Manyofusbelievethataperson’smindbecomeslessactiveashegrowsolder．Butthisisnottrue，accordingtoDr．LissyF．Jarvik，professorofpsychiatry(精神病学)attheUniversityofCalifornia，LosAngeles，andaboardmemberoftheNewCenterforAgingattheVeteransHospital．Shehasstudiedthementalfunctioningofagingpersonsforseveralyears.Forexample，oneofherstudiesconcerns136pairsoftwins,whowerefirstexaminedwhentheywerealready60yearsold．AsDr．Jarvikcontinuedthestudyofthetwinsintotheir70sand80s，theirmindsdidnotgenerallydecline(下降)aswasexpected．
However，therewassomedeclineintheirpsycho-motor(精神运动的)speed．Thismeansthatittookthemlongertoaccomplishmentaltasksthanitusedto．Butwhenspeedwasnotafactor，theylostverylittleintellectual(智力的)abilityovertheyears.Ingeneral，Dr．Jarvik’sstudieshaveshownthatthereisnodeclineinknowledgeorreasoningability．Thisistruenotonlyintothe30sand40s，butintothe60sand70saswell．
Asforlearningnewthings，andabilitytoremember，studiesbyDr．Jarvikandothersshowthattheoldareequaltotheyoung．Itistruethatolderpeoplethemselvesoftencomplainthattheirmemoryisnotasgoodasitoncewas．However，muchof whatwecall“lossofmemory”isnotthatata11．
Inthecaseswheretheolderperson’smindreallyseemstodecline，itisnotnecessarilvasignofadecayduetobecomingoldor“senility”．Oftenitissimplyasignofadepressedemotionalstate．Thisdepressionusuallycanbegotridofbycounseling(咨询)withapsychologist，ormedicinewhichfightsdepression.
InAmericansociety，whenanolderpersonlosessomething，wetendtocallhimorher“senile”．Butnoticethatwhenayoungerpersonlosessomething，hedoesnotblameitonsenilityorlossofmemory．Hefindssomeotherexcuse!
小题1:Along-termstudyof136pairsoftwinsshowedthattheonlyfactorthatdeclinedovertheyearswas .