Improvements to gaze-contingent visual display systems

描述(由申请人提供)：视线相关的视觉显示系统将眼睛或凝视跟踪系统与视觉刺激的显示连接起来，以根据观看者观看的位置来改变所显示的图像。自近40年前引入以来，它们已被用于解决视觉研究的许多领域。它们还被用于临床评估设备和其他医疗应用，包括康复。理想情况下， 观察者的视线会随着凝视的变化而即时更新。然而，所有这样的系统都在凝视改变和视图更新之间引入了一个滞后：系统延迟。如果系统等待时间足够长，可能会干扰凝视体验对于大多数凝视显示系统来说，最困难的情况是眼跳(非常快)的眼球运动。在目前的最佳实践中，系统组件中的延迟可能会导致凝视和刺激之间的严重不匹配，更严重的是眼睛运动较大。最近，我们开发了一个压缩指数模型来预测眼跳运动，允许根据预测更新显示。眼跳预测与系统延迟的知识相结合，在视线相关的显示中产生较小的误差。当我们开发这个模型时，我们发现眼跳具有弯曲的路径(假设是直线)或非常规的速度轮廓(预期的模式是近似对称的上升然后下降)。这种扫视会导致额外的显示错误，考虑到扫视的弹道性质，这种扫视不是预期的。目的1：研究曲线路径和非常规速度轮廓导致的非标准眼跳的发生条件。这将有助于了解眼跳的产生和控制。目标2：通过将卡尔曼滤波与我们证明的压缩指数模型相结合，开发出一种对先前预测的偏差具有鲁棒性的算法。通过校正弯曲的扫视路径、非常规加速和其他偏离预期轨迹的偏差，这些预测算法将减少或消除更新延迟。更新延迟对视觉任务绩效的影响还不是很清楚，因此在过去的凝视条件下的实验中，这个问题的程度还没有确定。目的3：在三项以不同方式使用视觉性显示的研究中，评估眼跳眼动预测补偿系统潜伏期的效果。这些研究将基于流行的凝视偶发范式，并将揭示滞后如何影响每一个人。这里开发的方法有望成为控制对眼跳运动做出反应的显示器的标准方法，从而在从阅读到机器人再到康复的许多领域产生广泛影响。这个项目是拉塞尔·伍兹和罗刚在哈佛医学院马萨诸塞州眼耳谢彭斯眼科研究所合作完成的。

DESCRIPTION (provided by applicant): Gaze-contingent visual display systems connect an eye- or gaze-tracking system with a display of the visual stimulus, to change the displayed image as a function of where the viewer looks. Since their introduction almost 40 years ago, they have been used to address many areas of vision research. They have also been used in clinical assessment devices and other medical applications, including rehabilitation. Ideally, the observer's view would be instantaneously updated in response to gaze changes. However, all such systems introduce a lag between the gaze change and the view update: the system latency. If the system latency is sufficient, it may interfere with the gaze-contingent experience The most difficult situation for most gaze-contingent display systems occurs with saccadic (very fast) eye movements. With current best practices, delays within the components of the system can lead to substantial mismatches between gaze and stimulus, which are worse with larger eye movements. Recently, we developed a compressed-exponential model to predict saccadic eye movements, allowing the display to be updated based on the prediction. Saccade prediction, when combined with knowledge of system latency, produces smaller errors in gaze-contingent displays. As we developed that model, we found saccades that had a curved path (assumption is straight) or a non-conventional velocity profile (expected pattern is approximately symmetric rise then fall). Such saccades cause additional display errors and are not expected given the ballistic nature of saccades. Aim 1: To investigate conditions under which these non-standard saccades occur due to curved paths and non-conventional velocity profiles. This will inform understanding of saccade generation and control. Aim 2: To develop an algorithm that is robust to departures from prior predictions by combining the Kalman filter with our proven compressed-exponential model. By correcting for curved saccade paths, non-conventional accelerations and other deviations from the expected trajectory, these prediction algorithms will reduce or eliminate update lag. The effect that update lag has on visual task performance is not well known, and therefore the extent of the problem in past gaze-contingent experiments has not been determined. Aim 3: To evaluate the effects of saccadic eye-movement prediction to compensate for system latency in three studies that use gaze- contingent displays in different ways. The studies will be based on popular gaze-contingent paradigms, and will reveal how the lag affects each of them. The methods developed here are expected to become the standard approaches for controlling displays that respond to saccadic eye movements, thereby having wide impact in many fields, from reading to robotics to rehabilitation. This project is a collaboration between Russell Woods and Gang Luo, at the Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School.