Cluff Tyler, Crevecoeur Frédéric, Scott Stephen H
Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada.
Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada; Dept. of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada; Dept. of Medicine, Queen's University, Kingston, ON, Canada.
Vision Res. 2015 May;110(Pt B):215-22. doi: 10.1016/j.visres.2014.06.011. Epub 2014 Jul 9.
In order to perform accurate movements, the nervous system must transform sensory feedback into motor commands that compensate for errors caused by motor variability and external disturbances. Recent studies focusing on the importance of sensory feedback in motor control have illustrated that the brain generates highly flexible responses to visual perturbations (hand-cursor or target jumps), or following mechanical loads applied to the limb. These parallel approaches have emphasized sophisticated, goal-directed feedback control, but also reveal that flexible perturbation responses are expressed at different latencies depending on what sensory system is engaged by the perturbation. Across studies, goal-directed visuomotor responses consistently emerge in muscle activity ∼100ms after a perturbation, while mechanical perturbations evoke goal-directed muscle responses in as little as ∼60ms (long-latency responses). We discuss the limitation of current models of multisensory integration in light of these asynchronous processing delays, and suggest that understanding how the brain performs real-time multisensory integration is an open question for future studies.
为了执行精确的动作，神经系统必须将感觉反馈转化为运动指令，以补偿由运动变异性和外部干扰引起的误差。最近关注感觉反馈在运动控制中重要性的研究表明，大脑会对视觉扰动（手部光标或目标跳跃）或肢体受到机械负荷后产生高度灵活的反应。这些并行的研究方法强调了复杂的、目标导向的反馈控制，但也揭示了灵活的扰动反应会根据扰动所涉及的感觉系统不同而在不同潜伏期表现出来。在各项研究中，目标导向的视觉运动反应在扰动后约100毫秒的肌肉活动中持续出现，而机械扰动在短短约60毫秒内就会引发目标导向的肌肉反应（长潜伏期反应）。鉴于这些异步处理延迟，我们讨论了当前多感觉整合模型的局限性，并指出了解大脑如何进行实时多感觉整合是未来研究的一个开放性问题。
