PSYCHOPHYSICS OF READING--NORMAL AND LOW VISION

描述(摘录)：有350万美国人患有低血压症 视力障碍，大多数人有阅读困难。黄斑变性是 主要原因，并经常导致中心视力丧失。阅读 中央视野丧失的人的缺陷是一个重大的、未解决的健康问题 这是一个问题，也是本提案的主要焦点。理雅各医生和他的 同事们开发了一种理想的阅读观察者模型，它提供了一种 理解中心场损失如何影响阅读的理论基础。 视觉跨度的概念在模型中起着关键作用。视觉效果 Span是一次一目了然的字母数 阅读。正常的视觉范围被限制在大约10个字母的宽度内。 因此，这种小的视觉范围会进一步缩小或扭曲 眼疾的症状。这一提议背后的主要假设是 视觉范围的属性可以解释大部分(甚至全部) 无法解释的中央视野丢失造成的阅读缺陷。在四个系列中 实验中，莱格博士建议测试特定的假说， 阅读障碍与(I)字母的时空特征 跨视觉广度的识别；(Ii)字母在 视觉跨度；(3)视觉跨度的整体属性(形状和大小)； 以及(4)语言和动作限制的影响。这项研究 该计划还包括开发两种新的临床测试，其中一种用于评估 对比阅读中的缺陷，以及测量盲文阅读 速度。

DESCRIPTION (from abstract): There are 3.5 million Americans with low vision, most of whom have reading difficulty. Macular degeneration is the leading cause, and often results in a loss of central vision. The reading deficits of people with central-field loss is a major, unsolved health problem, and is the primary focus of this proposal. Dr. Legge and his colleagues have developed an ideal-observer model of reading that provides a theoretical basis for understanding how central-field loss affects reading. The concept of the visual span plays a key role in the model. The visual span is the number of letters that are identified in a single glance during reading. The normal visual span is limited to about 10 letters in width. This small visual span is further diminished or distorted as a consequence of eye disease. The main hypothesis underlying this proposal is that the properties of the visual span can account for much (and perhaps all) of the unexplained reading deficits from central-field loss. In four series of experiments, Dr. Legge proposes to test specific hypotheses that account for reading deficits in terms of (i) spatiotemporal properties of letter recognition across the visual span; (ii) letter interactions within the visual span; (iii) global properties of the visual span (shape and size); and (iv) the influence of linguistic and motor constraints. The research plan also includes development of two new clinical tests, one for assessing contrast deficits in reading, and the other for measuring Braille reading speed.