Age-related dynamics of cognitive brain functions in humans: an electrophysiological approach.
Event-related P300 potentials closely reflect cognitive functions such as stimulus discrimination (N250) and processing time (P300 latencies) as well as attention capabilities (P300 amplitudes). To delineate the age-related dynamics of P300 potentials, we investigated 250 healthy subjects between 18 and 98 years of age in a cross-sectional study. A total of 330 visual P300 tests was performed in two different paradigms (PI, passive condition, n = 80; PII, active condition, n = 250). In both P300 paradigms, the N250 and P300 latencies were markedly prolonged (p < .0001) in older age, whereas the N250 and P300 latency differences between PII and PI did not change (p > .05). The P300 amplitudes in paradigm I and II revealed only a slight age-related reduction. In fact, the P300 amplitude ratios between PII and PI remained constant. Third-order polynomial regressions provided the best fit of the aging-P300 interactions in paradigms I and II for both males and females. Interestingly, females showed a greater and possibly earlier P300 latency increase during aging than males. These age-related changes of P300 potentials indicate a rather mild cognitive decline that does not accelerate before old age and may be different between both sexes.
University of Erlangen-Nürnberg, Second Department of Internal Medicine, Germany.
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Kügler
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Petter
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Platt
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis