VISUAL MOTOR TRANSFORMATION IN CORTEX

描述（由申请人提供）：追求视觉目标在日常生活中无处不在。这项任务似乎毫不费力，但需要大量的处理才能完成。我们的目标是更好地理解动作背后的视觉空间信息处理。为此，我们使用非人类灵长类动物的视觉引导触摸作为模型系统。我们的第一个目的是确定后顶叶区对视觉引导到达的运动学和动力学的具体贡献。我们将使用一种新的方法来精确定位整个顶棚内沟可逆注射的位置。每次注射后，我们将测试动物的任务面板（到达，扫视和视觉搜索），然后对失活部位进行成像。这种方法是全面的，比单一单元记录更能显示顶叶区域的真实功能贡献。我们的第二个目标是确定和量化与双手协调相关的后顶叶皮层的活动成分。灵长类动物通常用两只手臂一起完成单臂很难或不可能完成的任务。临床证据表明，顶叶皮层在双手协调中起作用。我们的结果将有助于区分两种特定的模型，如何在单个神经元水平上表现出双手协调。我们的第三个目标是量化后顶叶神经元在评估目标和决策过程中的活动，并将其与在跳眼运动决策过程中观察到的活动进行比较。最近的研究表明，跳眼运动有一个特定的决策模型。我们的研究结果将表明，对于不同类型的动作，目标评估和决策回路的顶叶回路是相同的还是不同的（到达与扫视）。实现这些目标将有助于我们理解感觉到运动转化、运动协调和决策的早期过程。研究结果将为帮助中风和其他中枢损伤恢复的合理策略的设计提供重要信息，并为新一代假肢设备设计最佳的脑接口。本建议的中心目标是了解视觉引导到达的视觉空间信息的早期处理。实现这一目标将有助于临床医生了解并最终扭转由顶骨和枕部中风以及其他脑外伤引起的损害。了解大脑是如何产生和表达运动计划的，对于为截肢、脊髓损伤和肌萎缩侧索硬化症等疾病患者开发有前途的神经假肢也至关重要。

Description (provided by applicant): Reaching towards a visual target is ubiquitous in daily life. The task seems effortless, yet requires substantial processing to accomplish. Our goal is to better understand the visuospatial information processing underlying action. For this purpose, we use visually-guided reaching in the non-human primate as a model system. Our first aim is to determine the specific contributions of posterior parietal areas to the kinematics and dynamics of visually-guided reaching. We will use a novel method to precisely localize the sites of reversible injections placed throughout the intraparietal sulcus. After each injection we will test animals on a panel of tasks (reaches, saccades and visual search) and then image the site of inactivation. This method is comprehensive and better indicates the true functional contributions of parietal areas than can be achieved through single unit recording. Our second aim is to identify and quantify components of activity in posterior parietal cortex that are related to bimanual coordination. Primates commonly use the two arms together to accomplish tasks that are difficult or impossible to perform with a one arm. Clinical evidence suggests a role of the parietal cortex in bimanual coordination. Our results will help distinguish between two specific models of how bimanual coordination might be manifest at the level of individual neurons. Our third aim is to quantify the activity of posterior parietal neurons during evaluation of targets and decision-making in performing reaches, and to compare that activity to that observed during decision-making for saccadic eye movements. Recent work has suggested a specific model for decision-making for saccadic eye movements. Our results will indicate whether parietal circuits for target evaluation and decision circuits are the same or different for different kinds of action (reaches versus saccades). Achieving these aims will help us understand the early processes involved in sensory to motor transformation, motor coordination, and decision-making. The results will critically inform the devise of rational strategies for aiding recovery from strokes and other central damage, as well as the design of optimal brain interfaces for a new generation of prosthetic devices. PUBLIC HEALTH RELEVANCE The central goal of this proposal is to understand the early processing of visuospatial information for visually- guided reaching. Achieving this goal will help clinicians to understand and ultimately reverse the damage caused by parietal and occipital strokes and other brain trauma. Understanding how the brain generates and represents plans for movement is also critical to the development of promising neuroprosthetics for patients with amputations, spinal cord injuries, and disorders such as amyotrophic lateral sclerosis.