INFANT VISUAL SENSITIVITY AND SPATIAL VISION

描述：3个月大婴儿的游标视力差50-150倍 而分辨率仅为成人的10倍左右 更糟。游标敏锐度是衡量精细空间定位的指标 除了简单的检测之外，还需要额外的感知处理 刺激物。这项研究项目的总体目标是 了解婴儿和成人之间的哪些差异是关键 限制婴儿游标敏锐度的不成熟和不成熟。这些 不成熟可分为两类：那些导致贫穷的人 视觉敏感度和空间视觉特有的敏感度。视觉 敏感度。当游标刺激被设计成“使比赛变得平坦”时 通过对婴儿和成年人同样可见的领域，是婴儿和 成人游标敏锐度相似吗？在实验I、II和III中，刺激 将由同样可见的傅里叶分量创建 婴儿和成年人。这将通过应用组合来实现 模糊，对比度降低，并给成年人增加了“白”噪音 刺激物。如果这些手法将成人的游标敏锐度带入 婴儿范围，这将表明婴儿较差的游标敏锐度是由于 他们的视觉麻木不仁。在实验四中，游标敏锐度将是 研究中使用了正弦刺激和三角分析。如果 婴儿和成人的游标敏锐度可以从他们的对比中预测出来 辨别表演，那将是视觉上的证据 不敏感是婴儿游标敏锐度差的原因。这 分析也将应用于成人弱视，以找出是否 斜视性和屈光参差性弱视是由视觉障碍引起的 发展。空间视觉。如果仅凭视觉不敏感就不能 解释婴儿游标敏锐度差的原因是什么？ 额外的未到期债务？在实验V中，空间不确定性或 视觉处理阶段之间视网膜定位图的加扰 将通过检测婴儿对“白色”亮度的敏感度进行比较 噪声和位置噪声添加到游标刺激中。位置 噪声是通过随机抖动空间位置引入的 刺激中的像素。如果位置噪声对 比亮度噪声更敏锐，这将是证据 空间不确定性是游标敏锐度差的部分原因 婴儿的数量。在实验六中，游标的偏移量 刺激措施将被一道缺口隔开。宽度的临界值 将与固有模糊量进行比较 实验一以确定婴儿的视觉表征是否 游标刺激的样本严重不足。临床相关性。 在这个基础科学项目的过程中，PI将发现 正常婴儿游标视力是否只因差而差 视觉敏感度还是像斜视性弱视一样，婴儿也 在他们的空间视觉上有重要的不成熟。如果正常的婴儿 表现得像正常成年人，那么游标敏锐度任务很可能是 有助于诊断婴儿期弱视；如果婴儿表现正常 像成人斜视性弱视一样，游标敏锐度的临床测试是 不太可能是有用的。

DESCRIPTION: The vernier acuity of 3-month-olds is 50-150 times worse than that of adults, whereas resolution acuity is only about 10 times worse. Vernier acuity is a measure of fine spatial localization that requires additional perceptual processing beyond the simple detection of the stimuli. The overall goal of this research project is to understand which differences between infants and adults are critical immaturities that limit infant vernier acuity and which are not. These immaturities may be divided into two groups: those that lead to poor visual sensitivity and those that are specific to spatial vision. Visual sensitivity. When vernier stimuli are designed to "level the playing field" by being equally visible to infants and adults, are infant and adult vernier acuities similar? In Experiments I, II, and III, stimuli will be created from Fourier components that are equally visible to infants and adults. This will be accomplished by applying a combination of blur, contrast reduction, and added "white" noise to the adult stimuli. If these manipulations bring adult vernier acuity into the infant range, this will suggest that infants' poor vernier acuity is due to their visual insensitivity. In Experiment IV, vernier acuity will be studied using a sinusoidal stimuli and a trigonometric analysis. If infant and adult vernier acuity can be predicted from their contrast discrimination performance, that will be evidence that visual insensitivity is responsible for infants' poor vernier acuity. This analysis will also be applied to adult amblyopes to find out whether strabismic and anisometropic amblyopia are caused by an arrest of visual development. Spatial vision. If visual insensitivity alone cannot explain infants' poor vernier acuity, what is the nature of the additional immaturities? In Experiment V, spatial uncertainty or scrambling of the retinotopic map between stages of visual processing will be compared by examining infant sensitivity to "white" luminance noise and positional noise added to the vernier stimulus. Positional noise is introduced by randomly jittering the spatial positions of pixels in the stimulus. If positional noise has a bigger effect on vernier acuity than luminance noise does, that will be evidence that spatial uncertainty is partly responsible for the poor vernier acuity of infants. In Experiment VI, the offset segments of the vernier stimulus will be separated by a gap. The critical value of the width of that gap will be compared to the amount of intrinsic blur from Experiment I to determine whether the infant's visual representation of the vernier stimulus is significantly undersampled. Clinical relevance. In the course of this basic-science project, the PI will find out whether normal infant vernier acuity is poor simply because of poor visual sensitivity or whether, like strabismic amblyopes, infants also have important immaturities in their spatial vision. If normal infants behave like normal adults then a vernier acuity task is likely to be useful for diagnosing amblyopia in infancy; if normal infants behave like adult strabismic amblyopes, a clinical test of vernier acuity is less likely to be useful.