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条件相关的认知障碍的一个因素。然而，目前尚不清楚被假设为反映执行过程的变量是否代表了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，以及年龄对不同认知变量的影响在多大程度上可能受到执行过程的年龄相关影响的中介。这些问题将在一系列研究中进行调查，样本涉及100至250名年龄在18岁至大约80岁之间的健康成年人。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)，每个年轻人和老年参与者都执行三项假设任务来评估每个执行过程方面。这些研究的目的是检验假设代表执行过程的同一方面的三个变量彼此相关的程度，从而可能代表个体差异的单一维度，并调查执行过程变量在两次实践中相关性模式和可靠性的可能变化。该项目的最后一项研究将涉及大约250名年龄在18岁到80岁之间的健康成年人，他们将执行一系列任务，这些任务旨在评估执行过程的不同方面，以及其他类型的认知功能，如知觉速度和工作记忆。各种基于相关性的分析，包括结构方程模型，将被用来评估关于执行过程的单一性或多重性、执行过程变量与代表其他类型认知的变量的关系以及年龄相关影响对执行过程变量的影响的水平(即，个别变量特有的或许多变量共同的)的假设的合理性。

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.