Multiple spatial representations during visually-guided behavior

描述（由申请人提供）：愿景是有效控制行动的关键。背侧流投射到后顶叶皮层（PPC），将视觉输入转化为相应的反应来指导不同效应器的运动。一个有影响力的模型提出，背流被组织成专门的视觉运动通道，这些通道是特效特异性的，并且独立运作。本提案的实验旨在严格测试该模型与替代方案，其中通道引导多个效应器的运动并可以相互作用。我们将首先通过记录协调行为中顶叶到达系统（Aim 1）和顶叶扫视系统（Aim 2）的神经元，来测试协调视觉引导行为是否招募效应特异性过程。然后，我们将通过测量顶叶到达和眼跳系统之间的跨区域一致性的强度和功能意义来测试通道是独立运行还是相互作用（目标3）。尽管协调在视觉行为中起着核心作用，但视觉空间的伸手和眼球运动是如何相互影响的，以及PPC内的跨区域相互作用是否构成了这种影响的基础，目前尚不清楚。理解协调视觉行为的机制将有助于我们更普遍地理解视觉行为是如何从不同视觉表征之间的相互作用中产生的。PPC损伤导致视觉共济失调、失用症和忽视，使人衰弱，每年在美国都有许多患者遭受这种痛苦，并付出了巨大的社会代价。了解大脑如何构建视觉空间表征是有效治疗后顶叶损伤患者的基础。

DESCRIPTION (provided by applicant): Vision is critical for effective control of action. The dorsal stream projects to the posterior parietal cortex (PPC), and transforms visual input into corresponding responses to guide movements of different effectors. An influential model proposes that the dorsal stream is organized into dedicated visuomotor channels that are effector-specific and operate independently. Experiments for this proposal seek to rigorously test this model against alternatives in which channels guide movements of multiple effectors and can interact. We will first test whether coordinating visually-guided behaviors recruits effector-specific processes by recording neurons in the parietal reach system (Aim 1) and the parietal saccade system (Aim 2) during coordinated behavior. We will then test whether channels operate independently or interact by measuring the strength and functional significance of cross-areal coherence between the parietal reach and saccade systems (Aim 3). Despite the central role of coordination to visual behavior, how visual space for reaching and eye movements influence each other and whether cross-areal interactions within PPC underlie this influence is not known. Understanding the mechanisms of coordinated visual behavior will help us understand how visual behavior arises from interactions between different visual representations more generally. Damage to the PPC leads to optic ataxia, apraxia and neglect, is debilitating, and is suffered by many patients each year in the US with significant social costs Understanding how the brain constructs visual-spatial representations underlies the effective treatment of patients with posterior parietal damage.