Hand proprioception and sensorimotor interplay

描述（由申请人提供）：手是人类最复杂、最通用、最关键的感觉器官之一。来自手部的感觉信号在指导对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，以确保正确地抓住物体，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，需要高度集中注意力。与受到大量实验关注的触觉相比，大脑对手的位置和动作的表征却知之甚少。的确，本体感觉的研究在测量和控制感官输入方面面临着独特的技术挑战，而视觉和听觉的监测器和扬声器已经商品化。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官形态。我们的目标是应用严格和定量的方法来研究灵长类动物本体感觉的皮层基础，重点是手部运动学和姿势。此外，我们试图了解本体感觉表征如何与皮层中的运动表征相互作用以指导行为。为了达到这些目的，猴子将执行两项任务：一项是抓取任务，物体的形状和大小都大不相同；另一项是手指按压任务，在这项任务中，动物被指示做出个性化的手指运动。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层本体感觉区和运动区引起的神经元活动。然后，我们将使用各种数学技术来(1)了解手部运动和位置是如何在单个神经元和神经元群的活动中表征的；(2)表征本体感觉和运动表征之间的相互作用，以了解这种感觉-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电刺激皮质来传递感觉反馈的方法，用于上肢神经假肢。关于假肢的位置和运动的本体感觉信息对于一个完整的假肢是必不可少的，因为它在天然肢体中很重要。因此，拟议项目的结果将告知如何将本体感觉反馈纳入感测神经假体。

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.