CEREBRAL CORTICAL MECHANISMS FOR CONTROL OF SACCADES

当与关于脑干控制的先进知识水平相比时， 关于眼球扫视运动的研究， 控制眼跳是在其早期阶段。 拟议的主要目标 研究是通过分析大脑皮层对眼跳的控制来研究眼跳的控制。 从平均值得到的前视电位的时空分布 脑电图（EEG）记录。 这种技术将 被用来测试一个模型的皮质控制切除术， 眼跳源于当前的知识状态。 根据 模型，弓形额眼场（FEF）控制自愿视觉- 相关的扫视，顶叶促进的性能， 视觉诱发反射性眼跳的上级丘 视觉注意力的释放和转移，以及内侧额叶 与基底神经节一起控制自我发起的扫视， 视觉目标的缺乏和对不需要的扫视的抑制。 该模型将通过测量以下条件下的前accadic电位进行测试 不同刺激和不同程度的随意控制条件 在正常受试者和患有影响扫视的疾病的患者中， 包括帕金森病和亨廷顿病。 除了 获得关于扫视的正常控制的信息，结果 应该为研究具有受损扫视的障碍提供基础。 控制，并进一步了解电机控制机制一般。 该研究计划的第二个目标是开发一种替代品 眼前肌电神经生理检查 潜力 棘波电位（SP），眼外的表现 肌肉或眼运动神经活动，将在正常受试者中进行测试 和患有眼球运动障碍的患者，以开发其诊断和 预测能力。

When compared to the advanced level of knowledge about brainstem control of saccadic eye movements, the understanding of how the cerebral cortex controls saccades is in its early stages. The major goal of the proposed research is to study the cortical control of saccades by analyzing the spatio-temporal distribution of presaccadic potentials from averaged electroencephalographic (EEG) recordings in humans. This technique will be employed to test a model for a trichotomy of cortical control of saccades derived from the current state of knowledge. According to the model, the arcuate frontal eye field (FEF) controls voluntary visually- related saccades, the parietal lobe facilitates the performance by the superior colliculus of visually-elicited reflexive saccades by allowing the release and shifting of visual attention, and the medial frontal lobe in conjunction with the basal ganglia govern self-initiated saccades in the absence of visual targets and the suppression of unwanted saccades. The model will be tested by measuring presaccadic potentials under conditions with varying stimuli and varying degrees of voluntary control in normal subjects and patients with diseases affecting saccadic initiation, including Parkinson's and Huntington's diseases. Aside from gaining information about the normal control of saccades, the results should provide a foundation for studying disorders with impaired saccadic control, and further knowledge about motor control mechanisms in general. A secondary goal of the research program is to develop an alternative neurophysiologic test to ocular electromyography with presaccadic potentials. The spike potential (SP), a manifestation of extraocular muscle or ocular motor nerve activity, will be tested in normal subjects and patients with ocular motility disorders to develop its diagnostic and prognostic capabilities.