The Role of Extrastriate and Parietal Cortex in the Control of Steering

描述（由申请人提供）：该项目的主要目的是了解允许灵长类动物（包括人类）使用视觉运动信息进行导航的感知和生理机制。先前的工作已经阐明了模拟自我运动的被动感知机制，但这与实际使用运动信息来引导正在进行的轨迹相去甚远。在视觉导航中有两个主要的线索：目标（和障碍物）的位置和“光流”信息，提供关于一个人在世界上的即时轨迹的即时反馈。这个实验将测试在视觉皮层更高层次的运动敏感神经元如何处理，联合收割机，并代表这两个线索的指导正在进行的行为。生理实验将针对背侧纹外皮层“运动系统”最高层的两个区域：内侧上级颞区（MST）和腹侧顶内区（VIP）。我们将测试这些区域的信号如何与最近开发的主动转向任务的性能相关。在这项任务中，非人类灵长类动物控制虚拟现实环境中呈现的虚拟轨迹。这允许对线索进行精确控制，也允许形成该提案核心的生理实验。在目标1和2的生理学实验中测试的具体假设涉及这些信号支持复杂自然任务的机制。在目标3中，我们将开发一个生物现实的，实验约束的神经系统如何控制转向行为的计算模型。这些目标的成功实现将使我们能够了解大脑中支持这种指导的位置，以及那里的信号如何与行为能力相关。从纯科学的角度来看，这些信息很重要，也可能为视觉修复术的创建提供信息，以帮助视力受损患者导航，并可能有助于开发改进的机器人导航系统。

DESCRIPTION (provided by applicant): The principal aims of this project are to understand the perceptual and physiological mechanisms that allow primates, including man, to navigate using visual motion information. Previous work has elucidated the mechanisms of the passive perception of simulated self-motion, but this is a far cry from actually using motion information t guide an ongoing trajectory. There are two primary cues used in visual navigation: the position of targets (and obstacles) and the "optic flow" information that provides instantaneous feedback about one's immediate trajectory in the world. The experiments in this proposal wil test how motion-sensitive neurons in the higher levels of visual cortex process, combine, and represent these two cues for the guidance of ongoing behavior. The physiological experiments will be directed at two areas at the highest levels of the "motion system" in dorsal extrastriate cortex: the medial superior temporal area (MST) and the ventral intraparietal area (VIP). We will test how the signals in these areas correlate with performance on a recently developed active steering task. In this task, nonhuman primates control a virtual trajectory presented in a virtual reality setting. This allows precise control of the cues and also enables the physiological experiments that form the core of the proposal. The specific hypotheses under test in the physiological experiments in Aims 1 and 2 concern the mechanisms by which these signals support performance of a complex, natural task. In Aim 3, we will be developing a biologically realistic, experimentally-constrained computational model of how the nervous system controls steering behavior. Successful conclusion of these aims will allow us to understand both where in the brain such guidance is supported, and how the signals there relate to behavioral capabilities. This information is important from a pure scientific perspective, and will also potentially inform the creation of visual prosthetics to assist navigation by visually impaired patients, and could help the development of improved robotic navigation systems.