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HowtheCityHurtsYourBrain,andWhatYouCanDoaboutIt1、Thecityhasalwaysbeenanengineofintellectuallife,fromthe18th-centurycoffeehousesofLondon,wherecitizensgatheredtodiscusschemistryandradicalpolitics,totheLeftBankbarsofmodernParis,wherePabloPicassoheldforthonmodernart.Withoutthemetropolis,wemightnothavehadthegreatartofShakespeareorJamesJoyce;evenEinsteinwasinspiredbycommutertrains.2、Andyet,citylifeisn’teasy.ThesameLondoncafesthatstimulatedBenFranklinalsohelpedspreadcholera;PicassoeventuallyboughtanestateinquietProvence.Whilethemoderncitymightbeahavenforplaywrights,poets,andphysicists,it’salsoadeeplyunnaturalandoverwhelmingplace.3、Nowscientistshavebeguntoexaminehowthecityaffectsthebrain,andtheresultsarechastening.Justbeinginanurbanenvironment,theyhavefound,impairsourbasicmentalprocesses.Afterspendingafewminutesonacrowdedcitystreet,thebrainislessabletoholdthingsinmemory,andsuffersfromreducedself-control.Whileit’slongbeenrecognizedthatcitylifeisexhausting–that’swhyPicassoleftParis–thisnewresearchsuggeststhatcitiesactuallydullourthinking,sometimesdramaticallyso.4、“Themindisalimitedmachine,”saysMarcBerman,apsychologistattheUniversityofMichiganandleadauthorofanewstudythatmeasuredthecognitivedeficitscausedbyashorturbanwalk.“Andwe’rebeginningtounderstandthedifferentwaysthatacitycanexceedthoselimitations.”5、Oneofthemainforcesatworkisastarklackofnature,whichissurprisinglybeneficialforthebrain.Studieshavedemonstrated,forinstance,thathospitalpatientsrecovermorequicklywhentheycanseetreesfromtheirwindows,andthatwomenlivinginpublichousingarebetterabletofocuswhentheirapartmentoverlooksagrassycourtyard.Eventhesefleetingglimpsesofnatureimprovebrainperformance,itseems,becausetheyprovideamentalbreakfromtheurbanroil.6、Thisresearcharrivesjustashumanscrossanimportantmilestone:Forthefirsttimeinhistory,themajorityofpeopleresideincities.Foraspeciesthatevolvedtoliveinsmall,primatetribesontheAfricansavannah,suchamigrationmarksadramaticshift.Insteadofinhabitingwide-openspaces,we’recrowdedintoconcretejungles,surroundedbytaxis,traffic,andmillionsofstrangers.Inrecentyears,it’sbecomeclearthatsuchunnaturalsurroundingshaveimportantimplicationsforourmentalandphysicalhealth,andcanpowerfullyalterhowwethink.7、ConsidereverythingyourbrainhastokeeptrackofasyouwalkdownbusythoroughfarelikeNewburyStreet.Therearethecrowedsidewalksfullofdistractedpedestrianswhohavetobeavoided;thehazardouscrosswalksthatrequirethebraintomonitortheflowoftraffic.(Thebrainisawarymachine,alwayslookingoutforpotentialthreats.)There’stheconfusingurbangrid,whichforcespeopletothinkcontinuallyaboutwherethey’regoingandhowtogetthere.Thereasonsuchseeminglytrivialmentaltasksleaveusdepletedisthattheyexploitoneofthecrucialweakspotsofthebrain.Acityissooverstuffedwithstimulithatweneedtoconstantlyredirectourattentionsothatwearen’tdistractedbyirrelevantthings,likeaflashingneonsignorthecellphoneconversationofanearbypassengeronthebus.Thissortofcontrolledperception-wearetellingthemindwhattopayattentionto–takesenergyandeffort.Themindislikeapowerfulsupercomputer,buttheactofpayingattentionconsumesmuchofitsprocessingpower.8、Naturalsettings,incontrast,don’trequirethesameamountofcognitiveeffort.Thisideaisknownasattentionrestorationtheory,orART,anditwasfirstdevelopedbyStephenKaplan,apsychologistattheUniversityofMichigan.Whileit’slongbeenknownthathumanattentionisascarceresource–focusinginthemorningmakesithardertofocusintheafternoon–Kaplanhypothesizedthatimmersioninnaturemighthavearestorativeeffect.ImagineawalkaroundWaldenPond,inConcord.Thewoodssurroundingthepondarefilledwithpitchpineandhickorytrees.Chickadeesandred-tailedhawksnestinthebranches;squirrelsandrabbitsskirmishintheberrybushes.Naturalsettingsarefullofobjectsthatautomaticallycaptureourattention,yetwithouttriggeringanegativeemotionalresponse–unlike,say,abackfiringcar.Thementalmachinerythatdirectsattentioncanrelaxdeeply,replenishingitself.“It’snotanaccidentthatCentralParkisinthemiddleofManhattan,”saysBerman.“Theyneededtoputaparkthere.”9、Inastudypublishedlastmonth,BermanoutfittedundergraduatesattheUniversityofMichiganwithGPSreceivers.Someofthestudentstoolastrollinanarboretum,whileotherswalkedaroundthebusystreetsofdowntownAnnArbor.Thesubjectswerethenrunthroughabatteryofpsychologicaltests.Peoplewhohadwalkedthroughthecitywereinaworsemoodandscoredsignificantlyloweronatestofattentionandworkingmemory,whichinvolvedrepeatingaseriesofnumbersbackwards.Infact,justglancingataphotographofurbanscenesledtomeasurableimpairments,atleastwhencomparedwithpicturesofnature.“Weseethepictureofthebusystreet,andweautomaticallyimaginewhatit’sliketobethere,”saysBerman.“Andthat’swhenyourabilitytopayattentionstartstosuffer.”(YukoShimizufortheBostonGlobe)Thisalsohelpsexplainwhy,accordingtoseveralstudies,childrenwithattention–deficitdisorderhavefewersymptomsinnaturalsettings.Whensurroundedbytreesandanimals,theyarelesslikelytohavebehavioralproblemsandarebetterabletofocusonaparticulartask.10、Studieshavefoundthatevenarelativelypaltrypatchofnaturecanconferbenefits.Inthelate1990s,FrancesK