BRAIN ASYMMETRY AND LANGUAGE DEVELOPMENT

人脑在功能和解剖学上都是偏侧化的。在大多数 成年人，语言局限于左半球，而空间和空间 情绪功能局限于右半球。向左 颞平面(韦尼克区)和三角部的不对称性 (布罗卡区)被认为是这一现象的神经生物学底物 功能偏侧化。在儿童时期，功能偏侧化 变得不可逆转。40名正常儿童的试验数据表明 大脑不对称性的发育变化发生在这一时期。 这个项目试图确认这些变化并探索它们之间的关系 不对称与语言技能发展之间的关系。这项研究将 提供正常脑形态测量的数据基础，如 在儿童磁共振成像(MRI)扫描中可视化 在5岁到10岁之间。主要目标是确定 是否(1)前后部语言的体积不对称 区域在此期间发生变化；(2)平面不对称性预测技能 音素意识、阅读和拼写；(3)三角区 不对称性预示着口语表达能力和流利性。在……里面 此外，结构的体积变化不被认为是主要的 参与语言发展的脑区--胼胝体、尾状核 和海马体，将被测量以检查 调查结果。 一组100名受试者，年龄从5岁6个月到7岁6个月， 正常智商的人将得到一份语言史调查问卷和一份 神经语言学组件，包括音素意识、阅读和 口头语言。受试者群体将在性别和惯用手方面取得平衡。 受试者将接受头部的MRI扫描，这提供了一种无缝的 一系列薄的矢状面。基于计算机的体积测量 将由Wernicke区的颞平面三角部构成 在Broca区，海马体和尾状核。十字架- 膝部、体部、峡部和压部的截面积 同时还将测量骨痂和总的颅内体积。 两年后，这些儿童将再次接受检测和扫描。基于 根据之前的工作和试点数据，预计(1) 伴随着发育的是颞平面的向左不对称 提高音素意识、阅读和拼写能力；(2)右旋 儿童三角部的向左不对称性比 (3)表达能力好的孩子会有更大的 三角部不对称。这一结果应该会为 儿童正常语言发育的神经元底物和提供 一个与语言中的大脑结构进行比较的正常数据库 而学习障碍的孩子也可以。该数据还将使 准确绘制语言区域图，以便与脑电和其他 儿童的功能研究。

The human brain is functionally and anatomically lateralized. In most adults, language is localized in the left hemisphere while spatial and emotional functions are localized in the right hemisphere. Leftward asymmetry of the planum temporale (Wernicke's area) and pars triangularis (Broca's area) are believed to be the neurobiological substrate of this functional lateralization. During childhood, functional lateralization becomes irreversible. Pilot data in 40 normal children suggest that developmental changes in cerebral asymmetry occur during this period. This project seeks to confirm those changes and to explore the relation between asymmetry and the development of language skills. The study will provide a data base of measurements of normal cerebral morphology as visualized in the magnetic resonance imaging (MRI) scans of children between the ages of 5 and 10. The major objectives are to determine whether (1) volumetric asymmetries of the anterior and posterior language regions change during this period; (2) planar asymmetry predicts skill in phonemic awareness, reading and spelling; and (3) pars triangularis asymmetry predicts skills in expressive oral language and fluency. In addition, volumetric changes in structures not thought to be primarily involved in language development -- the corpus callosum, caudate nucleus and the hippocampus, will be measured to examine the specificity of the findings. A group of 100 subjects, aged 5 years 6 months to 7 years 6 months, with normal IQs, will be given a language history questionnaire and a neurolinguistic battery including tests of phonemic awareness, reading and oral language. The subject group will be balanced for sex and handedness. The subjects will receive MRI scan of the head that provides a gapless series of thin sagittal sections. Computer based volumetric measurements will be made of the planum temporale in Wernicke's area, pars triangularis in Broca's area, the hippocampus, and the caudate nucleus. The cross- sectional area of the genu, body, isthmus, and splenium of the corpus callosum and the total intracranial volume will also be measured. The children will be tested and scanned again two years later. Based on previous work as well as pilot data it is predicted (1) that increases in leftward asymmetry of the planum temporale will accompany developmental improvements in phonemic awareness, reading and spelling; (2) dextral children will have greater leftward asymmetry of pars triangularis than adextrals; (3) children with good expressive skills will have greater asymmetry of pars triangularis. The results should shed light on the neuronal substrate of normal language development in childhood and provide a normal database from which comparisons to brain structures in language and learning impaired children can be made. The data will also enable the accurate mapping of language areas for correlation with EEG and other functional studies in children.