Modulation in the use of multisensory information during voluntary action

当你举起一个水瓶放在玻璃杯上时，你肌肉和眼睛中的感受器会暴露在不同的兴奋模式中。首先举起瓶子需要调整四肢肌肉产生的初始力，这就是众所周知的冲动调节。之后，将喷嘴带到玻璃上需要进行额外的调整，即所谓的肢体靶标调节。虽然通过对视觉运动功能的研究已经发现了这些感觉运动过程，但对肌肉受体(即本体感觉)在这些过程中的作用知之甚少。因此，目前的研究计划将揭示视觉和本体感觉对冲动和肢体靶标调节过程的贡献。第一个系列的感觉运动研究将在不同的运动幅度和持续时间下，在伸展运动的不同部分呈现短暂的视觉闪烁。在关于视觉在自愿运动中何时被利用的理论辩论的基础上，将开发出在不同持续时间和幅度的运动中发生的不同感觉运动过程的简约框架。第二个系列的感觉运动研究将在短暂的视觉闪烁期间增加视觉干扰。这将包括移动形成视觉背景的随机点云和/或目标位置的移动。由于脉冲调节被认为发生在肢体-靶标调节之前，因此预计当运动早期出现背景扰动时，将对肢体轨迹产生显著影响。反过来，当目标跳跃在运动过程中稍后呈现时，预计将对肢体轨迹产生显著影响。第三系列感觉运动研究将结合肌腱振动操作，这种操作在试验之间呈现，并降低肌肉感受器的敏感性(即本体感觉)。通过以上两个系列的精选研究，肌腱振动研究将测试本体感觉对冲动和肢体靶标调节过程的贡献。此外，当结合视觉干扰(即背景和/或目标)时，这些研究将有助于确定视觉和本体感觉是否整合在一起来调节冲动和肢体目标。最后一个系列将使用知觉报告(例如，“你的肢体最终位置是否低于或超过目标？”)。视觉和/或本体感觉干扰对感知肢体终点的影响有望证实感觉运动研究的结果。总体而言，确定哪些感觉信息来源对冲动和肢体靶标调节起主要作用，将完善感觉运动控制的模型。此外，这些模型将为各种实用设计(例如，人机界面、康复计划和机器人、运动训练协议)提供参考。

As you lift a water bottle and bring it over a glass, the receptors in your muscles and eyes are exposed to different excitation patterns. Lifting the bottle first requires adjusting the initial forces generated by your limb muscles, which is known as impulse regulation. After, bringing the spout over the glass requires additional adjustments, known as limb-target regulation. Although these sensorimotor processes have been discovered through studies of visual-motor functions, little is known about the contribution of muscle receptors (i.e., proprioception) to these processes. Thus, the current research program will unravel the contribution of vision and proprioception to the impulse and limb-target regulation processes. The first series of sensorimotor studies will present brief flashes of vision at different portions of a reaching movement, while employing different movement amplitudes and durations. Building upon theoretical debates about when vision is utilized during a voluntary movement, parsimonious frameworks of the different sensorimotor processes taking place during movements of different durations and amplitudes will be developed. The second series of sensorimotor studies will add visual perturbations during the brief flashes of vision. That will include moving a cloud of random dots forming a visual background and/ or a shift in target location. Because impulse regulation is thought to occur before limb-target regulation, it is expected that background perturbations will have significant effects on limb trajectories when presented early during the movement. In turn, target jumps are expected to have significant effects on limb trajectories when presented later during the movement. The third series of sensorimotor studies will incorporate a tendon vibration manipulation that is presented between trials and reduces the sensitivity of muscle receptors (i.e., proprioception). Using selected studies from the two series above, tendon vibration studies will test for the contribution of proprioception for impulse and limb-target regulation processes. As well, when combined with visual perturbations (i.e., background and/ or target), these studies will help determine if vision and proprioception are integrated for impulse and limb-target regulation. The last series will employ perceptual reports (e.g., "Did your limb final position undershot or overshot the target?"). The influence of vision and/or proprioceptive perturbations on the perceived limb endpoint are expected to corroborate the results from the sensorimotor studies. Overall, determining which sources of sensory information predominantly contribute to impulse vs. limb-target regulation will refine models of sensorimotor control. As well, these models will inform various practical designs (e.g., human-machine interfaces, rehabilitation programs and robots, sport training protocols).