Advancing the understanding of fundamental principles of motor control.

提出的理论驱动的研究计划是建立在我们在以前的NSERC资助任期内的早期成就之上的（见Feldman 2015，书）：(1)起源于初级运动皮层（M1）的皮质脊髓（CS）系统以前馈方式设置和重置适当肌肉开始募集的身体部分的阈值（参考）位置（Raptis等人，2010；Ilmane等人，2013；Zhang等人，2017）；(2) CS通路介导的阈值位置控制是预期行为的基础（Turpin et al. 2016; Zhang et al. 2017）；(3)该理论已被推广并验证为人类的伸手、跳跃、行走和猴子的头部运动（Feldman 2015）；(4)进一步扩展到考虑高级脑功能？M1神经元定向调谐的起源（Feldman，特邀评论，附录）和感知，并解释幻肢现象和视觉空间恒常性（Feldman 2016）。该计划的长期目标是进一步推进对运动动作控制的基本原理的理解。第一个具体目标是测试假设，即通过改变肌肉激活的空间阈值，神经系统将平衡和稳定从一个地方转移到另一个地方。通过这样做，系统可以引出一个单一的步骤，并以期望的速度连续运动。作为对瞬态扰动的响应，系统可能被迫暂时降低参照身体位置的移动速率，从而使整个步态模式及时移动，这种现象称为持久（“永久”）相位重置。我们将测试前庭、皮质脊髓和/或视觉系统是否负责这种相位重置，从而参与步态速度的控制。测试将分别通过应用经颅磁刺激（TMS）、前庭电刺激（GVS）或视觉扰动来完成。第二个具体目标是测试同侧CS束在单手和双手运动中控制空间阈值的作用，这将有助于推动理论超越目前的观点，从而满足长期目标。这个项目的独特之处在于，它代表了进一步发展和测试经验（非计算）阈值位置控制理论的前沿研究，与电机控制的替代计算理论相比，希望它们之间的争议最终得到解决。这个多学科的项目将有利于HQP的培训，因为它对理解生物运动是如何被控制有很大的帮助。这个项目的应用方面也很重要，正如我们的团队通过精心设计一种用于识别中风后痉挛的设备（专利）和通过使用参考控制的生理原理来改善机器人的类人运动（例如Bicchi等人，2002年）所证明的那样。

The proposed theory-driven research program is built on our earlier achievements under the tenure of previous NSERC grants (see Feldman 2015, book): (1) The corticospinal (CS) system originating from the primary motor cortex (M1) sets and resets, in a feedforward way, the threshold (referent) position of body segments at which appropriate muscles begin to be recruited (Raptis et al. 2010; Ilmane et al. 2013; Zhang et al. 2017); (2) Threshold position control mediated by CS pathways underlies anticipatory actions (Turpin et al. 2016; Zhang et al. 2017); (3) The theory has been generalized and validated for reaching, jumping, walking in humans and head motion in monkeys (Feldman 2015); (4) It was further extended to consider higher brain functions ? the origin of directional tuning of M1 neurons (Feldman, invited review, appended) and perception, with explanations of the phantom limb phenomenon and visual space constancy (Feldman 2016). The long-term objective of the program is to further advance understanding of basic principles underlying the control of motor actions. The first specific objective is to test the hypothesis that by shifting spatial thresholds for muscle activation, the nervous system transfers balance and stability from one place to another. By doing so, the system can elicit a single step and continuous locomotion at a desired speed. In response to a transient perturbation, the system may be forced to temporarily decrease the rate of shifts in the referent body location such that the whole gait pattern will be shifted in time, a phenomenon called long-lasting (“permanent”) phase resetting. We will test whether vestibular, corticospinal and/or visual systems are responsible for such phase resetting and thus involved in the control of gait speed. Testing will be done by applying Transcranial Magnetic stimulation (TMS), Galvanic Vestibular Stimulation (GVS) or visual perturbations, respectively. The second specific objective is to test the role of the ipsilateral CS tract in the control of spatial thresholds during uni- and bi-manual movements, which will help advance the theory beyond its present point, thus meeting the long-term objective. The uniqueness of this program is that it represents cutting-edge research in the further development and testing of the empirical (non-computational) threshold position control theory in comparison to the alternative, computational theory of motor control in the hope that the controversy between them will eventually be resolved. This multidisciplinary program will benefit the training of HQP by substantially contributing to the understanding of how biological movements are controlled. The applied aspect of this program can also be significant as has been demonstrated by our team by elaborating a device for identification of post-stroke spasticity (patented) and by the use of the physiological principles of referent control in improving human-like motions of robots (e.g. Bicchi et al. 2002).