Effects of Aging on Executive Processes

执行过程经常被认为是导致与年龄相关的认知缺陷以及与各种不同疾病和神经病理状况相关的认知障碍的因素。 然而，目前尚不清楚假设反映执行过程的变量是否代表个体差异的单一维度，执行过程是否以及如何与其他类型的认知变量相关，以及对不同认知变量的年龄相关影响在多大程度上可能由对执行过程的年龄相关影响介导。 这些问题将在一系列研究中进行调查，涉及100至250名18至80岁的健康成年人的样本。最初的年龄比较研究将集中在执行过程的四个方面（即，更新，分时，和规划），与每个年轻和年老的成年参与者执行三个任务假设评估每个执行过程方面。 这些研究的目标是检查的程度，假设代表同一方面的执行过程的三个变量是相互关联的，因此可能代表一个单一的维度的个体差异，并调查可能的变化模式的相关性，和可靠性的执行过程变量，在两个会话的做法。 该项目的最终研究将涉及约250名年龄在18至80岁之间的健康成年人，他们将执行一系列任务，旨在评估执行过程的不同方面和其他类型的认知功能，如感知速度和工作记忆。 各种基于相关性的分析，包括结构方程模型，将用于评估关于执行过程的单一或多重性质的假设的可接受性，执行过程变量与代表其他类型认知的变量的关系，以及水平（即，具体到个别变量或共同的许多变量），在年龄相关的影响作用于执行过程变量。

Executive processes are frequently implicated as a factor contributing to age-related cognitive deficits, and to cognitive impairments associated with a variety of different diseases and neuropathological conditions. However, it is not yet known whether variables hypothesized to reflect executive processes represent a unitary dimension of individual differences, if and how executive processes are related to other types of cognitive variables, and to what extent age-related effects on different cognitive variables may be mediated by age- related effects on executive processes. These issues will be investigated in a series of studies involving samples of between 100 and 250 healthy adults between 18 and approximately 80 years of age. The initial age-comparative studies will focus on four aspects of executive processes (i.e., updating, time-sharing, and planning), with each young and old adult participant performing three tasks hypothesized to assess each executive process aspect. The goals of these studies are to examine the degree to which the three variables postulated to represent the same aspect of executive processes are correlated with one another, and hence may represent a unitary dimension of individual differences, and to investigate possible changes in the pattern of correlations, and reliabilities of the executive process variables, across two sessions of practice. The final study in the project will involve a total of about 250 healthy adults ranging from 18 to 80 years of age who will perform a battery of tasks designed to assess different aspects of executive processes and other types of cognitive functioning such as perceptual speed and working memory. A variety of correlation-based analyses, including structural equation models, will be used to evaluate the plausibility of hypotheses regarding the unitary or multiple nature of executive processes, relations of executive process variables to variables representing other types of cognition, and the level (i.e., specific to individual variables or common to many variables) at which age-related influences operate on executive process variables.