Abstract / Summary
Naturalistic visuomotor tasks, like building a Lego model, allow one to trade off the use of external resources (here, looking at the instructions) versus internal resources (remembering steps in working memory). Prior work has revealed substantial individual differences in this sampling-remembering trade-off, with some individuals opting to sample less and remember more (‘heavy-loaders’) and others to sample more and remember less (‘light-lifters’). We hypothesized that these strategies are driven by subjective, but stable, assessments of the costs of sampling versus remembering. In this preregistered, developmental study, we tested this using two superficially different, but isomorphic tablet-based tasks: the Shopping Game and the Zoo Game. Children (N = 121, 60% female, age: 6.0-10.0 years) were shown icons of food items (or animals) and asked to select them in a store (or field) interspersed with distractors. Critically, children could not view the list and store/field simultaneously, but could toggle between them. List Study Time and Memory Use (correctly selected items), per visit, characterized strategy. As expected, we found substantial variability in Memory Use and Study Time between children that remained constant across age (0.5-5 items and 1-12 s, respectively), alongside significant, strong stability within children (>67% variance explained), both across the two tasks and over time (test-retest); heavy-loaders remained heavy-loaders and light-lifters, light-lifters. We also found that cognitive reflection (CRT-D) and age significantly predicted Memory Use. To our knowledge, this is the first study to explicitly characterize the individual differences and cognitive motivation predictors of children's spontaneous memory use.