Age-related differences in the neural correlates of remembering time-based intentions.

The present study used event-related potentials (ERPs) to explore the effect of age on the neural correlates of monitoring processes involved in time-based prospective memory. In both younger and older adults, the addition of a time-based prospective memory task to an ongoing task led to a sustained ERP activity broadly distributed over the scalp. Older adults, however, did not exhibit the slow wave activity observed in younger adults over prefrontal regions, which is considered to be associated with retrieval mode. This finding indicates that age-related decline in intention maintenance might be one source of the impaired prospective memory performance displayed by older adults. An 'anterior shift' in scalp distribution of the P3 was observed in older adults, and was related to lower levels of accuracy in prospective memory performance. This relationship suggests that possible factors responsible for age-related decline in prospective memory performance include the decreased efficiency of executive/frontal functions as well as the reduced amount of resources available for the prospective memory task.