阅读理解Asthehumanbrainevolvedhumanswereabletolaughbeforetheycouldspeakaccordingtoanewstudy．Buthere’sthepunchline：Laughterandjoyarenotuniquetohumansthestudys

　　阅读理解

　　Asthehumanbrainevolvedhumanswereabletolaughbeforetheycouldspeakaccordingtoanewstudy．Buthere’sthepunchline：Laughterandjoyarenotuniquetohumansthestudysays．Ancestralformsofplayandlaughterexistedinotheranimalslongbeforehumansbeganlaughing．

　　“Humanlaughterhasitsrootsinouranimationpast”saidJaakPankseppaprofessorofpsychobiologyatBowlingGreenStateUniversityinOhio．Panksepphasstudiedratsandfoundthatwhenthey“play”theyoftenchirp(唧唧叫)－anearly－stageformoflaughteraccordingtothescientist．InanarticletobepublishedtomorrowinthejournalSciencehemakestheargumentthatanimallaughteristhebasisforhumanjoy．

　　Instudyinglaughterscientistshavefocusedmostlyonrelatedissues－humorpersonalityhealthbenefitssocialtheory－ratherthanlaughteritself．Newresearchhowevershowsthat“circuits”(电路)forlaughterexistinveryancientregionsofthehumanbrain．Ashumanshaveincludedlanguageintoplaywemayhavedevelopednewconnectionstojoyouspartsofourbrainsthatevolvedbeforethecerebralcortex(大脑皮层)theouterlayerassociatedwiththoughtandmemory．

　　Thereisplentyofevidencethatmanyothermammalsmakeplaysoundswhicharelikehumanlaughter．Indeedanimalsarecapableofmanyemotionalfeelingsjustlikehumanssomescientistssay．"Therecognitionbyneuroscientists(神经系统科学家)thatthebrainsystemsforpainpleasureandfeararethesameinhumansandothermammalsunderlineoursimilaritytootherspeciesandisextremelyimportant"saidTecumsehFitchapsychologylecturerattheUniversityofSt．AndrewsinScotland．Ina2003studyPankseppandBowlingGreenStateUniversityneurobiologistJeffBurgdorfshowedthatifratsaretickled(呵痒)inaplayfulwaytheyreadilychirp．Ratsthatweretickleddevelopedarelationshipwiththeresearchersandbecamerapidlyconditionedtoseektickles．Understandingthechirpingoftheratsmayhelpscientistsbetterunderstandhumanlaughter．

　　RobertProvineapsychologyprofessorattheUniversity