STUDIES OF LOW VISION READING AND FACE RECOGNITION

中心视野丧失的低视力受试者阅读速度要慢得多 在标准临床测量的基础上预期的 视功能(如视力和对比敏感度)。 所提议的研究计划的主要目标是确定 是什么限制了这组受试者的阅读表现？ 探索新的图像增强技术以规避 在缺乏中央视觉的情况下阅读的视觉限制。 我们将研究正常青少年和老年人的阅读表现。 观察者和低视力受试者中，由于 黄斑疾病，主要是老年性黄斑病变。要确定 正常周边视力对阅读的限制 观察者将在人工盲点存在的情况下阅读文本 用双浦肯野眼球追踪器稳定在视网膜上。自.以来 不适当的眼球运动可能严重限制外周阅读， 我们还将通过呈现课文一来研究阅读表现 在固定的视网膜位置一次一个字。这项技术，众所周知 作为快速的连续视觉演示，或RSVP，几乎消除了 眼球跳动的必要性。我们将确定其程度 对此低视力受试者的外周视网膜表现为 正常外周视网膜。我们将测量空间相位或 使用鉴相和游标任务的位置敏感度。 侧向制造(“拥挤”)效应将由 在有或没有侧翼的情况下测量字母识别 模式和元对比掩码(向后和向前掩码 在时间域中)将通过单词识别来测量 范例。空间欠采样将通过比较 光栅片的检测和方向识别，以及 时间欠抽样将通过比较CFF和两个- 脉搏辨别。在每种情况下，我们都会比较性能 有中央暗点的低视力受试者与正常视力受试者的对比 受试者使用眼球跟踪器控制外围观看。我们会 确定低视力阅读能力与大小的关系， 中央暗点的位置和密度，以及发现的 周围视功能异常。给了一个更好的 对周边阅读视觉限制的理解 性能，我们将研究新的技术来增强或 修改图像以提高性能。我们会 探索非线性放大和增加字母间距，以 克服拥挤问题，低通空间和时间滤波 减少侧向和元对比度的遮蔽，并使用静电 和动态纹理，以改善字母分离。

Low-vision subjects with central field loss read much more slowly than would be expected on the basis of standard clinical measures of visual function (e.g. visual acuity and contrast sensitivity). The principal goal of the proposed research program is to determine what limits reading performance in this group of subjects and to explore new techniques of Image enhancement to circumvent the visual limitations on reading in the absence of central vision. We will study reading performance in young and elderly normal observers and in low-vision subjects with central scotomas due to macular disease, primarily age-related maculopathy. To determine the limitations on reading of normal peripheral vision, normal observers will read text in the presence of an artificial scotoma stabilized on the retina with a dual-Purkinje eye tracker. Since inappropriate eye movement may severely limit peripheral reading, we will also study reading performance by presenting the text one word at a time in a fixed retinal location. This technique, known as rapid serial visual presentation, or RSVP, virtually eliminates the need for saccadic eye movements. We will determine the extent to which the peripheral retina of low vision subjects behaves like normal peripheral retina. We will measure spatial phase or position sensitivity using phase discrimination and vernier tasks. Lateral making ("crowding") effects will be investigated by measuring letter recognition in the presence or absence of flanking patterns, and metacontrast masking (backwards and forwards masking in the temporal domain) will be measured with a word recognition paradigm. Spatial undersampling will be investigated by comparing detection and orientation discrimination of grating patches, and temporal undersampling will be evaluated by comparing CFF with two- pulse discrimination. In each case we will the compare performance of low-vision subjects with central scotomas to that of normal subjects using eye-tracker controlled peripheral viewing. We will determine the relation of low-vision reading ability to the size, location, and density of central scotomas, and any discovered abnormalities of peripheral visual function. Given a better understanding of the visual limitations on peripheral reading performance, we will investigate new techniques for enhancing or modifying the image in order to improve performance. We will explore non-linear magnification and increased letter spacing to overcome crowding problems, low-pass spatial and temporal filtering to reduce lateral and metacontrast masking, and the use of static and dynamic texture to improve letter segregation.