Tokyo Institute of Technology, Institute of Innovative Research, Yokohama 226-8503, Japan
Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan.
eNeuro. 2019 Jul 25;6(4). doi: 10.1523/ENEURO.0095-19.2019. Print 2019 Jul/Aug.
Grasping is an action engraved in the human genome, enabling newborn infants to hang from a monkey-bar immediately after birth. The grasp force provides rich information about the brain's control of arm movements. In this study, we tested the hypothesis that the grasp force increases to improve the hand's movement precision during reaching. In two reaching experiments, subjects increased grasp force to suppress movement imprecision that arose from both self-generated motor noise and from an unpredictable environment. Furthermore, the grasp force did not increase constantly, but increased specifically along the movement where the hand's deviation was greatest. The increased grasp was premeditated and was not a reaction to environmental forces, suggesting that the central nervous system has a predictive, state-dependent model of movement precision during reaching. The grasp force provides a high temporal resolution and calibration-less estimate of movement precision adaptation.
抓握是人类基因组中固有的动作，使新生儿在出生后立即能够悬挂在单杠上。抓握力提供了有关大脑控制手臂运动的丰富信息。在这项研究中，我们检验了以下假设，即抓握力的增加可以提高伸手过程中手部运动的精度。在两个伸手实验中，被试增加抓握力以抑制由自身产生的运动噪声和不可预测的环境引起的运动不准确性。此外，抓握力并非持续增加，而是仅沿手部偏差最大的运动方向增加。增加的抓握力是有预谋的，而不是对环境力的反应，这表明中枢神经系统在伸手过程中对运动精度具有预测性、状态相关的模型。抓握力提供了运动精度适应性的高时间分辨率和无校准估计。
