INFANT VISUAL SENSITIVITY AND SPATIAL VISION

描述：3个月大的婴儿的游标敏锐度要差50-150倍 而分辨力只有成人的10倍左右， 糟了 游标敏锐度是精细空间定位的量度， 需要除了简单检测之外的额外感知处理 的刺激。 本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至关重要的 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：导致贫穷的， 视觉敏感度和空间视觉特异性。视觉 灵敏度 当游标刺激被设计成“水平演奏 通过对婴儿和成年人同样可见，”场“是婴儿和 成人游标视力相似？ 在实验I、II和III中，刺激 将从傅立叶分量中创建，这些分量对于 婴儿和成人。 这将通过应用组合 模糊，对比度降低，并添加“白色”噪音的成人 刺激。 如果这些操作将成人的游标敏锐度带入 婴儿范围，这将表明婴儿的游标敏锐度差是由于 他们的视觉迟钝。 在实验IV中，游标敏锐度将是 使用正弦刺激和三角分析进行研究。 如果 婴儿和成人游标敏锐度可以从他们的对比度来预测 辨别力的表现，这将是证据， 不敏感是婴儿游标敏锐度差的原因。 这 分析也将适用于成人弱视，以找出是否 斜视和屈光参差性弱视是由视觉障碍引起的， 发展空间视觉。 如果光是视觉不敏感 解释婴儿的游标敏锐度差，是什么性质的， 额外的未到期？ 在实验V中，空间不确定性或 视觉处理各阶段之间视网膜位置图的混乱 将通过检查婴儿对“白色”亮度的敏感性进行比较 噪声和位置噪声添加到游标刺激。 位置 通过随机抖动的空间位置来引入噪声 刺激中的像素。 如果位置噪声对 游标敏锐度比亮度噪声，这将是证据， 空间不确定性是造成游标敏锐度差的部分原因 的婴儿。 在实验VI中，游标的偏移段 刺激将由间隙分开。 宽度临界值 该间隙的大小将与来自 实验一，以确定是否婴儿的视觉表征， 游标激励被显著欠采样。临床相关性。 在这个基础科学项目中，私家侦探会发现 正常婴儿游标视力差是否仅仅是因为 视觉敏感度，或者像斜视性弱视一样， 在空间视觉上有很大的不成熟。 如果正常的婴儿 像正常成年人一样行事，那么游标敏锐度任务可能是 用于诊断婴儿期弱视;如果正常婴儿表现 与成人斜视性弱视一样， 不太可能有用。

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.