Hand forces and placement are modulated and covary during anticipatory control of bimanual manipulation
Hand forces and placement are modulated and covary during anticipatory control of bimanual manipulation
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DOI：
10.1152/jn.00760.2018
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发表时间：
2019-06-01
影响因子：
2.5
通讯作者：
Gordon, Andrew M.
中科院分区：
文献类型：
--
作者：
Lee-Miller, Trevor;Santello, Marco;Gordon, Andrew M.
灵巧的物体操作依赖于动力学（力）和运动学（手形和手指位置）的前馈和反馈控制。举起质量分布不均匀的物体，涉及在物体升空时产生补偿力矩以抵消物体力矩。这是通过手指力量和位置的调制和共变来实现的，这已被证明是单手操作的一般特征。这些前馈预期过程发生在具体表现反馈之前。这种适应是单手灵巧操作独有的特征还是单手和双手操作的普遍特征尚不清楚。我们研究了补偿力矩的产生，通过手的位置和力调制，在双手操纵一个物体的变质心。参与者被指示在升降过程中防止物体滚动。类似于单手抓取，我们发现调制和协变的手的力量和位置成功的表现。因此，这种补偿力矩预期控制的运动适应是单手和双手效应器的普遍特征。我们的研究结果强调了操纵目标的高水平表征的参与，并强调了通过一系列效应器对物体操纵的连续力和位置调制来进行预期控制的感觉运动电路。据我们所知，这是第一次研究。通过调制和共变的手的力量和位置，以产生补偿力矩，成功地双手操纵具有不对称质心的物体。因此，数字力到位置调制是跨多个效应器的普遍现象，例如一只手的手指和两只手的手指。这增加了我们对将对象属性的低级内部表示集成到高级任务表示的理解。
Dexterous object manipulation relies on the feedforward and feedback control of kinetics (forces) and kinematics (hand shaping and digit placement). Lifting objects with an uneven mass distribution involves the generation of compensatory moments at object lift-off to counter object torques. This is accomplished through the modulation and covariation of digit forces and placement, which has been shown to be a general feature of unimanual manipulation. These feedforward anticipatory processes occur before performance-specific feedback. Whether this adaptation is a feature unique to unimanual dexterous manipulation or general across unimanual and bimanual manipulation is not known. We investigated the generation of compensatory moments through hand placement and force modulation during bimanual manipulation of an object with variable center of mass. Participants were instructed to prevent object roll during the lift. Similar to unimanual grasping, we found modulation and covariation of hand forces and placement for successful performance. Thus this motor adaptation of the anticipatory control of compensatory moment is a general feature across unimanual and bimanual effectors. Our results highlight the involvement of high-level representation of manipulation goals and underscore a sensorimotor circuitry for anticipatory control through a continuum of force and placement modulation of object manipulation across a range of effectors.NEW & NOTEWORTHY This is the first study, to our knowledge. to show that successful bimanual manipulation of objects with asymmetrical centers of mass is performed through the modulation and covariation of hand forces and placements to generate compensatory moments. Digit force-to-placement modulation is thus a general phenomenon across multiple effectors, such as the fingers of one hand, and both hands. This adds to our understanding of integrating low-level internal representations of object properties into high-level task representations.