Volitional control of neural activity in the oculomotor system

动眼系统神经活动的意志控制

• 批准号: 9901948
• 负责人: Neeraj J Gandhi
• 金额: $ 22.62万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9901948
• 关键词: Action Potentials; Algorithms; Animals; Attention deficit hyperactivity disorder; Auditory; Biomimetics; Brain; Brain Stem; Cells; Cognitive; Data; Development; Dimensions; Disease; Elements; Environment; Exhibits; Eye Movements; Generations; Gold; Individual; Knowledge; Lead; Learning; Mediating; Modeling; Monkeys; Motor; Movement; Neurons; Neurosciences; Parkinson Disease; Patients; Pattern; Population; Process; Rewards; Rodent; Saccades; Schizophrenia; Sensory; Structure; System; Testing; Time; Training; Visual; Volition; Work; base; brain computer interface; design; dynamic system; gaze; improved; innovation; insight; motor control; neural prosthesis; neuroregulation; oculomotor; preservation; relating to nervous system; response; sensory input; statistics; superior colliculus Corpora quadrigemina; visual motor; visual stimulus

PROJECT SUMMARY Sensorimotor transformations are mediated by premotor brain networks where individual neurons represent sensory, cognitive, and movement-related information. In the superior colliculus (SC), a central hub for producing visually-guided saccadic eye movements, many neurons emit a burst of action potentials both in response to a visual stimulus and when generating an eye movement command. These so-called visuomotor neurons project to the brainstem burst generator that produces the saccade. Thus, this downstream element is challenged to differentiate between the incoming “visual” and “motor” bursts. Multiple mechanisms have been proposed to account for movement generation. The “fixed threshold” hypothesis posits that a saccade is produced once the firing rate of either an individual neuron or across a population crosses a threshold, which only happens during the motor burst. Existing data, however, indicate that a simple thresholding mechanism is likely not sufficient and requires consideration of other frameworks. The “optimal subspace” hypothesis uses a dynamical systems approach to propose that a movement is generated when the population activity enters or resides within a particular region of state space. This implies that the state space representations of SC visual and motor bursts are dissociable. The “temporal stability” hypothesis states that a movement is generated when bursting activity across a population of neurons preserves consistent temporal structure for a period of time. Indeed, the stability of SC population activity is reduced during a visual response (“unstable” temporal structure) and increased during an eye movement (“stable” temporal structure). We seek a framework that reconciles these models. Our central hypothesis is that SC population activity is decoded as a movement command when it both exhibits high temporal structure and resides within an optimal subspace. Our specific aim is to employ a closed-loop brain-computer interface in which monkeys are trained to control an auditory cursor by volitionally modulating the activity pattern across multiple SC neurons to lie within a visual or motor subspace and to be temporally stable or unstable. We will first test the optimal subspace and temporal stability frameworks individually before pitting the two against each other in a 2x2 design. Examining the trials in which an eye movement is observed will reveal the patterns used by population activity to represent a movement command. We predict that the animals will be able to modulate population activity along both visual-motor subspace and stable-unstable dimensions, but that the likelihood of movement generation will be the highest when the population activity is both stable and in the optimal subspace.

项目摘要 感觉运动转换是由前运动脑网络介导的，其中单个神经元代表 感觉、认知和运动相关的信息。在上级丘（SC）中， 产生视觉引导的扫视眼球运动，许多神经元发出动作电位的爆发， 在一些实施例中，眼睛运动命令可以是对视觉刺激的响应以及当生成眼睛运动命令时的响应。这些所谓的视觉 神经元投射到产生扫视的脑干爆发发生器。因此，该下游元件是 挑战区分传入的“视觉”和“运动”爆发。多种机制已经被 建议考虑到移动生成。“固定阈值”假说假定扫视是 一旦单个神经元或整个群体的放电率超过阈值， 只会发生在发动机爆发的时候然而，现有的数据表明，一个简单的阈值机制， 可能不够，需要考虑其他框架。“最优子空间”假设使用一个 动态系统的方法提出，当人口活动进入或 存在于状态空间的特定区域中。这意味着SC视觉的状态空间表示 和运动爆发是可以分离的“时间稳定性”假说认为， 当神经元群体的爆发活动在一段时间内保持一致的时间结构时， 时间事实上，SC群体活性的稳定性在视觉响应期间降低（“不稳定”时间响应）。 结构）并且在眼睛运动期间增加（“稳定”时间结构）。我们寻求一个框架， 调和这些模型。我们的中心假设是，SC人口活动被解码为一个运动 命令时，它既表现出高的时间结构，并驻留在一个最佳的子空间。我们的具体 其目的是使用一种闭环脑机接口，在这种接口中，猴子被训练来控制听觉系统。 光标通过意志性地调节多个SC神经元的活动模式，使其位于视觉或运动神经元内， 子空间并且是时间稳定的或不稳定的。我们将首先测试最优子空间和时间稳定性 在2x2的设计中将两者相互对立之前，单独使用框架。审查审判中， 观察到的眼球运动将揭示人口活动用来代表运动的模式 命令我们预测，动物将能够调节人口活动沿着双方的视觉-运动 子空间和稳定-不稳定维度，但运动产生的可能性将是最高的 当种群活动既稳定又处于最优子空间时。