Developmental differences in reactivation underlying self-derivation of new knowledge through memory integration.

Self-derivation of novel facts through integration of memory content is fundamental to acquiring new knowledge and a means of building a semantic knowledge base. It involves combining memory content acquired across separate episodes of learning to generate new knowledge that was not explicitly taught in either episode. To self-derive, one needs to reactivate earlier learned memory content upon exposure to related content and then integrate the learning episodes. Previous research found developmental differences in the conditions under which integration occurs. Adults spontaneously integrate whereas 7- to 9-year-old children seemingly integrate only upon direct tests that verbally prompt for integration. Yet it is unclear whether children engage in the preliminary process of reactivation prior to the direct tests. To address this gap in the current research, we developed an eye-tracking paradigm and tested whether adults and 7- to 9-year-old children engage in the process of reactivation prior to direct tests. The direct tests verbally prompted for integration of memory content requiring self-derivation through both open-ended and forced-choice formats. Both adults and children engaged in reactivation prior to the direct tests. The extent of their reactivation predicted their performance on the direct tests. However, adults showed stronger evidence of reactivation and performed better than children on the direct tests. This work contributes to understandings of developmental differences in the underlying processes involved in the development of new knowledge.