Manyofusbelievethataperson’smindbecomeslessactiveashegrowsolder.Butthisisnottrue,accordingtoDrJarvik,professorofpsychiatryattheUniversityofCalifornia.Shehasstudiedthementalfunctioningofagingpersonsforseveralyears.Forexample,oneofherstudiesconcerns136pairsoftwins(双胞胎),whowerefirstexaminedwhentheywerealready60yearsold.AsDrJarvikcontinuedthestudyofthetwinsintotheir70sand80s,theirmindsdidnotgenerallydecline(衰弱)aswasexpected. However,therewassomedeclineintheirpsycho-motorspeed.Thismeansthatittookthemlongertofinishmentaltasksthanitusedto.Butwhenspeedwasnotafactor,theylostverylittleintellectual(智力的)abilityovertheyears.Ingeneral,DrJarvik’sstudieshaveshownthatthereisnodeclineinknowledgeorreasoningability.Thisistruenotonlywiththoseintheir30sand40s,butwiththoseintheir60sand70saswell. Itistruethatolderpeoplethemselvesoftencomplainthattheirmemoryisnotasgoodasitoncewas.However,muchofwhatwecall“lossofmemory”isnotthatatall.Thereusuallywasincompletelearninginthefirstplace.Forexample,theolderpersonperhapshadtroublehearing,orpoorvision,orwastryingtolearnthenewthingattoofastaspeed.Inthecaseswheretheolderperson’smindreallyseemstogetworse,itisnotnecessarilyasignofdeclineduetooldage.Oftenitissimplyasignofasademotionalstate. 小题1:Thispassageismainlyabout_______. |