralandconsequentialthanthat.Muchofwhatapregnantwomanencountersinherdailylife-theairshebreathes,thefoodanddrinksheconsumes,thechemicalsshesexposedto,eventheemotionsshefeels-aresharedinsomefashionwithherfetus.Theymakeupamixofinfluencesasindividualandidiosyncraticasthewomanherself.Thefetusincorporatestheseofferingsintoitsownbody,makesthempartofitsfleshandblood.Andoftenitdoessomethingmore.Ittreatsthesematernalcontributionsasinformation,aswhatIliketocallbiologicalpostcardsfromtheworldoutside. SowhatafetusislearningaboutinuteroisnotMozartsMagicFlutebutanswerstoquestionsmuchmorecriticaltoitssurvival.Willitbebornintoaworldofabundanceorscarcity?Willitbesafeandprotected,orwillitfaceconstantdangersandthreats?Willitlivealong,fruitfullifeorashort,harriedone?Thepregnantwomansdietandstresslevelinparticularprovideimportantcluestoprevailingconditionslikeafingerliftedtothewind.Theresultingtuningandtweakingofafetusbrainandotherorgansarepartofwhatgiveushumansourenormousflexibility,ourabilitytothriveinahugevarietyofenvironments,fromthecountrytothecity,fromthetundratothedesert. Toconclude,Iwanttotellyoutwostoriesabouthowmothersteachtheirchildrenabouttheworldevenbeforetheyreborn.Intheautumnof1944,thedarkestdaysofWorldWarII,GermantroopsblockadedWesternHolland,turningawayallshipmentsoffood.TheopeningoftheNazissiegewasfollowedbyoneoftheharshestwintersindecades-socoldthewaterinthecanalsfrozesolid.Soonfoodbecamescarce,withmanyDutchsurvivingonjust500caloriesaday-aquarterofwhattheyconsumedbeforethewar.Asweeksofdeprivationstretchedintomonths,someresortedtoeatingtulipbulbs.BythebeginningofMay,thenationscarefullyrationedfoodreservewaspletelyexhausted.Thespecterofmassstarvationloomed.AndthenonMay5th,1945,thesiegecametoasuddenendwhenHollandwasliberatedbytheAllies. TheHungerWinter,asitcametobeknown,killedsome10,000peopleandweakenedthousandsmore.Buttherewasanotherpopulationthatwasaffected-the40,000fetusesinuteroduringthesiege.Someoftheeffectsofmalnutritionduringpregnancywereimmediatelyapparentinhigherratesofstillbirths,birthdefects,lowbirthweightsandinfantmortality.Butotherswouldntbediscoveredformanyyears.DecadesaftertheHungerWinter,researchersdocumentedthatpeoplewhosemotherswerepregnantduringthesiegehavemoreobesity,morediabetesandmoreheartdiseaseinlaterlifethanindividualswhoweregestatedundernormalconditions.Theseindividualsprenatalexperienceofstarvationseemstohavechangedtheirbodiesinmyriadways.Theyhavehigherbloodpressure,poorercholesterolprofilesandreducedglucosetolerance-aprecursorofdiabetes. Whywouldundernutritioninthewombresultindiseaselater?Oneexplanationisthatfetusesaremakingthebestofabadsituation.Whenfoodisscarce,theydivertnutrientstowardsthereallycriticalorgan,thebrain,andawayfromotherorgansliketheheartandliver.Thiskeepsthefetusaliveintheshort-term,butthebillesduelateroninlifewhenthoseotherorgans,deprivedearlyon,beemoresusceptibletodisease. Butthatmaynotbeallthatsgoingon.Itseemsthatfetusesaretakingcuesfromtheintrauterineenvironmentandtailoringtheirphysiologyaordingly.Theyrepreparingthemselvesforthekindofworldtheywillencounterontheothersideofthewomb.Thefetusadjustsitsmetabolismandotherphysiologicalprocessesinanticipationoftheenvironmentthatawaitsit.Andthebasisofthefetuspredictioniswhatitsmothereats.Themealsapregnantwomanconsumesconstituteakindofstory,afairytaleofabundanceoragrimchronicleofdeprivation.Thisstoryimpartsinformationthatthefetususestoorganizeitsbodyanditssystems-anadaptationtoprevailingcircumstancesthatfacilitatesitsfuturesurvival.Facedwithseverelylimitedresources,asmaller-sizedchildwithreducedenergyrequirementswill,infact,haveabetterchanceoflivingtoadulthood. Therealtroubleeswhenpregnantwomenare,inasense,unreliablenarrators,whenfetusesareledtoexpectaworldofscarcityandareborninsteadintoaworldofplenty.ThisiswhathappenedtothechildrenoftheDutchHungerWinter.Andtheirhigherratesofobesity,diabetesandheartdiseasearetheresult.Bodiesthatwerebuilttohangontoeverycaloriefoundthemselvesswimminginthesuperfluouscaloriesofthepost-warWesterndiet.Theworldtheyhadlearnedaboutwhileinuterowasnotthesameastheworldintowhichtheywereborn. Heresanotherstory.At8:46a.m.onSeptember11th,2019,thereweretensofthousandsofpeopleinthevicinityoftheWorldTradeCenterinNewYork-mutersspillingofftrains,waitressessettingtablesforthemorningrush,brokersalreadyworkingthephonesonWallStreet.1,700ofthesepeoplewerepregnantwomen.Whentheplanesstruckandthetowerscollapsed,manyofthesewomenexperiencedthesamehorrorsinflictedonothersurvivorsofthedisaster-theoverwhelmingchaosandconfusion,therollingcloudsofpotentiallytoxicdustanddebris,theheart-poundingfearfortheirlives. Aboutayearafter9/11,researchersexaminedagroupofwomenwhowerepregnantwhentheywereexposedtotheWorldTradeCenterattack.Inthebabiesofthosewomenwhodevelopedpost-traumaticstresssyndrome,orPTSD,followingtheirordeal,researchersdiscoveredabiologicalmarkerofsusceptibilitytoPTSD-aneffectthatwasmostpronouncedininfantswhosemother