Longitudinal Investigation of Sleep, Memory, and Brain Development Across the Nap Transition

项目摘要 睡眠可以稳定大脑皮层区域的记忆，优化突触组织，释放海马体 for ongoing持续learning学习.在儿童早期，小睡起着重要的作用，通过睡眠增强记忆力- 依赖性记忆巩固鉴于此，目前还不清楚为什么孩子们在午睡时会过渡到午睡。 仍然处于一个充满学习的阶段。我们预测，关键的大脑发育发生在这个时候， 中午“卸载”记忆不再重要。在这里，我们提出了第一个纵向研究的 伴随午睡过渡的认知、生理和神经变化。核心假设是， 在儿童早期，大脑（特别是海马体）的成熟导致更多的信息被 不受干扰地保留，减少了在国家行动方案期间频繁合并的需要。我们断定 这些变化有助于双相（午睡和过夜睡眠）到双相（过夜睡眠）睡眠 过渡为了验证这一点，我们将招募180名参与者（36-54个月），并使用纵向设计， 评估大脑发育与记忆、睡眠生理和午睡过渡期的午睡状态的关系。 午睡状态将通过体动记录仪进行实时监测，并通过父母报告的生态瞬时值进行验证。 评估。将在午睡和夜间睡眠期间使用多导睡眠图评估睡眠。记忆将 通过记忆相似性任务进行评估，该任务旨在挖掘与记忆有关的记忆。评估 将在小睡之前和之后发生（与对照组相同的清醒时间间隔），并在小睡之前和之后再次发生 随后的夜间睡眠。大脑的宏观/微观结构和解剖/功能连接将是 用MRI测量。目的1是确定预测从双相睡眠到单相睡眠转变的神经标志物。 目的2是检查睡眠过渡期间睡眠依赖性记忆处理的变化。目标3是 检查昼夜睡眠微结构和睡眠过渡期间地形的变化。目的 4是检查睡眠结构，记忆和大脑之间的相互关系，在睡眠过渡期间使用 潜在变化评分模型。拟议工作的创新方面包括：实时跟踪NAP 在同一受试者中纵向过渡;检查午睡和过夜睡眠的微观结构， 地形图;大脑发育的全面和有针对性的措施;测量大脑介导的 记忆;和潜在变化分数建模。这项工作还将产生一个新的和丰富的数据集， 我们小组和其他人的分析，以测试替代结果，探索额外的大脑的贡献， 区域，并评估其他突出的睡眠理论的其他假设。这项工作将具有重大意义 通过加强对睡眠调节机制的理解， 睡眠对认知健康和表现的影响，以及睡眠中生物标志物的识别， 可能有助于确定风险和健康结果。

PROJECT SUMMARY Sleep stabilizes memories in cortical regions and optimizes synaptic organization, freeing up the hippocampus for ongoing learning. In early childhood, naps serve a critical function, enhancing memory through sleep- dependent memory consolidation. Given this, it remains unknown why children transition out of naps when they are still in a stage rich with learning. We predict that critical brain development occurs at this time, making the mid-day “unloading” of memories no longer essential. Here we propose the first longitudinal study of the cognitive, physiological, and neural changes that accompany the nap transition. The central hypothesis is that maturation of the brain (in particular, the hippocampus) during early childhood results in more information being retained without interference, reducing the need for frequent consolidation that takes place during naps. We posit that these changes contribute to the biphasic (nap and overnight sleep) to monophasic (overnight sleep) sleep transition. To examine this, we will recruit 180 participants (36-54 months) and use a longitudinal design to assess brain development in relation to memory, sleep physiology, and nap status across the nap transition. Nap status will be monitored in real-time with actigraphy and verified via parent-reported ecological momentary assessments. Sleep will be assessed with polysomnography during the nap and overnight sleep. Memory will be assessed with a mnemonic similarity task, designed to tap hippocampal-dependent memory. Assessments will occur before and after a nap (with an equivalent interval awake as a control) and again before and after subsequent overnight sleep. Brain macro/micro structure and anatomical/functional connectivity will be measured with MRI. Aim 1 is to identify neural markers that predict the shift from biphasic to monophasic sleep. Aim 2 is to examine changes in sleep-dependent memory processing across the sleep transition. Aim 3 is to examine changes in diurnal and nocturnal sleep microstructure and topography across the sleep transition. Aim 4 is to examine interrelations among sleep architecture, memory, and the brain across the sleep transition using latent change score modeling. Innovative aspects of the proposed work include: real-time tracking of nap transitions longitudinally within the same subjects; examination of nap and overnight sleep microstructure and topography; comprehensive and targeted measures of brain development; measures of hippocampal-mediated memory; and latent change score modeling. This work will also result in a novel and rich dataset for additional analyses by our group and others to test alternative outcomes, explore the contribution of additional brain regions, and assess additional hypotheses from other prominent sleep theories. This work will have significant implications for human health by enhancing understanding of the mechanisms underlying sleep regulation and the consequences of sleep on cognitive health and performance and identification of biomarkers in sleep which may be useful in identifying risk and health outcomes.