Accounting for age differences on the Wisconsin Card Sorting Test: decreased working memory, not inflexibility.

Two experiments examined the role of cognitive inflexibility and reduced working memory in age-related declines on the Wisconsin Card Sorting Test. Both standard scoring procedures and newly developed scores were used to measure each construct, and modifications of the test further evaluated the role of working memory. Results indicated that age differences are not due to cognitive inflexibility but that for a subset of older adults errors are associated with a reduction in the amount of information that can be stored or processed in working memory. These age differences disappear, however, when visual cues provide information about the immediately preceding sort. The authors conclude by proposing a decline in updating working memory as the explanation that can best account for the entire pattern of age differences on this test.