FMRI OF NORMAL LANGUAGE DEVELOPMENT IN CHILDREN

人类语言发展的研究已经用行为方法进行了几十年，但这一主要儿童成就的神经生物学基础还没有得到很好的理解。在整个正常发育过程中绘制语言在大脑中的功能分布图，可以为了解正常语言习得和儿童语言障碍的本质提供相当大的见解。在临床上，语言是发育性或获得性小儿神经障碍的最早标志之一。在儿童中，语言功能障碍的评估也必须考虑到可能存在的正常发育变化。功能磁共振成像（fMRI）为语言发展研究提供了一种无创技术。虽然功能磁共振成像已被用于检查成人的语言和语言病理，但这项技术在儿童中的应用却有限。这部分是由于fMRI固有的低信噪比和对运动的敏感性。然而，通过使用3特斯拉核磁共振扫描仪和经验丰富的儿科神经成像团队，我们能够在5岁以下的儿童中常规获得高质量的功能磁共振成像语言图。我们建议使用3特斯拉的功能磁共振成像技术来绘制5至18岁儿童正常语言发展的具体方面。我们将研究四项旨在跨越语言发展进程的语言任务：其中两项是在学龄前获得的挖掘技能，另两项是在上学期间继续发展的挖掘技能。这些技能领域的规范语言地图将从5岁至18岁的10名男孩和10名女孩（N=280名正常受试者）的复合功能磁共振成像数据中构建。这些地图的变化将被认为与受试者的年龄和语言技能水平有关（通过标准化测试来衡量）。最后，通过将正常语言数据与20名因围产期大脑中动脉中风而导致语言能力受损的患者的数据进行比较，评估正常语言数据的效用。本项目将为语言功能磁共振成像研究建立规范性数据，为广泛的儿童神经系统疾病研究提供参考。

Human language development has been studied using behavioral methods for decades, yet the neurobiologic basis of this major childhood accomplishment is not well understood. Mapping the functional distribution of language in the brain throughout normal development could provide considerable insight into the nature of both normal language acquisition and disorders that disrupt language in pediatric populations. Clinically, language is one of the earliest markers for developmental or acquired pediatric neurologic disorders. In children, assessment of language dysfunction must also take into account normal developmental changes that may exist. Functional magnetic resonance imaging (fMRI) offers a noninvasive technique which could be applied to the study of language development. Whereas fMRI has been used to examine language and language pathology in adults, applications of this technology in children have been limited. This is due in part to the inherently low signal-to- noise ratio and sensitivity to motion of fMRI. However, with the use of a 3 Tesla MRI scanner and an experienced pediatric neuroimaging team, we are able to routinely obtain high quality fMRI language maps in children as young as five years of age. We propose to use fMRI techniques at 3 Tesla to map specific aspects of normal language development in children from ages 5 to 18. We will examine four language tasks designed to span the progression of language development: two of which tap skills acquired during the preschool years and two of which tap skills that continue to develop into the school years. Normative language maps for each of these skill domains will be constructed from composite fMRI data from 10 boys and 10 girls at each year of age from 5 through 18 (N=280 normal subjects). Variations in these maps will be considered relative to both subject age and level of language skill (as measured by standardized testing). Finally, the utility of the normal language data will be evaluated by comparing it against data obtained from a group of 20 patients with impaired language ability resulting from perinatal stroke in the middle cerebral artery. This project will establish normative data for fMRI studies of language to be used as a reference in studies of a wide range of neurologic disorders in children.