Integration of Memory Content in Adults and Children: Developmental Differences in Task Conditions and Functional Consequences

How separate yet related episodes of experience are associated in memory is a major question in cognitive science and cognitive neuroscience. Adults and children both integrate content acquired in separate episodes, yet they may do so under different task conditions. Neuroimaging studies suggest that adults integrate the contents of separate memory traces at encoding and thus without an explicit prompt; behavioral studies suggest that children do so only when specifically prompted. In the present research, we developed a novel paradigm to test integration of memory content using eye-gaze in an indirect (unprompted) test and self-derivation of new factual knowledge based on related facts in direct (open-ended and forced-choice) tests. To permit use of color images to accompany the stimuli, we developed a procedure for equating color images on 23 low-level properties that otherwise might control eye-gaze behavior. We used the paradigm with adults (Experiment 1) and 7- to 9-year-old children (Experiment 2). Both groups succeeded on the direct tests. Among adults, unprompted integration of memory content (in the indirect test) was apparent and supported open-ended self-derivation (in the direct test). Across trials, children did not show evidence of unprompted integration of memory content and performance during the unprompted indirect test did not support open-ended self-derivation; longer looking to target versus foil images during the indirect test was related to direct test performance under forced-choice conditions, however. The patterns indicate that adults and children engage the process of integration of memory content under different task conditions, and that when integration processes take place without an explicit prompt they have different functional consequences for adults and children.