From general to specific: The development of efficient prospective memory strategies

Prospective memory is the ability to remember previously set intentions at the right moment and is essential for goal achievement. This core ability develops markedly during childhood and adolescence. But little is known about the development of strategic processes involved in monitoring for the right moment to execute the intention. Strategic monitoring is thought to come at cost for the ongoing task compared to spontaneous retrieval of the prospective memory task. We hypothesized that a developmental progression occurs in strategic monitoring. To test this hypothesis, we conducted a task switching experiment in a sample of 156 participants; 8-, 10-, and 12- year old children as well as young adults. Participants were instructed to perform three alternating tasks (parity, color, and case decisions) as an ongoing task. In a baseline block, participants performed the ongoing task without prospective memory instructions. Next, participants were instructed for the prospective memory task (i.e., to press a special key if a deviant letter occurred for a case decision). In the first block, the prospective memory task was activated but no target event occurred, while in the second block targets appeared. To control for practice effects we included a third block again without targets. Although no targets appeared in the first block, participants performed the ongoing task slower compared to the baseline block. Adults slowed down predominantly on case decisions while children slowed down on all the tasks. Compared to blocks 1 and 3, there was an immediate slowing after responding to prospective memory targets in the second block. This slowing decreased with age, which speaks for attenuating after-effects with development. Taken together, these findings highlight developmental differences of efficient strategies for prospective memory monitoring in order to maintain performance in an ongoing task.