Perceptual stability during torsional eye movements

项目摘要/摘要 视觉研究中的一个中心问题是，尽管视网膜连续运动，但我们如何感知一个稳定的世界 眼球运动。了解这些机制对于改善患者的诊断和治疗至关重要。 视力模糊或跳跃，物体定位错误，斜视和斜视，视觉障碍 平衡和跌倒。目前关于眼球运动过程中知觉稳定性的模型忽略了这样一个事实，即眼球旋转- 绕着三个轴旋转。一种重要的机制是使用命令的传出副本来移动眼睛 对眼球运动引起的视网膜运动或移位给予折扣。研究的重点是水平方向 和垂直运动维度，忽略了来自第三(扭转)维度的重要贡献， 其中眼睛绕着视线旋转，例如，每次我们把头朝鞋边倾斜时- 德尔。扭曲的眼睛位置直接影响我们对倾斜(顺时针或逆时针)的感觉，以及 倾斜(在矢状面上的方向)。关于扭转的知识差距的主要原因是 可靠测量扭矩的技术挑战。我们通过开发一种新的方法来克服这一障碍 无创测量扭转眼球运动。这项建议旨在研究知觉效应和大脑 扭转眼球运动的传出复印机制。在指导阶段，候选人将 使用经颅磁刺激(TMS)结合直立知觉测量，并对直立感觉和直立感觉进行比较。 局部眼球运动记录以确定特定皮质回路在考虑静态因素时的作用 在静态头部倾斜过程中发生的扭转。在独立阶段，候选人将研究如何百分比- 在快速扭转眼球运动和扭转前庭眼球反射时，眼球运动会发生改变。 这将使我们能够确定大脑是使用三维还是二维信号来补偿视网膜 由眼球运动引起的运动。这些实验将给我们一个独特的机会，为我们提供关键的新 修改和扩展当前知觉稳定性模型的证据。研究扭转，我们将能够发现- 在计算模型和只解释视网膜两个维度的大脑区域之间定罪 图像与那些解释了所有三个运动维度的图像。归根结底，理解这些机制 将为视力不稳定、空间定向障碍和 瀑布。

PROJECT SUMMARY/ABSTRACT A central question in vision research is how we perceive a stable world despite continuous retinal motion from eye movements. Understanding these mechanisms is critical to improving diagnosis and treatment of patients suffering from blurred or jumping vision, mislocalization of objects, abnormal tilt and slant perception, loss of balance and falls. Current models of perceptual stability during eye movements ignore the fact that the eye ro- tates around three axes. One important mechanism uses the efference copy of the command that moves the eyes to discount the retinal motion or displacement caused by eye movements. Research has focused on the horizontal and vertical dimensions of motion, overlooking the important contribution from the third (torsional) dimension, in which the eyes rotate around the line of sight, as happens, e.g., every time we tilt our head towards the shoul- der. Torsional eye position directly contributes to our perception of tilt (clockwise or counterclockwise) and of slant (orientation in the sagittal plane). The main reason for the gap in knowledge about torsion has been the technological challenge of reliably measuring torsion. We overcame this barrier by developing a new method for measuring torsional eye movements noninvasively. This proposal aims to study the perceptual effects and brain mechanisms of the efference copy for torsional eye movements. During the mentored phase, the candidate will use transcranial magnetic stimulation (TMS) combined with measurements of perception of upright, and tor- sional eye movement recordings to determine the role of particular cortical circuits in taking into account static torsion that occurs during static head tilts. During the independent phase, the candidate will study how percep- tion is altered around the time of quick torsional eye movements and during torsional vestibular ocular reflex. This will enable us to determine if the brain uses signals in three or two dimensions to compensate for the retinal motion induced by eye movements. These experiments will give us a unique opportunity to provide critical new evidence to modify and expand current models of perceptual stability. Studying torsion, we will be able to dis- criminate between computational models and brain areas that only account for the two dimensions of the retinal image versus those that account for all three dimensions of motion. Ultimately, understanding these mechanisms will provide new diagnostic and therapeutic avenues for people with unsteady vision, spatial disorientation, and falls.