Effects of Biological Maturation and Visual Experience on Human Visual Developmen

摘要 视觉发育的程度取决于 性质 vs. 培育 由来已久 视觉研究的主题。尽管在过去的50年里，我们从动物研究中学到了很多东西， 对影响人类视觉发育的因素知之甚少。目前的建议调查 是否与视觉体验相关的因素（培育）与预编程生物成熟（性质），或者 两者都对塑造视觉发展很重要。为此，我们建议视觉心理物理研究， 四个不同的受试者群体来区分这些因素。(A)足月婴儿和（B）健康早产儿 婴儿。如果早期的视觉经验是视觉发育的主导力量，早产儿应该表现出 以出生后年龄（即自出生以来的年龄）绘制的发育轨迹与足月婴儿相同。 相比之下，如果生物成熟更有影响力，早产儿应该匹配足月婴儿， 在受孕后年龄中绘制（即，自怀孕以来）。(C)同卵双胞胎与异卵双胞胎。虽然这两 虽然双胞胎有着相同的环境和父母，但他们在基因组成上的共享程度不同。我们 应用生物统计学双胞胎模型，可以识别 表型 视觉表现差异 这可以通过共享环境和基因来解释。(D)婴儿和儿童早期异常 视觉输入。这组（白内障、斜视和屈光参差）与健康人之间的比较 控制将解决视觉处理的各个方面对异常视觉体验的脆弱性 早期发展。三个目标针对不同层次的视觉处理：1）皮层下通路 处理：我们询问是否三个主要的视网膜神经通路，大细胞（M），小细胞（P）和 Koniocellular（K）通过获得对比敏感度，受到视觉体验的同等或不同影响 对于亮度，红色/绿色和蓝色/黄色刺激，认为分别由这些途径介导。（二） 皮层运动处理的皮层下输入：我们将获得皮层下P与M的范围估计值 路径输入到运动处理， 运动/检测 阈值比率范式， 色度（P通路）对比亮度（M通路）对比度对运动处理的相对影响。先前 我们实验室的结果表明，运动的相对P与M输入随着年龄的增长而减少，在这里，我们 将问这个重新加权过程是否受视觉经验或生物成熟的影响更大。第三章 皮层运动处理：我们将评估全局运动处理，这被认为是一个更高的水平 皮质功能与许多以前的研究不同，我们的全局运动刺激将被缩放到每个 受试者，以便可以更明确地解释在年龄/受试者组之间观察到的差异。的 这些项目的结果，这将揭示哪些方面的视觉发展是更多与更少的服从 视觉体验的影响，可能对治疗先天性眼病儿童具有重要意义 紊乱 1叙述： 视觉发育的程度取决于 性质 (i.e.,预编程生物学 成熟）与 培育 (i.e.,视觉体验）一直是视觉研究中的一个长期课题。的 目前的建议是通过在受试者中进行婴儿视觉心理物理研究来调查这个问题。 具有相关性的人群：早产儿、双胞胎婴儿和先天性眼病婴儿。 这些研究的结果，我们希望能揭示哪些方面的视觉发展是多与少 服从视觉经验的影响，可能有重要的意义，为治疗儿童的视觉 紊乱 2

ABSTRACT The degree to which visual development is governed by nature vs. nurture has been a long-standing topic in vision research. Although much has been learned from animal studies in the last 50 years, relatively little is known about the factors influencing visual development in humans. The current proposal investigates whether factors related to visual experience (nurture) vs. preprogrammed biological maturation (nature), or both, are important in shaping visual development. To this end, we propose visual psychophysical studies with four different subject populations that tease apart these factors. (A) Fullterm Infants and (B) Healthy Preterm Infants. If early visual experience is the dominant force in visual development, preterm infants should show the same developmental trajectories as fullterm infants when plotted in terms of postnatal age (i.e. age since birth). By contrast, if biological maturation is more influential, preterm infants should match fullterm babies when plotted in postconceptional age (i.e., age since conception). (C) Monozygotic vs. Dizygotic Twins. While both twin types share the same environment and parents, they differ in the degree of shared genetic makeup. We apply a biometrical twin model that can identify the proportion of phenotypic variance in visual performance that can be accounted for by shared environment versus genes. (D) Infants and Children with Early Abnormal Visual Input. Comparisons made between this group (cataract, strabismus, and anisometropia) and healthy controls will address the vulnerability of various aspects of visual processing to abnormal visual experience early in development. Three aims address different levels of visual processing: 1) Subcortical Pathway Processing: We ask if the three main retinogeniculate pathways, Magnocellular (M), Parvocellular (P) and Koniocellular (K), are equally or differentially affected by visual experience, by obtaining contrast sensitivities for luminance, red/green and blue/yellow stimuli, thought to be mediated by these pathways, respectively. 2) Subcortical Input to Cortical Motion Processing: We will obtain an estimate of the extent of P vs. M subcortical pathway input to motion processing using a Motion/Detection threshold ratio paradigm that measures the relative effects of chromatic (P pathway) vs. luminance (M pathway) contrast on motion processing. Previous results from our laboratory suggest that the relative P vs. M input to motion decreases with age, and here we will ask whether this re-weighting process is influenced more by visual experience or biological maturation. 3) Cortical Motion Processing: We will assess global motion processing, which is believed to be a higher-level cortical function. Unlike many previous studies, our global motion stimuli will be scaled to detectability for each subject, such that differences observed across ages/subject groups can be more definitively interpreted. The results of these projects, which will reveal what aspects of visual development are more vs. less amenable to effects of visual experience, may have important implications for treating children with congenital eye disorders. 1 NARRATIVE: The degree to which visual development is governed by nature (i.e., pre-programmed biological maturation) vs. nurture (i.e., visual experience) has been a long-standing topic in vision research. The current proposal investigates this question by conducting infant visual psychophysical studies in subject populations that bear relevance: preterm infants, twin infants and infants born with congenital eye disorders. The results of these studies, which we hope will reveal what aspects of visual development are more vs. less amenable to effects of visual experience, may have important implications for treating children with visual disorders. 2