Characteristics and Correlates of Intraindividual Variability in Executive Control Processes

大多数科学研究关注的是平均表现（A组相对于B组完成任务的速度有多快）。不幸的是，这种对平均表现的关注在很大程度上掩盖了对表现变异性的研究，例如在一系列试验中，给定个体的反应速度或速度的波动。认知神经科学、神经心理学和数学建模等多个科学学科的共识不断增加，表明认知功能在理论上有趣的方面并不能被平均群体表现所捕获。此外，强有力的主张，依赖平均性能估计可能反映了一个关键的过度简化的行为模式。执行功能的测量反映了我们关注重要信息或抑制无关细节的能力，特别适合评估变异性。最近的研究结果表明，整个响应延迟试验的性能波动是明显的执行措施，增加更困难的任务条件下，并与大脑结构与高效的执行过程。尽管人们对跨学科的可变性越来越感兴趣，但关键问题仍然存在。为了进一步理解绩效变异的本质、潜在机制和相关因素，本研究计划将探讨三个关键的研究目标，包括：（1）直接比较认知变量的变异性的竞争定义，（执行功能）、生理（步态）和大脑（血氧水平依赖性或BOLD反应）功能;（2）检查各种变异性指标变化之间的关联（认知功能的波动与大脑激活模式的波动有关吗？）以及其他指标（压力、大脑结构和功能）的变化，在短期（试验到试验）和长期（年到年）随访间隔中;以及（3）通过评估或操纵关键因素（如认知训练和认知负荷）来识别潜在的变化过程。

Most scientific research focuses on average performance (how much faster does group A perform a task relative to Group B). Unfortunately, this focus on mean performance has largely overshadowed research on variability in performance, such as the fluctuations in how fast or slow a given individual responds across a series of trials. Growing consensus from various scientific disciplines, including cognitive neuroscience, neuropsychology, and mathematical modeling, suggests that theoretically interesting aspects of cognitive function are not captured by mean group performance. Moreover, strong claims are made that reliance on mean performance estimates may reflect a critical oversimplification of behavior patterns. Measures of executive function, reflecting our ability to attend to important information or inhibit irrelevant detail, are particularly well suited for assessing variability. Recent findings have shown that performance fluctuations across response latency trials are pronounced for executive measures, increase under more difficult task conditions, and are associated with brain structures linked to efficient executive processes. Despite growing interest in variability across disciplines, key questions endure. To further our understanding of the nature, underlying mechanisms, and correlates of performance variability, this research program will examine three key research objectives including: (1) the direct comparison of competing definitions of variability for measures of cognitive (executive function), physiological (gait), and brain (blood oxygen level dependent or BOLD response) function; (2) the examination of associations among changes in the various indices of variability (are fluctuations in cognitive functioning linked to fluctuations in brain activation patterns?), as well as change in other indicators (stress, brain structure and function), across short-term (trial-to-trial) and long-term (year-to-year) follow-up intervals; and (3) the identification of potential processes underlying increased variability by assessing or manipulating key factors such as cognitive training and cognitive load.