Department of Psychology, Washington State University, Pullman, WA, USA.
School of Electrical Engineering and Computer Science, Washington State University, Pullman, WA, USA.
Clin Neuropsychol. 2020 May;34(4):678-699. doi: 10.1080/13854046.2020.1733097. Epub 2020 Mar 19.
: In the real-world environment, multiple and interacting state-dependent factors (e.g., fatigue, distractions) can cause cognitive failures and negatively impact everyday activities. This study used ecological momentary assessment (EMA) and a n-back task to examine the relationship between fluctuating levels of cognition measured in the real-world environment and self-report and performance-based measures of functional status.: Thirty-five community-dwelling older adults ( age = 71.80) completed a brief battery of objective and self-report measures of cognitive and functional status. After completing 100, 45-second trials to reach stable performance on a n-back task, EMA data collection began. Four times daily for one week, participants received prompts on a tablet to complete a n-back task and a brief survey. From the EMA n-back trials, measures of EMA average performance and intra-individual variability (IIV) across performances were created.: For the EMA n-back, the correlation between IIV and EMA average was weak and non-significant. IIV associated with self-report measures, and EMA average with the objective, performance-based functional status composite. Hierarchical regressions further revealed that IIV was a significant predictor of self-reported functional status and cognitive failures over and above EMA average performance and global cognitive status. In contrast, for the objective, functional status composite, IIV did not explain additional variance.: The findings suggest that IIV and self-report measures of functional status and cognitive failures may capture a real-world cognitive capacity that fluctuates over time and with context; one that may not easily be captured by objective, performance-based measures designed to assess optimal function.
在真实环境中，多种相互作用的状态依赖因素（例如疲劳、分心）可能导致认知失败，并对日常活动产生负面影响。本研究使用生态瞬时评估（EMA）和 n 回任务来考察在真实环境中测量的波动认知水平与自我报告和基于表现的功能状态测量之间的关系。
三十五名居住在社区的老年人（年龄=71.80）完成了一套简短的客观和自我报告认知和功能状态测量。在完成 100 次 45 秒的 n 回任务，达到稳定表现后，开始进行 EMA 数据收集。在一周的四天里，参与者每天四次在平板电脑上收到提示，完成 n 回任务和简短调查。从 EMA n 回试验中，创建了 EMA 平均表现和个体内变异性（IIV）的测量值。
对于 EMA n 回，IIV 与 EMA 平均值之间的相关性较弱且不显著。IIV 与自我报告测量相关，而 EMA 平均值与客观、基于表现的功能状态综合指标相关。层次回归进一步表明，IIV 是自我报告功能状态和认知失败的重要预测因素，超过了 EMA 平均表现和整体认知状态。相比之下，对于客观的功能状态综合指标，IIV 并不能解释额外的方差。
研究结果表明，IIV 和自我报告的功能状态和认知失败测量可能捕捉到一种随时间和环境波动的真实世界认知能力；这种能力可能不容易被旨在评估最佳功能的客观、基于表现的测量方法所捕捉。
