Studies on goal-directed arm movements have shown a close link between feedforward and feedback control in protocols where both planning and online control processes faced a similar type of perturbation, either mechanical or visual. This particular context might have facilitated the use of an adapted internal model by feedforward and feedback control. Here we considered this link in a context where after feedforward control was adapted through proprioception-based processes, feedback control was tested under visual perturbation. We analyzed the response of the reaching hand to target displacements following adaptation to an altered force field induced by rotating participants at constant velocity. Reaching corrections were assessed through variables related to the accuracy (lateral and longitudinal endpoint errors) and kinematics (movement time, peak velocity) of the corrective movements. The electromyographic activity of different arm muscles (pectoralis, deltoid, biceps and triceps brachii) was analyzed. Statistical analyses revealed that accuracy and kinematics of corrective movements were strikingly alike between normal and altered gravitoinertial force fields. However, pectoralis and biceps muscle activities recorded during corrective movements were significantly modified to counteract the effect of rotation-induced Coriolis and centrifugal forces on the arm. Remarkably, feedback control was functional from the very first time participants encountered a target jump in the altered force field. Overall, the present results demonstrate that feedforward control enables immediate functional feedback control even when applied to distinct sensorimotor processes.

中文翻译：

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改变重力惯性力场中目标跳跃后的在线校正响应指向嵌套前馈和反馈控制

对目标导向的手臂运动的研究表明，在计划和在线控制过程都面临类似机械或视觉扰动的协议中，前馈和反馈控制之间存在密切联系。这种特殊的背景可能有助于通过前馈和反馈控制使用经过调整的内部模型。在这里，我们在通过基于本体的过程调整前馈控制后，在视觉扰动下测试反馈控制的上下文中考虑了这个链接。我们分析了在适应由以恒定速度旋转的参与者引起的改变的力场之后，伸手对目标位移的响应。通过与精度（横向和纵向终点误差）和运动学（运动时间、矫正运动的峰值速度）。分析了不同手臂肌肉（胸肌、三角肌、二头肌和肱三头肌）的肌电活动。统计分析表明，正常和改变的重力惯性力场之间的校正运动的准确性和运动学惊人地相似。然而，在矫正运动期间记录的胸肌和二头肌活动被显着修改，以抵消旋转引起的科里奥利力和离心力对手臂的影响。值得注意的是，从参与者第一次在改变的力场中遇到目标跳跃开始，反馈控制就起作用了。总体而言，目前的结果表明，即使应用于不同的感觉运动过程，前馈控制也能实现即时的功能反馈控制。