睡眠之谜

　　NOVA:MysteriesofSleepLikevirtuallyeveryotheranimal,humansneedsleeptosurvive.Butwhy?Whatdowegainfromspendingnearlyathirdofourlivesinsuchadefenselessstate?Andwhat'satstakeifwesleeppoorly?Thefunctionsofsleephavelongbeensomethingofamystery.Butnowscientistsarepeeringdeepintothebraintoseewhathappenswhilewesnooze.Onestudyrevealsthatwell-timedburstsofpinknoisecannudgeaperson'sbrainwaves,extendingperiodsofslow-wave,ordeep,sleep.Andtoddlerslearningnewwordsshowthattakingevenashortnapafterlearningsomethingnewcanhelptheinformationstick.Andwhenitcomestosleepingpoorly,itmayturnoutthathavinginterruptedsleepcanbejustasharmfulasmissingsleepaltogether.Asscientistscometounderstandthepowerfulrolethatsleep--orlackofit--playsineverythingfrommemorytotraumatoemotionregulation,onethingisclear:Thisbiologicalfunctionisascrucialasitiscomplex.