Aging and prospective memory: differences between naturalistic and laboratory tasks.

The contrasting age-related trends on laboratory and naturalistic prospective memory (PM) studies were investigated with the same participants. In the first two experiments, 380 participants in three age groups (20s, 60s, and 80+) were given a naturalistic PM task of logging the time at four set times for one week. There were six between-subjects regimens that varied the complexity of the time schedule, and the opportunity to use conjunction cues and external aids. The 60s and 80+ age groups did not differ and both older adult age groups were consistently superior to the young adults on all regimens. In Experiment 3, the same participants showed a significant age-related decline on retrospective memory tasks, and on event-based and time-based laboratory PM tasks embedded within the retrospective memory tasks. The study confirmed the paradoxical age-related trends on laboratory and naturalistic PM tasks.