Psychology Department, Montclair State University, 1 Normal Ave, Montclair, NJ 07043, USA.
Center for Neuropsychology and Neuroscience Research, Kessler Foundation, 120 Eagle Rock Ave, Suite 100, East Hanover, NJ 07936, USA.
Mult Scler Relat Disord. 2022 Jul;63:103890. doi: 10.1016/j.msard.2022.103890. Epub 2022 May 17.
The polyfactorial nature of the widely used symbol digit modalities test (SDMT) introduces significant measurement challenges in characterizing information processing speed (IPS) deficits in multiple sclerosis (MS). Measures with high psychometric IPS-specificity and less contamination from other cognitive domains are necessary to fully understand IPS changes.
Investigate how three mathematical modeling ex-Gaussian parameter estimates (mu, sigma, tau) derived from a simple response time (RT) task (1) differentiate MS from healthy control participants and (2) correspond to structural brain changes, to evaluate a novel IPS measurement approach.
Persons with and without MS completed a two-minute behavioral simple RT task, structural MRI and the MS functional composite. RT distributions were deconvolved into ex-Gaussian parameter estimates using mathematical modeling. Group differences and brain-behavior relationships were statistically evaluated.
Persons with MS experienced a general pattern of slowing as evidenced by a shift in the Gaussian (mu) component of the distribution. This correlated with whole brain volume and white matter specifically. Additionally, persons with MS had larger values of tau (elongated positively skewed tail) that may reflect attentional lapses.
The ex-Gaussian approach is sensitive to disease-related IPS changes and provides nuanced information about IPS slowing in MS.
广泛使用的符号数字模态测试（SDMT）的多因素性质在描述多发性硬化症（MS）中的信息处理速度（IPS）缺陷方面带来了重大的测量挑战。需要具有较高心理 IPS 特异性和较少受其他认知领域污染的测量方法，才能充分了解 IPS 的变化。
研究从简单反应时间（RT）任务中得出的三种数学建模外高斯参数估计（mu、sigma、tau）（1）如何区分 MS 患者和健康对照组，以及（2）与结构脑变化相对应，以评估一种新的 IPS 测量方法。
MS 患者和无 MS 患者完成了两分钟的行为简单 RT 任务、结构 MRI 和 MS 功能综合测试。使用数学建模对 RT 分布进行去卷积，得出外高斯参数估计。通过统计学评估组间差异和大脑-行为关系。
MS 患者表现出普遍的速度减慢模式，这表现在分布的高斯（mu）分量上的偏移。这与全脑体积和白质有关。此外，MS 患者的 tau 值较大（正偏态长尾拉长），这可能反映了注意力不集中。
外高斯方法对与疾病相关的 IPS 变化敏感，并提供有关 MS 中 IPS 减慢的细致信息。
