简介：Thebrainasasystemwithgraduallydecreasingresourcesmaximizesitschancesbyreorganizingneuralnetworkstoensureefficientperformance.Auditoryevent-relatedpotentialswererecordedin28healthyvolunteerscomprising14youngand14elderlysubjectsinauditorydiscriminationmotortask(lowfrequencytone-righthandmovementandhighfrequencytone-lefthandmovement).Theamplitudesofthesensoryevent-relatedpotentialcomponents(N1,P2)weremorepronouncedwithincreasingageforeithertoneandthiseffectforP2amplitudewasmorepronouncedinthefrontalregion.ThelatencyrelationshipofN1betweenthegroupswastone-dependent,whilethatofP2wastone-independentwithaprominentdelayintheelderlygroupoverallbrainregions.Theamplitudesofthecognitivecomponents(N2,P3)diminishedwithincreasingageandthehemisphericasymmetryofN2(butnotforP3)reducedwithincreasingage.ProlongedN2latencywithincreasingagewaswidespreadforeithertonewhilebetween-groupdifferenceinP3latencywastone-dependent.HighfrequencytonestimulationandmovementrequirementsleadtoP3delayintheelderlygroup.Theamplitudedifferenceofthesensorycomponentsbetweentheagegroupscouldbeduetoageneralgreateralertness,lessexpressedhabituation,ordeclineintheabilitytoretreatattentionalresourcesfromthestimuliintheelderlygroup.Withaging,aneuralcircuitreorganizationofthebrainactivityaffectsthecognitiveprocesses.Theapproachusedinthisstudyisusefulforanearlydiscriminationbetweennormalandpathologicalbrainagingforearlytreatmentofcognitivealterationsanddementia.