Finger interaction in a three-dimensional pressing task.
Finger interaction in a three-dimensional pressing task.
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DOI：
10.1007/s00221-010-2213-7
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发表时间：
2010-05
影响因子：
2
通讯作者：
Latash, Mark L.
中科院分区：
文献类型：
--
作者：
Kapur, Shweta;Friedman, Jason;Zatsiorsky, Vladimir M.;Latash, Mark L.
精确控制手指产生的力对于执行对象操作是必不可少的。本研究探讨了手指互动时，准确的时间曲线的力产生在不同的方向，而使用的手指或所有四个手指的手。我们假设，剪切力分量之间的非预期力产生的模式可能涉及在垂直力产生的早期研究中未观察到的功能。特别是，我们期望看到非任务手指产生的非预期力不是在指令力的方向上，而是在相反的方向上，以及在与指令方向正交的方向上产生大量的力。我们还测试了一个假设，即使用不受控制的流形假设框架量化的多指协同作用将有助于减少总力大小和方向的跨试验方差。年轻、健康的受试者被要求通过用右手（优势手）的手指按压力传感器，在五个不同方向上产生精确的力梯度。食指在非任务手指中引起最小的非预期力。当小指是非任务手指时，小指显示出最小的非预期力。任务手指在与预期力方向正交的方向上显示出大量的力产生。在四指任务中，单个力矢量通常指向任务方向，这些偏差几乎完美地匹配以在任务方向上产生合力。多指协同指数反映了手指模式（命令手指）的空间中的强共变，这降低了试验中总力大小和方向的变异性。协同作用指数在试验时间的前30%内增加，然后保持在几乎恒定的水平。与向下的压力分量相比，剪切力分量的总力大小稳定的协同指数更高。结果表明奴役和协同力调整之间的复杂相互作用，可能反映了日常任务的经验。该数据首次记录了多指协同作用，稳定了剪切力大小和力矢量方向。这些协同作用可能在物体操纵期间稳定手部动作方面发挥重要作用。
Accurate control of forces produced by the fingers is essential for performing object manipulation. This study examines the indices of finger interaction when accurate time profiles of force are produced in different directions, while using one of the fingers or all four fingers of the hand. We hypothesized that patterns of unintended force production among shear force components may involve features not observed in the earlier studies of vertical force production. In particular, we expected to see unintended forces generated by non-task fingers not in the direction on the instructed force but in the opposite direction as well as substantial force production in directions orthogonal to the instructed direction. We also tested a hypothesis that multi-finger synergies, quantified using the framework of the uncontrolled manifold hypothesis, will help reduce across-trials variance of both total force magnitude and direction. Young, healthy subjects were required to produce accurate ramps of force in five different directions by pressing on force sensors with the fingers of the right (dominant) hand. The index finger induced the smallest unintended forces in non-task fingers. The little finger showed the smallest unintended forces when it was a non-task finger. Task fingers showed substantial force production in directions orthogonal to the intended force direction. During four-finger tasks, individual force vectors typically pointed off the task direction, with these deviations nearly perfectly matched to produce a resultant force in the task direction. Multi-finger synergy indices reflected strong co-variation in the space of finger modes (commands to fingers) that reduced variability of the total force magnitude and direction across trials. The synergy indices increased in magnitude over the first 30% of the trial time and then stayed at a nearly constant level. The synergy index for stabilization of total force magnitude was higher for shear force components as compared to the downward pressing force component. The results suggest complex interactions between enslaving and synergic force adjustments, possibly reflecting the experience with everyday prehensile tasks. For the first time, the data document multi-finger synergies stabilizing both shear force magnitude and force vector direction. These synergies may play a major role in stabilizing the hand action during object manipulation.
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影响因子：
2
作者：
Ingram, James N.;Kording, Konrad P.;Howard, Ian S.;Wolpert, Daniel M.
通讯作者：
Wolpert, Daniel M.
影响因子：
2.1
作者：
Kim, Sun Wook;Shim, Jae Kun;Latash, Mark L.
通讯作者：
Latash, Mark L.
DOI：
10.1007/978-0-387-77064-2_31
发表时间：
2009-01-01
期刊：
PROGRESS IN MOTOR CONTROL: A MULTIDISCIPLINARY PERSPECTIVE
影响因子：
--
作者：
Johnston, Jamie A.;Winges, Sara A.;Santello, Marco
通讯作者：
Santello, Marco
影响因子：
2.4
作者：
LEIJNSE, JNAL;SNIJDERS, CJ;HOVIUS, SER
通讯作者：
HOVIUS, SER
影响因子：
2
作者：
Gao, F;Latash, ML;Zatsiorsky, VM
通讯作者：
Zatsiorsky, VM