University of Kansas, Lawrence, KS, USA.
Neuropsychology. 2012 May;26(3):357-67. doi: 10.1037/a0027972.
The principal cognitive domain impacted by multiple sclerosis (MS) appears to be information processing speed. Studies have documented mean differences between MS patients and healthy controls on numerous measures of information processing speed, but the present study is one of the first to examine individual variability (i.e., inconsistency) in processing speed.
Thirty-nine patients with relapsing-remitting or secondary progressive MS and 32 healthy controls completed a series of reaction time (RT) tests, the Stroop Test, and the Rey Auditory Verbal Learning Test. In addition to mean differences, appropriate measures of individual variability (i.e., coefficients of variability) were obtained for the tests yielding response times.
MS patients performed more poorly on all response time measures, responding more slowly and with greater inconsistency than controls. Logistic regression analyses showed that inconsistency measures contributed independently to the discrimination between groups beyond that resulting from measures of mean processing speed. The so-called "complexity effect" was also demonstrated; greater between-groups differences on both mean RTs and inconsistency generally occurred on tasks placing greater demand on central executive resources.
Processing speed in MS patients is characterized by greater individual variability as well as overall declines. This variability should be examined further in relation to neuroimaging indices of MS.
多发性硬化症（MS）主要影响的认知领域似乎是信息处理速度。许多研究记录了 MS 患者和健康对照者在信息处理速度的众多测量指标上的平均差异，但本研究是首次检查处理速度的个体变异性（即不一致性）。
39 名复发缓解型或继发进展型 MS 患者和 32 名健康对照者完成了一系列反应时（RT）测试、Stroop 测试和 Rey 听觉言语学习测试。除了平均差异外，还获得了产生反应时间的测试的个体变异性（即变异系数）的适当措施。
MS 患者在所有反应时测量中表现更差，反应速度更慢，一致性更高。逻辑回归分析表明，不一致性测量独立于平均处理速度测量的结果，有助于区分两组。还表现出所谓的“复杂性效应”；在对中央执行资源要求更高的任务上，组间平均 RT 和不一致性的差异通常更大。
MS 患者的处理速度的特点是个体变异性更大以及整体下降。应进一步研究这种变异性与 MS 的神经影像学指标的关系。
