Behavior Genetic Analyses of Executive Functions

儿童发育行为遗传学研究进展 认知能力侧重于传统的心理测量评估，而不是 而不是认知心理学中当前感兴趣的领域和过程。一 这样的领域是对特定认知过程的控制和协调 在执行复杂任务的过程中。这些假定的执行功能 是神经学上与额叶相关的通用控制机制 脑叶活动，调节各种认知子过程的操作 从而调节人类认知的动态。当前的目标是 建议进行首个个体行为遗传学研究 具有遗传信息的双胞胎样本中执行功能的差异 已经具有一般的和特定的认知能力。我们会 重点关注行政职能的三个最受支持的组成部分：转移 心理定势(转移)、工作记忆的监测和更新 表征(‘更新’)和优先反应的抑制 (‘抑制’)以及使用最广泛的‘额叶’或执行 任务。拟议的研究将：(1)在样本中确认(或拒绝)来自 表现出全正常范围智商、表型的普通人群 执行功能成分与任务的相关及因素结构 以前在选定的样本中观察到的；(2)评估遗传和 对执行职能组成部分和任务的环境贡献； 估计每种生物的遗传和环境变异 它们之间的遗传和环境影响的相关性；(3)确定， 通过多变量遗传和环境验证性事实分析， 执行功能的个体差异是否反映了共同的遗传或 跨组件和任务的环境因素，或者，或者，表现为 组件或任务的高度专用性；以及(4)确定以下方面的程度 执行功能上的哪些个体差异是遗传的或 环境独立于传统的智力概念化。 我们将测试172对同卵双胞胎和150对异卵双胞胎中的644对双胞胎 帕斯，他们自那以来一直参与科罗拉多州纵向双胞胎研究 婴儿期。这些受试者将在17岁时接受三项指数测试 执行功能的三个组成部分中的每一个，都被广泛使用 执行职能任务(威斯康星卡分类测试、操作范围 测试和河内塔)，以及两个流体智力测试(瑞文的 累进矩阵检验和卡特尔文化公平检验)。数据将是 进行验证性因子分析和多变量表型分析 然后通过遗传和环境结构方程分析来解决这四个问题 明确的目标。

Previous research in developmental behavioral genetics of cognitive abilities has focused on traditional psychometric assessments rather than domains and processes of current interest in cognitive psychology. One such domain is the control and coordination of specific cognitive processes during the performance of complex tasks. These postulated executive functions are general-purpose control mechanisms, neurologically associated with frontal lobe activity, that modulate the operation of various cognitive subprocesses and thereby regulate the dynamics of human cognition. The goal of the present proposal is to conduct the first behavioral genetic study of individual differences in executive functions in a genetically informative twin sample already characterized for general and specific cognitive abilities. We will focus on the three best supported components of executive function: shifting of mental sets ('Shifting'), monitoring and updating of working memory representations ('Updating'), and inhibition of prepotent responses ('Inhibition') as well as the most widely used 'frontal lobe' or executive tasks. The proposed research will: (1) Confirm (or reject), in a sample from the general population showing a full normal range of IQ, the phenotypic correlations and factor structure for executive function components and tasks previously observed in selected samples; (2) assess the genetic and environmental contributions to executive function components and tasks, estimating both the heritable and environmental variance of each and the genetic and environmentally influenced correlations among them; (3) determine, through multivariate genetic and environmental confirmatory facto analyses, whether individual differences in executive functions reflect common genetic or environmental factors across components and tasks or, alternatively, manifest a high degree of component or task specificity; and (4) determine the extent to which individual differences in executive functions are genetically or environmentally independent of traditional conceptualizations of intelligence. We will test 644 individual twins, from 172 monozygotic and 150 dizygotic pairs, who have participated in the Colorado Longitudinal Twin Study since infancy. These subjects will be tested at age 17 years on three index tests of each of the three components of executive functioning, three widely used executive function tasks (the Wisconsin Card Sort Test, the Operations Span test, and the Tower of Hanoi), and two tests of fluid intelligence (Raven's Progressive Matrices Test and Cattell's Culture Fair Test). Data will be subjected to confirmatory factor analyses multivariate phenotypic analyses, and then genetic and environmental structural equation analyses to address the four specific aims.