Sleep and Selective Memory Consolidation in Infants: Exploring the Impact of Learning Contexts

Post-encoding sleep facilitates memory consolidation from early infancy. Learning from digital content might also benefit from post-encoding sleep. However, infants find it more difficult to learn and remember screen content (transfer deficit) and may only recognize its relevance when scaffolded by caregivers. We investigated infants' memory performance as a function of presentation mode (live or video), post-encoding sleep, and caregiver scaffolding with the aim of replicating the transfer deficit and the beneficial effect of a post-encoding nap. We expected the nap benefit to be less pronounced when information was encoded from videos. We compared data from a live (n = 68) and a video experiment (n = 69). In both experiments, 15- and 24-month-olds watched demonstrations of two deferred imitation tasks (live or on prerecorded video). During one of the demonstrations, caregivers scaffolded the task. Half of the infants in each age-group napped for ≥ 30 min after demonstration, whereas the others remained awake for ≥ 4 h. Memory performance was assessed after 24 h counting the reproduced target actions. Contrary to expectations, the nap benefit did not replicate in the live demonstration sample. However, when both samples were examined together there was a main effect of nap condition showing that infants who had napped retrieved more target actions than awake infants. Moreover, cross-experiment comparisons revealed a transfer deficit and an unexpected disruptive effect of caregiver scaffolding on memory performance in 15-month-olds. Results are discussed in light of limits on detecting sleep-mediated memory effects and the challenges of remembering digital information in infancy due to cognitive load.