Normal Aging of the Attentional Control Functions That Underlie Working Memory.

OBJECTIVES

This study assessed the effect of aging on 3 attentional control functions (ACFs)--shifting, inhibition, and updating--and on their contribution to working memory (WM) tasks.

METHODS

Complex WM tasks (the Brown-Peterson procedure, the reading span, and the alpha span) and tasks used to derive composite measures of the ACFs were administered to 75 younger and 75 older adults.

RESULTS

Of the 3 ACFs, only inhibition was impaired in aging after controlling for processing speed. Furthermore, the effect of aging on WM tasks was not pervasive, as older adults showed impaired performance on the Brown-Peterson procedure and the reading span but not on the alpha span. When examining the contribution of ACFs to WM in older adults, updating accounted for performance on the Brown-Peterson and reading span tasks, and inhibition was involved in performance on the alpha span task. In younger adults, it was processing speed that contributed the most to WM.

DISCUSSION

This pattern of results suggests that complex WM tasks reflect different ACFs and that this varies as a function of age.