FRONTAL EYE FIELDS IN SACCADIC AND SMOOTH EYE MOVEMENTS

最近的研究证实，灵长类动物的额叶眼场（FEF）具有 在产生随意扫视眼球运动中的重要作用， 与先前的报告相反，FEF中的单位活动非常适合 对于这样的角色。 拟议的实验将进一步研究 FEF在产生自愿眼球运动中的作用。 A FEF区域 这似乎与平稳追踪眼球运动有关， 使用单神经元记录、微刺激、解剖追踪， 眼部检查后病变。 因为FEF神经活动表明 在随意眼球运动的预测方面的作用， 还将测试在利用目标的预测方面的缺陷 动作 由于临床病例表明眼睛失去自主控制， 运动与额叶病理，使自愿的能力， 将测试不直接由视觉目标引导的扫视。 一些FEF 单位响应听觉刺激;拟议的研究探讨了 假设这些反应的功能直接扫视眼球运动 声音来源。 实验包括映射听觉感受性 场，测试注视方向对听觉反应的影响， 并测试作为行为功能的反应增强 刺激的重要性。 生理学研究表明， 是一个离散的皮层区域，具有系统的眼跳表示， 度量和细分与顺利的追求。 放射性 将使用2-脱氧-D-葡萄糖方法测量代谢活性， 检查FEF的整体功能组织。 代谢 FEF和其他结构在不同的眼科行为将是 分析;建议的情况下，旨在对比的轨迹扫视 平滑追踪区域，并绘制两者的度量的地形图。 眼睛运动的类型。 这些研究的结果应该阐明 额叶皮质参与介导复杂的眼部行为 正常个体，可能对大型异质性 眼动障碍的神经系统患者人群。

Recent studies confirm that the primate Frontal Eye Fields (FEF) have animportant role in the generation of voluntary saccadic eye movements and that unit activity in the FEF is, contrary to earlier reports, well-suited for such a role. The proposed experiments will further investigate the role of the FEF in the generation of voluntary eye movements. A FEF region that appears to be related to smooth pursuit eye movements will be studied using single neuron recordings, microstimulation, anatomical tracing, and oculomotor testing following lesions. Because FEF neural activity suggests a role in predictive aspects of voluntary eye movements, this lesion study will also test for deficits in utilizing predictive aspects of target movements. Since clinical cases suggest a loss of voluntary control of eye movements with frontal lobe pathology, the ability to make voluntary saccades not directly guided by visual targets will be tested. Some FEF units respond to auditory stimuli; the proposed research explores the hypothesis that these responses function to direct saccadic eye movements towards sound sources. Experiments include mapping auditory receptive fields, testing the effects of direction of gaze upon auditory responses, and testing for an enhancement of responses as a function of behavioral significance of the stimuli. Physioilogical studies have indicated the FEF to be a discrete cortical zone with a systematic representation of saccade metrics and a subdivision concerned with smooth pursuit. The radioactive 2-deoxy-D-glucose method of measuring metabolic activity will be used to examine the overall functional organization of the FEF. Metabolism in the FEF and other structures during different oculomotor behaviors will be analyzed; the proposed cases are designed to contrast the loci of saccadic and smooth pursuit regions and map the topography of the metrics of both types of eye movements. The results of these studies should illuminate the involvement of frontal cortex in mediating complex oculomotor behavior in normal individuals and may have clinical value for the large heterogeneous population of neurological patients with eye movement disorders.