STUDIES OF LOW VISION READING AND FACE RECOGNITION

低视力阅读和人脸识别的研究

• 批准号: 3262388
• 负责人: GARY S RUBIN
• 金额: $ 17.68万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-01-01 至 1993-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3262388
• 关键词: aging; eye movements; face; image enhancement; perceptual maskings; reading; retina disorder; saccades; scotoma; sequential perception; vision disorders; vision tests; visual perception; visual photosensitivity; visual tracking

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.

中央场损失的低视频受试者读取更慢得多 比根据标准临床措施预期的 视觉功能（例如，视敏度和对比度灵敏度）。 拟议的研究计划的主要目标是确定 什么限制了这组主题中的阅读表现以及 探索图像增强的新技术以规避 在没有中央视觉的情况下阅读的视觉限制。 我们将研究年轻和老年人的阅读表现 观察员和在具有中央Scotomas的低视率受试者中 黄斑病，主要是与年龄相关的大肿瘤。 确定 正常外周视觉阅读的局限性，正常 观察者将在人工scotoma存在下阅读文本 用双purkinje眼痕稳定在视网膜上。 自从 不适当的眼睛运动可能严重限制外围阅读， 我们还将通过介绍文本一个来研究阅读表现 一次在固定的视网膜位置单词。 这项技术，已知 作为快速的串行视觉呈现或RSVP，实际上消除了 需要眼球运动。 我们将确定程度 低视力主体的外围视网膜的行为像 正常的外围视网膜。 我们将测量空间阶段或 使用相位歧视和游标任务的位置灵敏度。 横向产生（“拥挤”）效果将由 在存在或不存在侧翼的情况下测量字母识别 图案和metaconcontrast掩盖（向后和向前掩蔽 在时间域中）将通过单词识别来测量 范例。 空间不足采样将通过比较 光栅斑块的检测和方向区分，以及 时间不足采样将通过与两种CFF进行比较来评估 脉搏歧视。 在每种情况下，我们都会比较性能 患有中央Scotomas的低视频受试者的正常受试者 使用眼球控制的受试者受控的外围观察。 我们将 确定低视觉阅读能力与大小的关系 中央Scotomas的位置和密度以及任何发现的 外周视觉功能异常。 给出更好的 了解外围阅读的视觉限制 性能，我们将研究增强或 修改图像以提高性能。 我们将 探索非线性放大倍率并增加字母间距 克服拥挤问题，低通的空间和时间过滤 减少横向和元对比较掩盖，并使用静态 和动态纹理以改善字母分离。