NEURAL CONTROL OF VISUALLY GUIDED EYE MOVEMENTS

视觉引导的跳眼运动的皮层控制涉及前、后两大系统。前部系统由额叶视野（FEF）和背内侧额叶皮层（DMFC）组成，可直接连接脑干动眼神经中枢。后脑系统由枕皮质和顶叶皮质的几个区域组成，似乎与脑干没有直接联系；大多数情况下，它通过上丘或额叶到达这些中心。这项工作的主要重点是了解这两个皮层系统控制视觉引导眼球运动的方式，它们彼此之间的区别以及它们如何相互联系。研究人员将使用记录、电微刺激、可逆失活和损伤等方法来研究行为正常的恒河猴。部分工作将利用慢性多个单细胞记录，这将使我们能够在较长时间内研究神经元的特性，以研究单个神经元的组织变化。为了研究动物的视觉和视觉运动能力，我们设计了一系列广泛的测试，其中一些是新的。这些测试之一，利用具有各种时间异步的双目标。将被用于研究猴子和大脑前后眼动系统损伤患者的消失现象。这项拟议的研究将增加我们对眼睛和肢体运动的神经控制的了解，并使我们能够比较猴子和人类的这些系统。

The cortical control of visually guided saccadic eye movements involves of two major systems, the anterior and the posterior. The anterior system, comprised of the frontal eye fields (FEF) and the dorsomedial frontal cortex (DMFC), has direct access to brainstem oculomotor centers. The posterior system, comprised of several regions of the occipital and parietal cortices, does not appear to have direct access to the brainstem; for the most part it reaches these centers either through the superior colliculus or through the frontal lobe. The major focus of the proposed work is to understand the manner in which these two cortical systems control visually guided eye movements, how they differ from each other and how they interconnect. Behaving rhesus monkeys will be studied using recording, electrical microstimulation, reversible inactivation, and lesion methods. Part of the work will utilize chronic multiple single-cell recordings that will enable us to study neuronal properties over extended time periods to study organizational changes in individual neurons. We have devised an extensive battery of tests, some of them new, to study the visual and visuo-motor capacities of animals. One of these tests that utilizes dual targets presented with various temporal asynchronies. will be used to study the extinction phenomenon both in monkeys and patients with brain damage to the anterior and posterior eye-movement systems. The proposed research will increase our knowledge of the neural control of eye and limb movements and will allow us to compare these systems in monkeys and humans.