The influence of semantics on long-term visual memory capacity in children and adults

Human visual memory capacity has a rapid developmental progression. Here we examine whether image semantics modulate this progression. We assessed the performance of children (6–14 years) and young adults (19–36 years) on a visual memory task using real-world (or meaningful) as well as abstract image sets, which were matched in low-level image attributes. For real images, we find comparable performance across the two age groups, consistent with previously reported results. However, for abstract images, we find a clear age-related difference indicating greater reliance of children's memory processes on semantics, suggesting that strategies for encoding abstract patterns keep improving even into late childhood. We complemented these studies with computational experiments designed to examine the role of increasing experience with real-world images on real and abstract image encoding, to examine whether the observed age-related differences, as well as the general privilege of real over abstract images, can emerge directly through experience with meaningful images. Our results provide support for this possibility and set the stage for a finer-grained investigation of the timeline along which children's memory capacity for abstract images reaches adult levels.