Hand proprioception and sensorimotor interplay

描述（由申请人提供）：手是人类最复杂、最多功能和最重要的感觉器官之一。来自手部的感觉信号在指导物体的灵巧操作中起着关键作用。如果没有这些信号，我们就需要不断地观察我们的手，以确保物体被正确地抓住，监控我们对工具的使用，并保持其正确的形状。此外，简单的日常生活活动，如系鞋带，或转动门把手，将是缓慢和笨拙的，并需要极大的专注力。与触觉相比，触觉已经受到了很多实验的关注，手的位置和手的运动在大脑中的表征知之甚少。事实上，与视觉和听觉不同，监视器和扬声器是商业上可用的，本体感受研究在测量和操纵感官输入方面提出了独特的技术挑战。然而，随着越来越复杂的技术变得可用，我们能够更富有成效地研究这种重要的感觉方式。 我们的目标是应用严格和定量的方法来调查灵长类动物的本体感觉的皮质基础，重点是手的运动学和姿势。此外，我们试图了解本体感受表征如何与皮质中的运动表征相互作用以指导行为。为了达到这些目的，猴子会执行两项任务：一项是抓取任务，对象的形状和大小相差很大;另一项是手指按压任务，动物被指示进行个性化的手指运动。当猴子执行这些任务时，我们将使用基于相机的运动跟踪系统测量它们的手部运动，并使用长期植入的高密度多电极阵列记录在皮质的本体感受和运动区域中诱发的神经元活动。然后，我们将使用各种数学技术来（1）理解手的运动和位置是如何在单个神经元和神经元群体的活动中表现出来的，（2）描述本体感受和运动表征之间的相互作用，以理解这种感觉运动相互作用在运动控制中的作用。 我们的实验室目前正在开发通过大脑皮层的电刺激来传递感觉反馈的方法，用于上肢神经假体。关于假肢的位置和运动的本体感受信息对于完整的假肢是必不可少的，原因与其在原生肢体中的重要性相同。因此，拟议项目的结果将告知如何将本体感受反馈纳入传感器神经假体。

DESCRIPTION (provided by applicant): The hand is one of the most complex, versatile, and critical human sensory organs. Sensory signals from the hand play a key role in guiding the dexterous manipulation of objects. Without these signals, we would need to constantly watch our hand to ensure that an object was properly grasped, to monitor our use of a tool, and to maintain its proper shape. Furthermore, simple activities of daily living, such as tying one's shoe, or turning a door knob, would be slow and clumsy, and require great concentration. In contrast to the sense of touch, which has received a lot of experimental attention, the representation of hand position and hand movements in the brain is poorly understood. Indeed, unlike vision and audition, for which monitors and speakers are commercially available, proprioception research presents unique technological challenges in measuring and manipulating the sensory input. As increasingly sophisticated technologies become available, however, we are able to more fruitfully investigate this important sensory modality. Our objective is to apply rigorous and quantitative methods to investigate the cortical basis of proprioception in primates, with an emphasis on hand kinematics and posture. Furthermore, we seek to understand how proprioceptive representations interact with motor representations in the cortex to guide behavior. To these ends, monkeys will perform two tasks: a grasping task, with objects different widely in shape and size, and a finger-press task, in which the animal is instructed to make individuated finger movements. While the monkeys perform these tasks, we will measure their hand movements using a camera- based motion tracking system, and record, using chronically implanted high-density multi-electrode arrays, the neuronal activity evoked in proprioceptive and motor areas of the cortex. We will then use a variety of mathematical techniques to (1) understand how hand movements and position are represented in the activity of individual neurons and of neuronal populations and (2) characterize the interactions between proprioceptive and motor representations to understand the role of this sensorimotor interplay in motor control. Our labs are currently developing approaches to convey sensory feedback through electrical stimulation of cortex for use in upper-limb neuroprostheses. Proprioceptive information about the position and movements of the prosthetic limb is essential for a complete prosthetic limb for the same reasons it is important in the native limb. Results from the proposed project will thus inform how to incorporate proprioceptive feedback in sensorized neuroprostheses.