Analyzing Shared Cognitive Risk Factors in Comorbidity

项目总结/摘要 共病在学习障碍（LD）中很普遍（共病率为25-50%）， 预测学术和功能结果，但对认知机制知之甚少， 会增加孩子患多种疾病的风险本项目提出了一个LD的多重赤字模型， 共同的认知风险因素有助于阅读和数学（基本和高阶技能）的共病， 多动症。这个项目的总体目标是使用收敛的方法，包括潜在的建模，实验 方法和行为遗传学，以确定共同的认知危险因素在LD合并症中的作用 ADHD。学习障碍和多动症之间潜在的共同认知缺陷包括： 速度（PS），执行功能（EF）和内隐学习的特定领域。虽然这些因素 每一个都在LD中单独进行了检查，这是第一个评估这些相关结构影响的研究 在LD之间的共患病率。PS结构的一个挑战是度量的“任务不纯”。到 为了解决这一问题，我们将系统地研究4个关于角色的理论模型（一些非排他性的） 在LD和ADHD的PS中：（1）PS可还原为认知g，（2）PS可还原为EF，（3）PS是一个域- 一般因素，（4）PS具有与特定学术技能相关的特定内容成分。要求1 将通过引入新的实验性PS任务并利用现有数据来检查这4个模型， 先进的潜在模型的共享和独特的差异之间的结构。另一个潜在的共享 学习障碍的认知风险因素是内隐学习的缺陷，特别是 程序学习和统计学习，我们还没有在这个样本中研究过。目标1将包括 程序性（基于运动）和统计性（基于语言）学习的新措施。这将是第一 研究，以检查这些结构与多个LD和ADHD的关联。因为这个LD中心 采用遗传敏感的双胞胎设计，我们将能够从最适合的基因中得出遗传推断。 认知模型在目标2中，我们将确定共同的认知风险因素是否也具有遗传性。 与共病LD的关系。美国双语青年人口呈指数级增长，但 我们对这一人群的学术发展仍然知之甚少。在目标3中，我们计划测试最佳拟合 多重缺陷模型从目标1在双语，西班牙裔青年的样本。这一分析将是一个重要的 多重缺陷模型的普遍性检验，其中分歧点将具有重要的临床意义。 影响该项目的重点是识别和剖析LD的共同认知风险因素， ADHD对于评估合并症风险和新的治疗靶点具有临床意义， 影响广义认知风险机制。

PROJECT SUMMARY/ABSTRACT Comorbidity is pervasive among the learning disabilities (LDs) (comorbidity rates of 25-50%) and is a key predictor of academic and functional outcomes, yet little is known about the cognitive mechanisms that increase a child’s risk for multiple disorders. This project proposes a multiple deficit model of LDs where shared cognitive risk factors contribute to comorbidity of reading and math (basic and higher-order skills) and ADHD. The overall goal of this project is to use converging methods, including latent modeling, experimental methods, and behavioral genetics, to identify the role of shared cognitive risk factors in the comorbidity of LDs and ADHD. Potential shared cognitive deficits between learning disabilities and ADHD include processing speed (PS), executive functions (EFs), and specific domains of implicit learning. Although these factors have each been examined in LDs individually, this is the first study to assess the impact of these related constructs on comorbidity across LDs. One challenge with the PS construct is the “task impurity” of the measures. To address this concern, we will systematically examine 4 theoretical models (some non-exclusive) about the role of PS in LDs and ADHD: (1) PS is reducible to cognitive g, (2) PS is reducible to EF, (3) PS is a domain- general factor, (4) PS has content-specific components that are associated with specific academic skills. Aim 1 will examine these 4 models by introducing new experimental PS tasks and leveraging existing data with advanced latent models of the shared and unique variance among the constructs. Another potential shared cognitive risk factor among learning disabilities are deficits in implicit learning, specifically the subdomains of procedural learning and statistical learning, which we have not yet studied in this sample. Aim 1 will include new measures of procedural (motor-based) and statistical (language-based) learning. This will be the first study to examine the association of these constructs with multiple LDs and ADHD. Because this LD center employs a genetically-sensitive twin design, we will be able to draw genetic inferences from the best-fitting cognitive models. In Aim 2, we will determine whether shared cognitive risk factors also share genetic relationships with the comorbid LDs. The population of bilingual youth is growing exponentially in the US, yet we still know very little about academic development in this population. In Aim 3, we plan to test the best-fitting multiple deficit model from Aim 1 in a sample of bilingual, Hispanic youth. This analysis will be an important test of the universality of the multiple deficit model where points of divergence will have important clinical implications. The focus of this project on identifying and dissecting shared cognitive risk factors for LDs and ADHD has clinical relevance for assessment of comorbidity risk and for novel treatment targets that may impact generalized cognitive risk mechanisms.