Effect of aging on prospective and incidental memory.

Three experiments were conducted to test the effect of aging on prospective and incidental memory. In the first study, 24 undergraduates (M = 19.71 years) and 17 Elderhostel participants (M = 69.06 years) were used to test three hypotheses: (1) Younger subjects will be superior to older subjects in incidental memory. (2) If older and younger subjects have access to external memory aids, older subjects will display significantly better prospective memory. (3) If these subjects are denied external aids, the younger subjects will exhibit better prospective memory. Hypotheses 1 and 2 were confirmed, but 3 was not. The advantage older subjects display when permitted use of memory aids could derive from better recall of the future task or higher motivation to complete the task once it is recalled. In the second experiment, 51 undergraduates (M = 18.71 years) and 55 older subjects (M = 71.87 years) recruited from a continuing education program were used to test the hypothesis that the advantage older subjects displayed in aided prospective memory over younger ones derives from better recall of the task. The results obtained were not consistent with this interpretation. In the third experiment, 22 undergraduates (M = 18.50 years) and 20 Elderhostel participants (M = 70.25 years) tested the hypothesis that the advantage older subjects enjoy in prospective memory derives from greater motivation to complete the task. This hypothesis was confirmed.