Crevecoeur F, Gevers M
Institute of Information and Communication Technologies, Electronics and Applied Mathematics, University of Louvain, Louvain-la-Neuve 1348, Belgium, and Institute of Neuroscience, University of Louvain, Brussels 1200, Belgium
Institute of Information and Communication Technologies, Electronics and Applied Mathematics, University of Louvain, Louvain-la-Neuve 1348, Belgium
Neural Comput. 2019 Apr;31(4):738-764. doi: 10.1162/neco_a_01170. Epub 2019 Feb 14.
Compensating for sensorimotor noise and for temporal delays has been identified as a major function of the nervous system. Although these aspects have often been described separately in the frameworks of optimal cue combination or motor prediction during movement planning, control-theoretic models suggest that these two operations are performed simultaneously, and mounting evidence supports that motor commands are based on sensory predictions rather than sensory states. In this letter, we study the benefit of state estimation for predictive sensorimotor control. More precisely, we combine explicit compensation for sensorimotor delays and optimal estimation derived in the context of Kalman filtering. We show, based on simulations of human-inspired eye and arm movements, that filtering sensory predictions improves the stability margin of the system against prediction errors due to low-dimensional predictions or to errors in the delay estimate. These simulations also highlight that prediction errors qualitatively account for a broad variety of movement disorders typically associated with cerebellar dysfunctions. We suggest that adaptive filtering in cerebellum, instead of often-assumed feedforward predictions, may achieve simple compensation for sensorimotor delays and support stable closed-loop control of movements.
补偿感觉运动噪声和时间延迟已被确定为神经系统的一项主要功能。尽管在运动规划过程中的最优线索组合或运动预测框架中，这些方面常常被分别描述，但控制理论模型表明，这两种操作是同时进行的，而且越来越多的证据支持运动指令基于感觉预测而非感觉状态。在这封信中，我们研究状态估计对预测性感觉运动控制的益处。更确切地说，我们将对感觉运动延迟的显式补偿与在卡尔曼滤波背景下得出的最优估计相结合。基于对受人类启发的眼睛和手臂运动的模拟，我们表明，对感觉预测进行滤波可提高系统针对由于低维预测或延迟估计误差导致的预测误差的稳定裕度。这些模拟还突出表明，预测误差在定性上可解释通常与小脑功能障碍相关的多种运动障碍。我们认为，小脑的自适应滤波而非通常假定的前馈预测，可能实现对感觉运动延迟的简单补偿，并支持运动的稳定闭环控制。
