The influence of working memory performance on event-related potentials in young and older adults

Variations in brain activation may lead to individual differences in working memory (WM) performance. Such differences may account for contradictory findings in the literature relating to age-related changes in neural activation during WM tasks. In the present study, 39 young adults (aged 18-30) and 34 older adults (aged 65+) completed an n-back task while their electroencephalography, accuracy, and reaction time was recorded. They were then categorized as high or low performers. High performers had larger P3b and parietal P200 amplitudes and smaller parietal N200 amplitudes than low performers. High-performing older adults exhibited larger parietal P200 amplitudes than low-performing older adults, and similar P3bs to young adults during the 2-back. Low-performing older adults, in contrast, exhibited smaller parietal P3bs than young adults during the 2-back. These findings suggest that brain activity during a WM task is influenced by individual differences in performance level. Moreover, some older adults can maintain high WM performance and capacity through recruitment of additional brain regions.