Researchershaveestablishedthatwhenpeoplearementallyengagedbiochemicalchangesoccurinthebrainthatallowittoactmoreeffectivelyincognitive(认知的)areassuchasattentionandmemory.Thisistrueregardlessofage.
Researchershaveestablishedthatwhenpeoplearementallyengagedbiochemicalchangesoccurinthebrainthatallowittoactmoreeffectivelyincognitive(认知的)areassuchasattentionandmemory.Thisistrueregardlessofage.
Peoplewillbealert（警觉的）andreceptiveiftheyarefacedwithinformationthatgetsthemtothinkaboutthingstheyareinterestedin.Andsomeonewithahistoryofdoingmoreratherthanlesswillgointooldagemorecognitivelysoundthansomeonewhohasnothadanactivemind.
Manyexpertsaresoconvincedofthebenefitsofchallenginginthebrainthattheyareputtingthetheorytoworkintheirownlives.“Theideaisnotnecessarilytolearntomemorizelargeamountsofinformation”saysJamesFozardassociatedirectoroftheNationalInstituteofAgeing.“Mostofusdon’tneedthatkindofskill.Suchspecifictrainingisoflessinterestthanbeingabletomaintainmentalalertness.”Fozardandotherssaytheychallengetheirbrainswithdifferentmentalskillsbothbecausetheyenjoythemandbecausetheyaresurethattheirrangeofactivitieswillhelpthewaytheirbrainswork.
GeneCohenactingdirectorofthesameinstitutesuggeststhatpeopleintheiroldageshouldengageinmentalandphysicalactivitiesindividuallyaswellasingroups.Cohensaysthatwearefrequentlyadvisedtokeepphysicallyactiveasweagebutolderpeopleneedtokeepmentallyactiveaswell.Thosewhodoaremorelikelytomaintaintheirintellectualabilitiesandtobegenerallyhappierandbetteradjusted.“Thepointisyouneedtodoboth”Cohensays.Intellectualactivityactuallyinfluencesbrain-cellhealthandsize.
50.Whatisthepassagemainlyabout?
A.Specialmentaltrainingforoldpeople.
B.Biochemicalchangesinthehumanbrain.
C.Theinfluenceofintellectualactivitiesonbrain-cellsize.
D.Theimportanceofmentalactivitiesintheefficiencyofthebrain.
51.Apersonwhoissaidtobecognitivelyhealthyshould________.
A.bealertandreceptiveinmind B.whoarehighlyintelligent
C.begoodatdoinggroupwork D.rememberlargequantitiesofinformation
52.ThefindingsofJamesandotherscientistsintheirwork_________.
A