EFFECTS OF CONTRAST ON PERCEPTION IN DISABLED READERS

最近对阅读障碍儿童的实验表明， 模糊结果在搜索性能，眼睛， 动作模式和阅读理解。 这表明 视觉刺激的对比度和空间频率内容是重要的 这些孩子的因素。 拟议的研究将评估 对比度和空间频率含量对视觉加工的影响 正常和残疾读者。 正常和阅读障碍儿童将 通过使用单独管理的阅读测试进行分类。 他们还将接受一系列筛选测试，包括视觉， 听觉、智力和神经心理学评估， 他们的整体地位。 孩子们将参加一个实验 设计用于测量空间滤波和对比度的效果 减少视觉搜索。 该实验将提供以下信息 是否出现了先前证明的对比度降低的益处 对于所有的空间频率，或者被限制在有限的范围内， 空间频率 在第二个实验中，使用同样的孩子， 与不同空间频率相关联的对比度增益将 使用对比度匹配范例进行评估。 这个实验将允许 对第一个实验进行更精确的解释，并提供 对对比度重要的对比度范围信息 减少效应。 在第三个实验中，孩子们的运动 将在各种空间频率下测量检测灵敏度。 本实验将确定对比度增益问题是否与 减少了移动检测。 第四个实验将检验 利用不同对比度目标的空间定位能力。 这 实验将确定对比度增益问题是否与 先前报道的空间位置差异在穷人的读者。 的 这四个实验的结果将提供有价值的信息， 阅读障碍儿童视力缺陷的性质， 阐明现有补救技术所涉及的主要因素。

Recent experiments with reading disabled children have shown that image blurring results in an immediate benefit in search performance, eye movement pattern and reading comprehension. This suggests that the contrast and spatial frequency content of visual stimuli are important factors for these children. The proposed research will assess the effects of contrast and spatial frequency content on visual processing in normal and disabled readers. Normal and reading disabled children will be classified through the use of individually administered reading tests. They will also undergo a battery of screening tests involving visual, auditory, intellectual, and neuropsychological assessment to evaluate their overall status. The children will take part in an experiment designed to measure the effects of spatial filtering and contrast reduction on visual search. This experiment will provide information on whether the previously demonstrated benefit of contrast reduction occurs for all spatial frequencies or is restricted to a limited range of spatial frequencies. In a second experiment using the same children, the contrast gain associated with different spatial frequencies will be assessed using a contrast matching paradigm. This experiment will allow a more precise interpretation of the first experiment and provide information on the range of contrasts that are important for contrast reduction effects. In the third experiment, the children's movement detection sensitivity will be measured at various spatial frequencies. This experiment will determine if contrast gain problems are associated with decreased movement detection. The fourth experiment will examine spatial location ability using targets of different contrast. This experiment will determine if contrast gain problems are associated with previously reported spatial location discrepancies in poor readers. The results of these four experiments will provide valuable information about the nature of the visual deficit in reading disabled children and elucidate the major factors involved in existing remedial techniques.