Predicting explicit memory for meaningful cartoons from visual paired comparison in infants and toddlers.

We tested the memory of 18-, 33-, and 39-month-olds (N = 120) for dynamic stimulus material (simple cartoons) after 6 months in a visual paired comparison (VPC) task. We also tested the explicit recognition memory (ERM) for the same material. Only the oldest age group (39-month-olds) showed a significant visual (familiarity) preference at the test. Similarly, only the oldest group reliably chose the correct cartoon in the ERM test. Data from the VPC and ERM tasks did not correlate in any age group. However, we suggested a novel score (coined ΔVPC) measuring how much visual preference changes during the test phase in the VPC task. We found that this ΔVPC score (and vocabulary) predicted children's performance in the ERM task, whereas other potential predictors such as age and conventional novelty preference did not. We discuss the impact of these findings in relation to the development of implicit and explicit memory. Furthermore, we propose that VPC measures are associated with explicit memory only when the participants processed the stimuli conceptually. In such cases, we suggest that the ΔVPC score is an approximation of how demanding it is to construct the mental representation of the familiar stimulus during the test phase.