Sensory Feedback for upper limb neuroprosthetics

描述（由申请人提供）：在这项申请中，我们研究如何为上肢假肢的受试者提供真实的感觉反馈。成千上万从战场归来的士兵需要假肢，不仅要能移动，还要能与物体无缝互动。提供反馈的最佳方法是直接进入构成触觉感知的神经回路。最近的研究表明，脑皮层3b区、1区和2区在处理皮肤信息中起着不同的作用，其中3b区神经元负责编码方向，1区负责编码运动，2区负责编码曲率。在这个应用中，我们将研究如何通过直接刺激这些皮质区域的神经元来提供感觉反馈，这些神经元被训练来执行触觉匹配-样本识别任务。有两个具体目标。第一个是研究如何在一个手指垫上提供强度、方向、运动和曲率的感官反馈。在训练非人类灵长类动物（猕猴）完成特征识别任务后，将一个慢性记录阵列植入体感觉皮层。录音的目的是同时记录许多神经元对正在研究的特征的反应。然后，动物将在三种条件下执行任务。1)将机械刺激与机械刺激相匹配（这是动物被训练去执行的条件）2)将机械刺激与机械和电刺激相匹配3)将机械刺激与电刺激相匹配。电刺激将给予特征调谐细胞群

DESCRIPTION (provided by applicant): In this application we investigate how to provide realistic sensory feedback to subjects with upper limb prosthetics. Thousands of soldiers are returning from the war in need of prosthetic limbs that not only can move but also allows them to seamlessly interact with objects. The optimal approach for providing feedback is to tap directly into the neural circuits that underlie tactile perception. Recent studies have shown that areas 3b, 1 and 2 of SI cortex play different roles in processing cutaneous information, with neurons in area 3b responsible for coding orientation, area 1 for motion and area 2 for curvature. In this application we will investigate how to provide sensory feedback by directly stimulation neurons in these cortical areas in animals trained to perform tactile match-to-sample discrimination tasks. There are two specific aims. The first is to investigate how to provide sensory feedback of intensity, orientation, motion and curvature on a single finger pad. After training non-human primates (macaca mulatta) to perform the feature discrimination task, a chronic recording array will be implanted into somatosensory cortex. The goal of the recordings is to simultaneously record from many neurons that are tuned to the feature being studied. The animal will then perform the task under three conditions. 1) Matching a mechanical stimulus with a mechanical stimulus (this is the condition that the animal was trained to perform) 2) Matching a mechanical stimulus with a mechanical and electrical stimulus and 3) Matching a mechanical stimulus with an electrical stimulus. The electrical stimuli will be given to populations of feature tuned cells with the aim of changing the population response of the neurons. This stimulus will be modified in several ways 1) change in current intensity, 2) change in frequency of pulses 3) change in statistical properties of the firing (i.e., biomimetic, uniform, Poisson) and change the degree of correlated firing between cells being modulated. We will develop method to systematically alter the animal's behavior and to determine whether we can produce a population response that mimics the response of the tactile stimulation. The second aim is to train animals to perform a tactile one-back task. This task will determine how to stimulate cortex so that the stimuli can be delivered with minimal spatial and temporal smearing of the electrical signals across fingers. The results from the two aims will provide and understanding of how to provide sensory feedback of complex features to the hand.