EGOCENTRIC LOCALIZATION AND SACCADIC PLASTICITY

意义 快速手指向的实验证明了视网膜外眼 位置信号（ERS）比视觉内比较更精确 视觉稳定性的实验和研究曾经似乎允许。 目光 指向研究得出了类似的结论，但这些实验是 存在严重缺陷，早就应该进行复制。 电机系统 相关性和详细的时间过程的ERS还没有研究在一个 自我中心的本地化模式。 的适应性 扫视眼球运动提出了一个问题，即眼球位置是否可以 与ERS脱钩;答案将对 适应性变化的轨迹和ERS的来源。 最后， 有人建议，缓慢或延迟的运动可能会被编程， 一个不同的基础，因此反映了错误没有看到与快速 动作 目标和方法 我们的目标是解决这些问题， 析因研究 对于几个本地化措施和状态中的每一个， 扫视增益适应，我们将准确地确定时间过程， 在黑暗中出现的昏暗和明亮的闪光的局部化，之前， 在水平扫视期间和之后。 正常的人类受试者将执行 四种不同的定位任务：即时或延迟指向 用眼睛或看不见的手。 扫视将：正常，增益适应 在训练的早期，在训练的后期适应增益。 扫视将是 适应操作的视觉反馈，眼睛位置由 弥散性角膜缘反射 拟议的研究应有助于澄清 感知运动系统，特别是当它决定基于视觉的 电机性能

Significance Experiments with rapid hand pointing demonstrate an extraretinal eye position signal (ERS) that is more accurate than intravisual comparison experiments and studies of visual stability once seemed to allow. Gaze pointing studies have drawn similar conclusions, but these experiments are seriously flawed and replication is long overdue. The motor system dependence and detailed time course of the ERS have not been studied in a well-controlled egocentric localization paradigm. The adaptability of saccadic eye movements raises the question of whether eye position can be decoupled from the ERS; the answer would have important implications for the locus of adaptive change and the source of the ERS. Finally, it has been suggested that slow or delayed motor movements might be programmed on a different basis, and therefore reflect errors not seen with rapid movements. Objectives and Methods Our objective is to address these questions with a within-subjects, factorial study. For each of several localization measures and states of saccadic gain adaptation, we will accurately determine the time course of localizations of dim and bright flashes presented in the dark, before, during, and after horizontal saccades. Normal human subjects will perform four different localization tasks: immediate or delayed pointing either with the eye or with unseen hand. Saccades will be: normal, gain-adapted early in training, and gain-adapted late in training. Saccades will be adapted with manipulated visual feedback, and eye position monitored by diffuse limbus-reflection. The proposed studies should help clarify the functional connectivity of the perceptual-motor system, particularly as it determines visually-based motor performance.