Development of sensorimotor integration in children

描述（由申请人提供）：本研究项目的总体长期目标是了解构成感觉运动行为基础的内部模型或表征的发展。先前的研究表明，所谓的感觉运动内部模型，或地图，是控制目标导向运动的基础。这些地图可以被概念化为眼睛（用于视觉）或头部（用于听觉）坐标帧到控制效应器的神经命令的计算转换，例如在以手为中心的坐标中。迄今为止，关于感觉运动图的发展及其相互作用的研究还很缺乏。具体目标1是确定运动-运动或听觉-运动内部表征（模内状况）发展的特征。具体目标2是确定5至10岁儿童的运动-视觉-运动或听觉-视觉-运动内部表征（多式联运状况）的发展。不同模式的内部模型相互作用的神经基础被认为存在于后顶叶皮层，那里的神经元被证明编码视觉和听觉信号，并将它们映射到以手为中心的坐标上。这些实验将允许确定内部和多式联运运动地图分化的特征，并获得这些特征的发展景观。pi假设：(1)幼儿的模态内运动表征非常广泛，导致相当大的表现可变性；(2)随着年龄的增长，这些内部表征变得更好地“调谐”；(3)在多模态环境中，定义不明确的感觉运动表征更容易受到定义较好的内部模型的影响。初步结果表明，幼儿在视觉运动适应条件后的听觉运动后遗症比年龄较大的儿童更强，而年龄较大的儿童可能有更好的模内感觉运动模型。这项工作的总体意义在于解决了两个知识空白，这两个知识空白阻碍了我们更好地了解儿童感觉运动表征是如何发展和相互作用的。了解这一点是未来研究发育性运动障碍如发育性协调障碍（DCD）的重要基础。

DESCRIPTION (provided by applicant): The overall long-term objective of this research program is to understand the development of internal models or representations that underlie sensorimotor behavior. Previous research suggests that so-called sensorimotor internal models, or maps, are the basis for the control of target-directed movements. These maps can be conceptualized as computational transformations of eye- (for vision) or head-centered (for audition) coordinate frames to neural commands controlling the effector e.g. in hand-centered coordinates. To date, studies about the development of sensorimotor maps, and their interactions are lacking. Specific aim 1 is to determine the characteristics of the development of either kinesthetic-motor or auditory-motor internal representations (intramodal condition). Specific aim 2 is to determine the development of either kinesthetic-visuo-motor or auditory-visuo-motor internal representations (intermodal condition) in 5 to 10 year old children. A neural basis for interactions of internal models of different modalities is suggested in the posterior parietal cortex, where neurons have been shown to code both visual and auditory signals and map them onto hand-centered coordinates. These experiments will allow determination of the characteristics of intra- and intermodal motor map differentiation, and to obtain a developmental landscape of these characteristics. The PIs hypothesize that (1) intramodal motor representations are very broadly tuned in young children, resulting in considerable performance variability; (2) with increasing age, these internal representations become better 'tuned'; and (3) in intermodal contexts the less well-defined (intramodal) sensorimotor representations are more susceptible to being affected by better defined internal models. This is supported by preliminary results showing stronger auditory-motor aftereffects after a visuo-motor adaptation condition in young children than in older children, who are likely to have better-tuned intramodal sensorimotor models. The overall significance of the work proposed lies in addressing two knowledge gaps that stand in the way of having better insights into how sensorimotor representations develop and interact in children. Understanding this is an essential foundation for future work on developmental motor impairments such as developmental coordination disorder (DCD).