雅思OG-test-2-passage-1

READINGREADINGPASSAGE1(35points)Youshouldspendabout20minutesonQuestions1-13whicharebasedonReadingPassage1below.TheFlavorofPleasureWhenitcomestocelebratingtheflavoroffood,ourmouthgetsallthecredit.Butintruth,itisthenosethatknows.Nomatterhowmuchwetalkabouttastingourfavoriteflavors,relishingthemreallydependsonacombinedinputfromoursensesthatweexperiencethroughmouth,tongueandnose.Thetaste,texture,andfeeloffoodarewhatwetendtofocuson,butmostimportantaretheslightpuffsofairaswechewourfood-whatscientistscall‘retronasalsmell’.Certainlyourmouthsandtongueshavetastebuds,whicharereceptorsforthefivebasicflavors:sweet,salty,sour,bitter,andumami,orwhatismorecommonlyreferredtoassavory.Butourtonguesareinaccurateinstrumentsasfarasflavorisconcerned.Theyevolvedtorecognizeonlyafewbasictastesinordertoquicklyidentifytoxins,whichinnatureareoftenquitebitteroracidlysour.Allthecomplexity,nuance,andpleasureofflavorcomefromthesenseofsmelloperatinginthebackofthenose.Itistherethatakindofalchemyoccurswhenwebreatheupandoutthepassingwhiffsofourchewedfood.Unlikeahound’sskullwithitsextralongnose,whichevolvedspecificallytodetectexternalsmells,ournoseshaveevolvedtodetectinternalscents.Primatesspecialiseinsavoringthemanymillionsofflavorcombinationsthattheycancreatefortheirmouths.Tastewithoutretronasalsmellisnotmuchhelpinrecognizingflavor.Smellhasbeenthemostpoorlyunderstoodofoursenses,andonlyrecentlyhasneuroscience,ledbyYaleUniversity’sGordonShepherd,beguntoshedlightonitsworkings.Shepherdhascomeupwiththeterm‘neurogastronomy’tolinkthedisciplinesoffoodscience,neurology,psychology,andanthropologywiththesavoryelementsofeating,oneofthemostenjoyedofhumanexperiences.Inmanyways,heisdiscoveringthatsmellisratherlikefacerecognition.Thevisualsystemdetectspatternsoflightanddarkand,buildingonexperience,thebraincreatesaspatialmap.Itusesthistointerprettheinterrelationshipofthepatternsanddrawconclusionsthatallowustoidentifypeopleandplaces.Inthesameway,weusepatternsandratiostodetectbothnewandfamiliarflavors.Asweeat,specializedreceptorsinthebackofthenosedetecttheairmoleculesinourmeals.Fromsignalssentbythereceptors,thebrainunderstandssmellsascomplexspatialpatterns.Usingthese,aswellasinputfromtheothersenses,itconstructstheideaofspecificflavors.Thisabilitytoappreciatespecificaromasturnsouttobecentraltothepleasurewegetfromfood,muchasourabilitytorecognizeindividualsiscentraltothepleasuresofsociallife.Theprocessissoembeddedinourbrainsthatoursenseofsmelliscriticaltoourenjoymentoflifeatlarge.Recentstudiesshowthatpeoplewholosetheabilitytosmellbecomesociallyinsecure,andtheiroveralllevelofhappinessplummets.Workingouttheroleofsmellinflavorinterestsfoodscientists,psychologists,andcooksalike.Therelativelynewdisciplineofmoleculargastronomy,especially,reliesonunderstandingthemechanicsofaromatomanipulateflavorformaximumimpact.Inthisdiscipline,chefsusetheirknowledgeofthechemicalchangesthattakeplaceduringcookingtoproduceeatingpleasuresthatgobeyondthe‘ordinary’.However,whereasmoleculargastronomyisconcernedprimarilywiththefoodor‘smell’molecules,neurogastronomyismorefocusedonthereceptormoleculesandthebrain’sspatialimagesforsmell.SmellstimuliformwhatShepherdterms‘odorobjects’,storedasmemories,andthesehaveadirectlinkwithouremotions.Thebraincreatesimagesofunfamiliarsmellsbyrelatingthemtoothermorefamiliarsmells.Gobackinhistoryandthiswaspartofoursurvivalrepertoire,likemostanimals,wedrewonoursenseofsmell,whenvisualinformationwasscarce,tosingleoutprey.Thusthebrain’sflavor-recognitionsystemisahighlycomplexperceptualmechanismthatputsallfivesensestoworkinvariouscombinations.Visualandsoundcuescontribute,suchascrunching,asdoestouch,includingthetextureandfeeloffoodonourlipsandinourmouths.Thentherearethetastereceptors,andfinally,thesmell,activatedwhenweinhale.Theengagementofouremotionscanbereadilyillustratedwhenwepicturesomeofthewide-rangingfacialexpressionsthatareelicitedbyvariousfoods-manyofthemhard-wiredintoourbrainsatbirth.Considertheresponsetothesharpnessoflemonandcomparethatwiththefacethatiswelcomingthesmoothwonderofchocolate.Theflavor-sensingsystem,everreceptivetonewcombinations,helpstokeepourbrainsactiveandflexible.Italsohasthepowertoshapeourdesiresandultimatelyourbodies.Onthehorizonwehavethepositiveapplicationofneurogastronomy:manipulatingflavortocurbourappetites.Questions1-5Questions6-9Questions10-13