These studies are designed to investigate the effects of interference (i.e., changes in performance following an interpolated task) in retention of short periods of time: (1) to determine whether aging results in increased susceptibility to interference; and (2) to explore conditions which affect age differences in interference. In these studies, the task is to identify many presentations of four time periods before and after an interpolated task. In previous studies of this project, old men have been more susceptible to interference than young men. Current studies compare age groups in interference under various experimental manipulations of the interpolted stimuli such as: varying the labeling of the stimuli, no overt judgments in the interpolated task, and presenting interpolated stimuli via a modality different from the visual presentations of the primary task. The most recent studies involve speed of information processing.