Normative shifts of cortical mechanisms of encoding contribute to adult age differences in visual-spatial working memory

► We examine visual-spatial working memory encoding in younger and older adults. ► Early stimulus processing is boosted in older, but not in younger adults. ► Older adults show less attentional focus during encoding. ► Age differences during encoding predict age differences in working memory capacity. ► Age-related shift of encoding underlies age-related declines in working memory.