Predicting language processing efficiency in preterm children: Social-environmental and neuro-biological factors

在美国，每年都有超过十分之一的儿童早产。大约一半的非常 早产儿，在怀孕32周时出生，会出现基于语言的学习障碍，可能是 发现较晚，并使儿童在一生中面临不良结局的巨大风险。我们之前的拨款 (HD069150)令人信服地证明了在18个月的眼睛中评估的语言处理效率- 被称为边看边听(LWL)的跟踪范式比 标准化测试和家长报告。18个月时语言处理速度较快的PT儿童 54个月时在语言和非语言技能方面都显示出优势。我们的下一步是及早了解 普通话水平儿童语言加工效率的预测因素在这次更新中，我们招募了PT新生儿(n=140)。 来自两个语言群体，主要是英语-主要是西班牙语家庭，以增加我们的多样性 样本，以提高泛化能力。我们在12个月(婴儿)时评估社会环境预测因素 环境)和18个月(幼儿环境)，使用儿童语言的全天录音 照顾者与儿童相互作用的环境和自然主义实验室观察。我们评估神经生物学 新生儿时期(新生儿扫描)和12个月的脑白质微结构预测指标 (婴儿扫描)。我们使用两种互补类型的MRI扫描来评估白质轴突属性和 髓鞘含量。在18个月时，主要的结果测量是LWL任务中的语言处理速度， 儿童将视线转移到一个刚命名的物体的图片上所花费的时间。的父级报告 词汇和语言发展标准化测试的分数是次要的衡量标准。我们的目标 目的是：(1)确定婴儿和/或蹒跚学步儿童的环境特性是否能预测语言处理速度 以及两种语言组的PT儿童的次要结局；(2)确定白人的特征 从新生儿和/或婴儿核磁共振扫描中评估的物质通路，可以预测语言处理速度和 二次结果，在考虑了语言组、临床变量和其他协变量后；以及(3) 探讨社会环境因素和脑白质发育对语言的影响 处理速度在这个不同的样本中出生的儿童PT。我们的主要假设是 语言学习环境和语言处理速度受脑白质变化的影响 发展，这表明支持性学习环境会影响语言结果，因为学习 环境促进了白质微结构的发展。证明了白质 变化中介社会-环境因素对语言结果的关联提供了一个明确的 人类大脑中依赖经验的可塑性的例子。这一发现代表了一种理论上的 为不同语言群体的PT儿童的学习和发展模式做出贡献，并将为 对语言预后不良的高危PT儿童的临床实践和早期干预。

Each year in the U.S., more than one in 10 children are born preterm (PT). Approximately half of very preterm survivors, born at < 32 weeks’ gestation, develop language-based learning impairments that may be discovered late and put children at substantial risk for poor outcomes throughout their lives. Our previous grant (HD069150) convincingly demonstrated that language processing efficiency, assessed at 18 months in an eye- tracking paradigm, called looking-while-listening (LWL), was more predictive of long-term outcomes than standardized tests and parent reports. PT children who were faster at language processing at 18 months showed advantages in both verbal and non-verbal skills at 54 months. Our next step is to understand early predictors of language processing efficiency in PT children. In this renewal, we enroll PT neonates (n = 140) from two language groups, primarily English- and primarily Spanish families, to increase the diversity of our sample and to improve generalizability. We assess social-environmental predictors at 12 months (infant environment) and 18 months (toddler environment) using day-long audio recordings of the child’s language environment and naturalistic laboratory observations of caregiver-child interactions. We assess neurobiological predictors, focusing on white matter microstructure, in the neonatal period (neonatal scans) and at 12 months (infant scans). We use two complementary types of MRI scans to assess white matter axonal properties and myelin content. At 18 months, the primary outcome measure is language processing speed in the LWL task, the time it takes the child to shift eye gaze to the picture of an object that was just named. Parent reports of vocabulary and scores on a standardized test of language development are secondary measures. Our aims are to: (1) determine if properties of the infant and/or toddler environments predict language processing speed and secondary outcomes in PT children from the two language-groups; (2) determine if properties of white matter pathways, assessed from neonatal and/or infant MRI scans, predict language processing speed and secondary outcomes, after consideration of language group, clinical variables, and other covariates; and (3) investigate the contributions of social-environmental factors and white matter development on language processing speed in this diverse sample of children born PT. Our main hypothesis is that relations between language learning environments and language processing speed are mediated by changes in white matter development, suggesting that supportive learning environments impact language outcomes because learning environments advance the development of white matter microstructure. The demonstration that white matter change mediates the association of social-environmental factors on language outcomes provides a clear example of experience-dependent plasticity in the human brain. This finding would represent a theoretical contribution to models of learning and development in PT children across language groups and would inform clinical practice and early intervention for PT children who are at high risk for poor language outcomes.