Shim Jae Kun, Latash Mark L, Zatsiorsky Vladimir M
Department of Kinesiology, Pennsylvania State University, Rec. Hall-267, University Park, PA 16802, USA.
Neurosci Lett. 2003 Dec 15;353(1):72-4. doi: 10.1016/j.neulet.2003.08.079.
We studied how the central nervous system (CNS) organizes outputs of effectors in a redundant motor task. During four-finger ramp force production, finger forces show positive covariations across trials at low forces, which turn into negative covariations at a critical force value (F(CR)). Subjects performed such tasks with different target amplitudes and durations of the ramp. F(CR) showed significant linear relations to the rate of force change. The slopes of the relations varied across subjects corresponding to a critical time (T(CR)) ranging from 0.13 to 0.84 s. Across subjects, T(CR) showed no relation to maximal force production; T(CR) increased with the ramp duration. We conclude that the CNS needs a certain time to organize stabilization of total force by a negative covariation among finger forces.
我们研究了中枢神经系统（CNS）如何在冗余运动任务中组织效应器的输出。在四指斜坡力产生过程中，在低力时手指力在各次试验间呈现正协变，而在临界力值（F(CR)）时变为负协变。受试者以不同的目标幅度和斜坡持续时间执行此类任务。F(CR)与力变化率呈现显著的线性关系。这些关系的斜率因受试者而异，对应于0.13至0.84秒的临界时间（T(CR)）。在所有受试者中，T(CR)与最大力产生无关；T(CR)随斜坡持续时间增加。我们得出结论，中枢神经系统需要一定时间通过手指力之间的负协变来组织总力的稳定。
