Neurocognitive Markers of Developing Executive Control and Risk for ADHD in Preschool

 描述(由申请人提供)：学龄前几年标志着发展精神病理学出现的关键时期，包括与ADHD相一致的症状维度。然而，在儿童早期有效检测这类心理健康问题的评估工具是有限的，部分原因是对早期前体和神经基础没有很好的了解。学龄前儿童的神经认知发展迅速，反映在幼儿的执行控制能力和执行控制能力的个体差异上 突出表现为精神健康障碍和功能障碍，使其成为早期评估/干预的潜在重要目标。最近的EC发展模型表明，学龄前儿童的执行任务表现主要是由“自下而上”的刺激/反应过程驱动的，在四岁左右发生质变之前，“自上而下”的执行过程开始影响行为表现。目前尚不清楚在这一关键转变前后这些互补过程的确切神经生理学机制是什么，以及在有金属健康问题风险的儿童中它们可能有什么不同。长期目标是解释在整个发育转变过程中这些过程背后的神经生理学机制，并了解它们如何与儿童精神病理学的风险相关。这项拟议的研究的目的是表征典型发育儿童在过渡前后各自机制的不同神经生理学特征，并确定这些特征在过渡后表现出ADHD症状的儿童中的差异。其基本原理是，这些知识将为这些机制在不同发育阶段和临床样本中如何发挥作用提供信息，为未来的纵向研究和干预奠定基础。中环 假说是，“自下而上”刺激/反应处理的明显神经生理学特征将在过渡前后被识别，但与“自下而下”EC相关的神经活动只会在较晚的年龄观察到，并在有ADHD症状的儿童中进一步减弱。本研究的具体目的是：1)表征学龄前儿童“自下而上”和“自上而下”过程的神经生理学特征；2)确定反映“自下而上”和“自上而下”过程的神经生理学特征在预测3.5岁和5岁儿童特定和一般ADHD症状维度方面的相对能力。该项目的目标是测量与EC相关的大脑活动，这是一项创新 在这一关键年龄范围内研究ADHD的风险，并在构成假设基础的复杂统计模型的框架内做到这一点。这项研究的意义在于，它将解释学龄前幼儿EC发展的质变背后的机制，并确定这些机制中的个体差异如何与儿童精神病理学的风险相对应。这项工作将阐明EC作为早期评估/干预的关键目标的重要性，并最终加强国民心理健康。

 DESCRIPTION (provided by applicant): The preschool years mark a critical period for the emergence of developmental psychopathology, including symptom dimensions consistent with ADHD. However, the availability of assessment tools to effectively detect such mental health problems early in childhood is limited, in part because the early precursors and neural bases are not well understood. The preschool period is characterized by rapid neurocognitive development reflected in young children's executive control (EC) capabilities, and individual differences in EC figure prominently into mental health disorder and functional impairment, making it a potentially important candidate to target for early assessment/intervention. Recent developmental models of EC suggest that executive task performance in younger preschoolers is driven primarily by "bottom-up" stimulus/response processing before a qualitative shift occurs around age four, after which "top-down" executive processes begin to contribute to behavioral performance. It is unknown what the precise neurophysiological mechanisms of these complimentary processes are before and after this critical transition, and how they might differ in children at risk for metal health problems. The long-term goal is to explicate the neurophysiological mechanisms underlying these processes across this developmental transition and understand how they relate to risk for child psychopathology. The objective of the proposed research is to characterize distinct neurophysiological signatures of the respective mechanisms in typically developing children before and after the transition, and to identify differences in these signatures in children displaying ADHD symptoms after the transition. The rationale is that this knowledge will inform how these mechanisms function at different developmental stages and in a clinical sample to lay the groundwork for future longitudinal study and intervention. The central hypothesis is that distinct neurophysiological signatures of "bottom-up" stimulus/ response processing will be identifiable before and after the transition, but neural activity related to "to-down" EC will only be observed at later ages and further be diminished in children with ADHD symptoms. The specific aims of the research are to: 1) Characterize the neurophysiological signatures of "bottom-up" and "top-down" processes in younger and older preschoolers; 2) Determine the relative power of the neurophysiological signatures reflecting both "bottom-up" and "top-down" processes in predicting specific and general ADHD symptom dimensions in 3.5- and 5-year-olds. The project is innovative in its objective to measure brain activity related to EC and ADHD risk in this critical age range, and to do so within the framework of sophisticated statistical models which form the basis of the hypotheses. The significance of this research is that it will explicate the mechanisms underlying the qualitative shift in preschool EC development and identify how individual differences in these mechanisms correspond to risk for child psychopathology. This work will clarify the importance of EC as a critical target for early assessment/intervention and ultimately enhance national mental health.