1Rotman Research Institute,Baycrest,Toronto,Canada.
J Int Neuropsychol Soc. 2018 May;24(5):456-465. doi: 10.1017/S1355617717001266. Epub 2017 Dec 6.
Intraindividual variability increases with age, but the relative strength of association with cognitive domains is still unclear. The objective of this study was to examine the relation between cognitive domains and the shape and spread of response time (RT) distributions as indexed by intraindividual standard deviation (ISD), and ex-Gaussian parameters (μ, σ, τ).
Healthy adults (40 young [aged 18-30 years], 40 young-old [aged 65-74 years], and 41 old-old [aged 75-85 years]) completed neuropsychological testing and a touch-screen attention task from which ISD and ex-Gaussian parameters were derived. The relation between RT performance and cognitive domains (memory, processing speed, executive functioning) was examined with structural equation modeling (SEM), and the predictive power of RT distribution indices over age was investigated with linear regression.
ISD, μ, and τ, but not σ, showed a linear increase with age group. An SEM showed that independent of age, τ was most strongly associated with executive functioning, while μ exhibited less critical associations. Linear regression indicated that μ and τ explained a significant portion of variance in processing speed and executive ability in addition to age group. Memory was more parsimoniously predicted by age, without any significant contribution of ex-Gaussian parameters.
The findings suggest that exceptionally slow responses convey attention lapses through wavering of cognitive control, which strongly correspond to executive functioning tests. General slowing and extremely slow responses predicted processing speed and executive performance beyond age group, indicating that RT metrics are sensitive to differences in cognitive ability. (JINS, 2018, 24, 456-465).
个体内变异性随年龄增长而增加，但与认知领域的关联相对强度仍不清楚。本研究的目的是检验认知领域与反应时（RT）分布的形态和分布之间的关系，其指标为个体内标准差（ISD）和超伽马分布参数（μ、σ、τ）。
健康成年人（40 名年轻人[年龄 18-30 岁]、40 名年轻老年人[年龄 65-74 岁]和 41 名老年人[年龄 75-85 岁]）完成神经心理学测试和触摸屏注意任务，从中得出 ISD 和超伽马分布参数。使用结构方程模型（SEM）检验 RT 表现与认知领域（记忆、处理速度、执行功能）之间的关系，并使用线性回归研究 RT 分布指数对年龄的预测能力。
ISD、μ和τ随年龄组呈线性增加，而σ则没有。SEM 显示，独立于年龄，τ与执行功能的关联最强，而μ的关联则不太关键。线性回归表明，μ和τ除了年龄组外，还可以解释处理速度和执行能力的大部分方差。记忆可以通过年龄更简洁地预测，而超伽马参数没有任何显著贡献。
这些发现表明，异常缓慢的反应通过认知控制的波动传达注意力不集中，这与执行功能测试密切相关。总体减速和极其缓慢的反应预测了处理速度和执行表现，超出了年龄组的范围，表明 RT 指标对认知能力的差异很敏感。（JINS，2018，24，456-465）。
