Effects of aging, planning, and interruption on complex prospective memory.

This study examined the effects of aging, planning, and interruption on complex prospective memory (PM) using a 2 x 2 x 2 between-subjects design. Participants were 80 younger adults (65 females) aged 18-33 years and 80 older adults (70 females) aged 60-75 years. They were randomly allocated to four conditions (viz., no interruption and no planning, interruption but no planning, planning but no interruption, and both planning and interruption) and asked to undertake three PM tasks (time-, event-, and activity-based) while performing an ongoing task (viz., recipe checking and identification) in a simulated home environment. Younger adults were found to perform significantly better than older adults on time- and event-based PM. The opportunity to plan for five minutes was found to improve performances on all three types of PM. Unexpected, external interruptions, on the other hand, were found to reduce performance for time-based PM. Interestingly, planning was found to significantly improve the performance of older adults on time-based PM and to a level similar to that of younger adults. Results of the study have clarified the independent and interactive effects of the three variables on PM and have implications for understanding and enhancing this type of memory.