Aging, executive control, and attention: a review of meta-analyses

We review the results of a series of meta-analyses by the first author and colleagues, examining age-related differences in selective attention (Stroop-task survey and negative-priming task survey) and in divided attention (dual-task survey and task-switching survey). The four task families all lent themselves to state trace analysis, in which performance in baseline conditions was contrasted with performance in experimental conditions separately for college-aged subjects and for elderly subjects. These analyses found no age-related deficits specific to selective attention or local task-switching. Age deficits were found for dual-task performance and global task-switching. Unlike selective attention and local task-switching costs, dual-task and global task-switching costs were found to be additive in both young and old subjects, unmodulated by task difficulty. These forms of executive intervention then did not alter computational processes already present in the simple tasks, but rather added one or more additional processing steps or stages to the processing stream. The cost was greater in older adults, but was limited to those. experimental conditions that activated multiple task sets. (C) 2002 Elsevier Science Ltd. All rights reserved.