NEURAL CONTROL OF VISUALLY GUIDED EYE MOVEMENTS

视觉引导的眼球跳动的皮质控制涉及两个主要系统，前部和后部。前部系统由额叶眼区(FEF)和背内侧额叶皮质(DMFC)组成，可直接进入脑干动眼神经中心。后部系统由枕叶和顶叶皮质的几个区域组成，似乎不能直接到达脑干；大多数情况下，它要么通过上丘，要么通过额叶到达这些中心。这项拟议工作的主要重点是了解这两个大脑皮层系统控制视觉引导眼球运动的方式，它们之间有何不同，以及它们是如何相互联系的。将使用记录、电微刺激、可逆灭活和毁损方法来研究恒河猴的行为。部分工作将利用慢性多个单细胞记录，使我们能够研究延长时间段的神经元属性，以研究单个神经元的组织变化。我们设计了一系列广泛的测试，其中一些是新的，以研究动物的视觉和视觉运动能力。这些测试中的一项利用了呈现各种时间异步性的双重目标。将被用来研究猴子和大脑前后部眼球运动系统受损的患者的灭绝现象。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知识，并使我们能够在猴子和人类身上比较这些系统。

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.