Age differences in updating working memory: Evidence from The Delayed-Matching-to-Sample Test

The Delayed Matching-to-Sample (DMTS) Test was used in four experiments to test the hypothesis that older adults are less able than young to update the contents of working memory. Large age differences in working memory were found whenever there was a delay between presentation and test, and they did not vary as a function of delay length. Increasing the intertrial interval (ITI) reduced interference from the previous trial, but benefited old and young equally. In addition, although age differences in perceptual processing speed were correlated with reduced working memory, incomplete perception of the stimuli could not account for the findings. Together these results demonstrate age differences in updating working memory and the usefulness of the DMTS task to test hypotheses about the nature of these differences. Final discussion centers on the implications of these findings for the frontal lobe hypothesis of aging.