Age-related differences in working memory: ERPs reveal age-related delays in selection- and inhibition-related processes |
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Authors: | Yuji Yi David Friedman |
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Institution: | Cognitive Electrophysiology Laboratory, Division of Cognitive Neuroscience, New York State Psychiatric Institute, New York, NY, USA |
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Abstract: | Faulty inhibition is implicated in age-related working memory decline. ERP signs of selection and inhibition of items in working memory (WM) are, respectively, a cue-locked parietal positivity (~350 ms) and a probe-locked frontal negativity (~520 ms). To determine when in the older age range differences in selective and inhibitory processes might occur, ERPs were recorded in a WM task from 20 young (20–28), 20 young–old (60–70), and 20 old–old (71–82) adults. A 4-digit display was followed by a cue indicating which 2 of 4 digits were relevant. Proactive interference (PI), the reaction time difference between a matching and non-matching to-be-ignored digit was larger, relative to the young, in both older groups. Compared to the young, both the cue- and probe-locked activities were prolonged in the older groups. Although there were no topographic differences among the age groups, the prolonged PI and associated ERPs suggest a relative age-related deficit in inhibition. |
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Keywords: | Working memory Proactive interference Cognitive aging Selection Event-related potential |
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