Department of Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, MI 48109, United States.
J Neurosci Methods. 2011 Apr 30;197(2):270-3. doi: 10.1016/j.jneumeth.2011.03.005. Epub 2011 Mar 23.
The primary purpose of this study was to use functional principal component analysis (FPCA) to analyze Hoffman-reflex (H-reflex) recruitment curves. Smoothed and interpolated recruitment curves from 38 participants were used for analysis. Standard methods were used to calculate three discrete variables (i.e., H(max)/M(max) ratio, H(th), H(slp)). FPCA was then used to extract principal component functions (PCFs) from the processed recruitment curves. PCF scores were calculated to determine how much each PCF contributed to an individuals' recruitment curve. The analysis extracted three PCFs, and three sets of PCF scores. Correlation analyses and systematic variation in the PCF scores indicated that the scores for the first PCF were primarily correlated to H-reflex threshold (H(th)) and that the scores for the second and third PCFs were correlated to H-reflex magnitude (H(max)/M(max) ratio) and slope (H(slp)), respectively. In addition, results from the FPCA indicated that the first PCF explained 56.0% of the variance between all H-reflex recruitment curves, whereas the second and third PCFs explained 24.1% and 13.0%, respectively. The high correlations indicate FPCA-derived PCFs capture similar physiological information as the standard discrete variables and suggest that application of FPCA to H-reflex recruitment curves could be used in future studies to complement traditional analyses that investigate excitability of the motoneuron pool.
本研究的主要目的是使用功能主成分分析(FPCA)来分析 Hoffmann 反射(H 反射)募集曲线。分析使用了 38 名参与者的平滑和插值募集曲线。采用标准方法计算了三个离散变量(即 H(max)/M(max) 比、H(th)、H(slp))。然后使用 FPCA 从处理后的募集曲线中提取主成分函数(PCF)。计算 PCF 得分以确定每个 PCF 对个体募集曲线的贡献程度。该分析提取了三个 PCF,并得到了三组 PCF 得分。相关性分析和 PCF 得分的系统变化表明,第一 PCF 的得分主要与 H 反射阈值(H(th))相关,而第二和第三 PCF 的得分与 H 反射幅度(H(max)/M(max) 比)和斜率(H(slp))相关。此外,FPCA 的结果表明,第一 PCF 解释了所有 H 反射募集曲线之间方差的 56.0%,而第二和第三 PCF 分别解释了 24.1%和 13.0%。高相关性表明,FPCA 衍生的 PCF 捕获了与标准离散变量相似的生理信息,并表明 FPCA 可应用于 H 反射募集曲线,以补充研究运动神经元池兴奋性的传统分析。