Cortical & Subcortical Control of Saccades and Attention

描述（由申请人提供）：为了生存，动物必须面向重要的刺激，而忽略不相关的。我们的长期目标是了解大脑如何选择视觉定向的目标，包括扫视眼球运动和没有眼球运动的注意力转移。眼跳的目标选择位于感觉系统和运动系统之间。本项目探讨两个结构的功能，传统上被认为是运动区：上级丘（SC），一个皮层下区域的重要扫视，和额叶眼场（FEF），解剖学上连接的皮层区域。在这两个领域都观察到了与目标选择相关的活动。然而，这仍然是有争议的，特别是对SC来说，这些区域是否参与选择看哪里，或者只是接受选择相关的活动，为产生运动做准备。我们将测试的假设，这些领域发挥功能的作用，在目标选择暂时失活的小区域的SC或FEF和测试性能的任务，区分纯粹的感觉或运动缺陷的缺陷，在目标选择。比较将揭示这两种结构在它们对目标选择的贡献方面是如何彼此不同的（目标1）。我们还将研究SC和FEF的相互作用。通常认为SC是在皮质区域如FEF的控制下，即使解剖学通路也从SC回到FEF。我们将测试的假设，SC活动影响目标选择的FEF，使用单单位记录和失活。这将揭示这两个区域是否主要以前馈方式相互作用，或者来自SC的反馈是否影响皮质目标选择（目标2）。有证据表明，一些相同的大脑区域控制眼球运动和注意力转移。我们将通过调查暂时中断SC或FEF活动对需要转移焦点注意力的任务的影响来验证这一假设（目标3）。这些实验将有助于揭示视觉定向系统的结构，从而更好地理解扰乱眼球运动和注意力的人类神经综合征。

DESCRIPTION (provided by applicant): To survive, animals must orient toward important stimuli while ignoring irrelevant ones. Our long-term goal is to understand how the brain selects targets for visual orienting, including saccadic eye movements and shifts of attention without eye movements. Saccade target selection lies at the interface between sensory and motor systems. This project probes the functions of two structures traditionally regarded as motor areas: the superior colliculus (SC), a subcortical region important for saccades, and the frontal eye field (FEF), an anatomically connected cortical region. Activity correlated with target selection has been observed in both areas. However, it is still debatable, particularly for the SC, whether these areas are involved in selecting where to look, or simply receive selection-related activity in preparation for generating a movement. We will test the hypothesis that these areas play functional roles in target selection by temporarily inactivating small regions of either the SC or FEF and testing performance in tasks that distinguish purely sensory or motor deficits from deficits in target selection. Comparisons will reveal how the two structures differ from each other in their contributions to target selection (Aim 1). We will also study the interactions of the SC and the FEF. It is usually assumed that the SC is under the control of cortical regions such as FEF, even though anatomical pathways also lead from the SC back to the FEF. We will test the hypothesis that SC activity influences target selection in the FEF, using single-unit recording and inactivation. This will reveal whether the two areas interact primarily in a feed-forward manner, or whether feedback from the SC influences cortical target selection (Aim 2). Evidence suggests that some of the same brain areas control both eye movements and attention shifts. We will test this hypothesis by investigating the consequences of temporarily disrupting activity in the SC or FEF on tasks requiring shifts of focal attention (Aim 3). These experiments will help to reveal the architecture of the visual orienting system, leading to a better understanding of human neurological syndromes that disrupt eye movements and attention.