Integrating across episodes: Investigating the long-term accessibility of self-derived knowledge in 4-year-old children.

Semantic memory, defined as our store of knowledge about the world, provides representational support for all of our higher order cognitive functions. As such, it is crucial that the contents of semantic memory remain accessible over time. Although memory for knowledge learned through direct observation has been investigated previously, we know very little about the retention of knowledge derived through integration of information acquired across separate learning episodes. The current research investigated cross-episode integration in 4-year-old children. Participants were presented with novel facts via distinct story episodes and tested for knowledge extension through cross-episode integration as well as for retention of the information over a 1-week delay. In Experiment 1, children retained the self-derived knowledge over the delay, although performance was primarily evidenced in a forced-choice format. In Experiment 2, we sought to facilitate the accessibility and robustness of self-derived knowledge by providing a verbal reminder after the delay. The accessibility of self-derived knowledge increased irrespective of whether participants successfully demonstrated knowledge of the integration facts during the first visit. The results suggest that knowledge extended through integration remains accessible after delays even in a population where this learning process is less robust. The findings also demonstrate the facilitative effect of reminders on the accessibility and further extension of knowledge over extended time periods.