Collaborative Research: Hippocampal Development and Sleep-Dependent Memory Consolidation in Preschoolers

University Of Maryland, College Park, College Park MD

Investigators

Abstract

Naps benefit learning and memory in young children. However, children transition out of naps during preschool years. Whether naps should be encouraged in preschools, or eliminated to provide more time for early learning, is not clear. The overarching objective of this proposed research is to examine the role of sleep and brain development on memory during early childhood, specifically as children transition out of naps. The central hypothesis of this proposal is that maturation of memory-related brain regions during this transitional developmental period results in more information being retained in memory without interference. This in turn reduces the need for frequent consolidation, which ultimately underlies the transition out of naps. This research will deepen understanding of how sleep benefits learning and memory in healthy children, providing benefit to healthy child care, and pre-school education. Sleep-dependent memory consolidation is thought to reflect transfer of memories from the hippocampus to the cerebral cortex. Although we have previously documented changes in memory performance as a result of sleep-dependent consolidation in young children, the neural mechanisms supporting this process have yet to be examined. This gap is problematic as memory and the hippocampal-cortical network both undergo significant developmental change during this period. Our goal is to identify the mechanistic pathway through which brain development and sleep physiology underlie changes in memory during childhood development. To accomplish this, we will obtain measures of brain structure, brain function, sleep physiology, and memory. We hypothesize that age-related changes in the development of the brain and sleep physiology will result in larger and stronger memories. Likewise, we expect increased hippocampal functional connectivity to allow for more efficient memory transfer with sleep, and will be associated with changes in slow wave sleep. We will use models to test the hypothesis that changes in hippocampal structure will precede changes in hippocampal function; these combined changes will lead to changes in sleep patterns; and that improved sleep will improve memory. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.