Working memory decline in normal aging: Is it really worse in space than in color?

Abstract

Aging is associated with a variety of changes in cognitive capacities, including a decline in working memory performance. Nevertheless, visuo-spatial working memory has been shown to exhibit a greater age-related decline than verbal working memory. Here, we assessed age-related changes in allocentric spatial working memory and color working memory. We tested 20–30-year-old and 65–75-year-old adults on four memory tasks requiring participants to learn, on a repeated-trial basis (i.e., reference memory) or a trial-unique basis (i.e., working memory), the locations or colors of three pads among 18 pads distributed in a real-world laboratory environment. Older adults performed worse than young adults on all memory tasks, but especially on working memory tasks. Some measures, including the older adults’ relative decrease in the number of correct choices before erring (CBE), as compared to young adults, and the number of trials with the first or first two choices correct, may suggest a greater age-related decline in allocentric spatial than color working memory. In contrast, the total number of disks visited to find the goals, the absolute decrease in CBE in older adults, the number of errorless trials and the number of trials with the first three choices correct revealed no age-related differences in working memory performance for spatial versus color information. We discuss how, depending on the measures used to evaluate memory performance, age-related declines in working memory may appear greater for spatial information because allocentric spatial memory may have quantitatively greater representational demands (i.e., require more bits of information) than color memory.