Jo Hang Jin, Mattos Daniela, Lucassen Elisabeth B, Huang Xuemei, Latash Mark L
a Department of Kinesiology , The Pennsylvania State University, University Park.
b Department of Neurology , Pennsylvania State University-Milton S. Hershey Medical Center , Hershey.
J Mot Behav. 2017 Mar-Apr;49(2):218-228. doi: 10.1080/00222895.2016.1169986. Epub 2016 Aug 11.
The authors explored the changes in multidigit synergies in patients with multiple sclerosis (MS) within the framework of the uncontrolled manifold hypothesis. The specific hypotheses were that both synergy indices and anticipatory synergy adjustments prior to the initiation of a self-paced quick action would be diminished in the patients compared to age-matched controls. The MS patients and age-matched controls (n = 13 in both groups) performed one-finger and multifinger force production tasks involving both accurate steady-state force production and quick force pulses. The patients showed significantly lower maximal finger forces and a tendency toward slower force pulses. Enslaving was increased in MS, but only in the lateral fingers (index and little). Indices of multifinger synergies during steady-state force production were lower in MS, mainly due to the lower amount of intertrial variance that did not affect total force. Anticipatory synergy adjustments were significantly delayed in MS. The results show that MS leads to significant changes in multidigit synergies and feed-forward adjustments of the synergies prior to a quick action. The authors discuss possible contributions of subcortical structures to the impaired synergic control.
作者在非受控流形假设的框架内探讨了多发性硬化症（MS）患者多位数协同作用的变化。具体假设是，与年龄匹配的对照组相比，MS患者在自主快速动作开始前的协同指数和预期协同调整都会减弱。MS患者和年龄匹配的对照组（两组均为n = 13）进行了单指和多指力量产生任务，包括精确的稳态力量产生和快速力量脉冲。患者表现出明显较低的最大手指力量以及力量脉冲变慢的趋势。在MS中，协同作用增加，但仅在外侧手指（食指和小指）。在稳态力量产生过程中，MS患者的多指协同指数较低，主要是由于不影响总力量的试验间方差量较低。MS患者的预期协同调整明显延迟。结果表明，MS会导致多位数协同作用以及快速动作前协同作用的前馈调整发生显著变化。作者讨论了皮质下结构对协同控制受损可能产生的影响。
