Individual Differences in the Development of Spatial Skills: Role of Hippocampal Function and Structure

记住你把钥匙放在哪里，在拥挤的停车场找到你的车，在地图上定位物品，在不熟悉的社区导航，这些都需要空间技能，如空间记忆，导航和重新定位。这些空间技能是对生存至关重要的适应功能。海马体已经被公认为是动物和成年人空间技能所必需的神经结构。相比之下，海马的功能和结构如何与儿童的各种空间技能有关，人们对此知之甚少。众所周知，与学龄儿童和成人相比，学龄前儿童在空间任务上往往表现不佳，这表明他们的大脑可能还不够成熟，无法处理这些任务的要求。不幸的是，这些研究主要集中在年龄组之间的差异（例如，4岁和6岁），这使得我们在理解这一发展跨度中存在的个体差异以及可能导致这种差异的潜在神经机制方面存在知识差距。因此，为了解决我们知识中的这一差距，本研究将研究空间技能发展的个体差异，以及这些差异是否可以通过海马功能和结构的发育变化来解释。具体而言，在拟议的4年R 01赠款中，该项目利用208名4岁、5岁和6岁儿童的经济和种族/种族多样化样本，旨在：（1）通过采用海马依赖性联想学习任务（即，（2）确定空间任务的个体差异是否可以通过海马结构的个体差异来解释，海马结构包括子域体积、神经突密度、皮质髓鞘和海马-皮质连接，其通过使用横截面样本的结构磁共振成像来测量，以及;（3）使用一组4岁儿童，在6岁时纵向观察海马功能和结构的变化，这些变化导致空间技能的获得和发展。因此，拟议的补助金提供了一个框架，以确定海马功能和结构，在一个发展中的人口没有以前的研究和研究的作用，海马在儿童的发展空间能力。除了进一步了解海马体在儿童发展空间技能中的作用外，拟议研究的结果还将为未来研究海马体结构和功能的典型和非典型工作奠定基础（例如，威廉姆斯综合征）的发展中人群，以及未来的工作检查级联认知后果（即，空间工作记忆;空间焦虑）海马发育的个体差异。

PROJECT SUMMARY/ABSTRACT Remembering where you left your keys, finding your car in a crowded parking lot, locating items on a map, and navigating through an unfamiliar neighborhood are all tasks that require spatial skills, such as spatial memory, navigation, and reorientation. These spatial skills are adaptive functions that are critical for survival. The hippocampus has been well established as a neural structure that is essential for spatial skills in both animals and human adults. In contrast, relatively little is known about how hippocampal function and structure relates to various spatial skills in children. It is know that, compared to school-aged children and adults, preschool children tend to perform poorly on spatial tasks, suggesting that their hippocampi may not be mature enough to process the demands of such tasks. Unfortunately, these studies have only primarily focused on differences between age groups (e.g., 4-year-olds vs. 6-year-olds) leaving a knowledge gap in our understanding of the individual differences that exists in performance across this span of development, as well as the underlying neural mechanisms which may contribute to this variability. Therefore to address this gap in our knowledge, the current study will examine individual differences in the development of spatial skills and whether these differences can be explained by developmental changes in hippocampal function and structure. Specifically, in the proposed 4-year R01 grant, the project, utilizing an economically- and ethnically/racially-diverse sample of 208 4-, 5-, and 6-year-olds aims to: (1) determine whether individual differences on spatial tasks can be explained by individual differences in hippocampal function by employing a hippocampal-dependent associative learning task (i.e., EBC) using a cross-sectional sample; (2) determine whether individual differences on spatial tasks can be explained by individual differences in hippocampal structure, including subfield volume, neurite density, cortical myelin, and hippocampal-cortical connectivity, measured via structural magnetic resonance imaging using a cross- sectional sample, and; (3) characterize changes in hippocampal function and structure that result in gains in and development of spatial skills using a cohort of 4-year-olds that will be observed longitudinally at 6 years of age. Thus, the proposed grant provides a framework for identifying hippocampal functioning and structure in a developing population not previously studied and for examining the role of the hippocampus in children’s developing spatial competence. In addition to advancing knowledge about the role of the hippocampus in children’s developing spatial skills, results from the proposed research would lay the foundation for future work addressing hippocampal structure and functioning in both typical and atypical (e.g., Williams Syndrome) developing populations, as well as future work examining the cascading cognitive consequences (i.e., spatial working memory; spatial anxiety) of individual differences in hippocampal development.