Rebecca Spencer, psychological and brain sciences, recently received a two-year, $423,208 grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, with co-investigator Tracy Riggins at the University of Maryland, to study the role of sleep and brain maturation on memory in early childhood development, specifically when children transition out of naps.
At the same time, they also received a three-year, $599,075 grant from the National Science Foundation for a complementary longitudinal investigation where she and Riggins will continue to follow the children as they transition out of naps. Collectively the investigations are expected to “deepen understanding of how sleep benefits learning and memory in healthy children, providing benefit to healthy child care, pre-school education and children with developmental and mental disorders.”
The work is part of Spencer’s years-long investigations into the role of sleep in children. In adults, sleep promotes memory consolidation, the processing of memories that strengthens them and makes them less vulnerable to interference. It’s known that sleep is important for brain plasticity in young adults, the researchers point out, but less is known about the function of sleep in children. Naps benefit learning and memory in young children, Spencer notes. However, children transition out of naps during preschool years and whether naps should be encouraged in preschools or eliminated to provide more time for early learning is not clear.
“These grants will allow us to develop models to test the idea that changes in the brain will lead to changes in sleep patterns and that improved sleep will improve memory,” she says.
Spencer and Riggins point out, “Although we have provided behavioral demonstration of sleep-dependent consolidation in young children, the neural mechanisms supporting this process have yet to be examined.” This gap is significant because both memory and the hippocampal-cortical network supporting it are undergoing significant developmental change during this period, they add.
Using magnetic resonance imaging at Maryland, the researchers will study neural mechanisms supporting sleep-dependent memory consolidation in children. The processes are thought to reflect hippocampal-neocortical transfer of memories and to be related to physiological events in non-REM sleep.
Spencer says, “Our main idea is that as the hippocampus is maturing in early childhood, it enhances memory so more information is retained without interference, which then reduces the need for frequent consolidation. We think this is what is happening when a child transitions from napping to no longer needing a nap.”
The researchers hope that by identifying the mechanisms of how sleep benefits learning and memory in young children, sleep can provide another tool for enhancing education, particularly for children with developmental disorders and psychopathologies. Further, as they point out, “there are no formal recommendations regarding naps for this age group.” This research will lay the groundwork for developing recommendations for typically developing children and nap-based interventions for others such as at-risk and learning delayed children.