Behavioral Characteristics and Neural Correlates of Reading Impairment in FASD

描述(由申请人提供)：尽管有一些研究证明患有胎儿酒精谱系障碍(FASD)的儿童阅读表现较差，但对可能受到影响的阅读的具体方面知之甚少。在最近的两项研究中，开普敦大学(UCT)的皮雅各布森和她的同事们发现，产前酒精暴露对阅读理解的具体影响是通过阅读流利性和语音意识缺陷来调节的。尽管发展性阅读障碍儿童阅读障碍的神经机制已被广泛研究，但FASD儿童阅读障碍的神经机制尚未被研究过。波士顿儿童医院(BCH)的Pi Gaab等人对DD的研究发现，在额叶下部、后纵隔和两个左半球后部脑区存在形态和功能变化，左侧弓状束(AF)结构完整性较差。将对南非开普敦两个特征良好的纵向队列进行研究--一个由150名青少年组成，另一个由131名学龄前儿童组成。其目的是(1)系统地描述阅读和阅读前技能在FASD中受到影响的具体方面；(2)检查产前酒精暴露与阅读之间的关系可能在多大程度上可归因于与酒精有关的语言技能、执行功能、工作记忆和/或智商的缺陷；(3)检验如下假设，即酒精暴露的青少年的阅读障碍与下额叶、后脑壳旁和左半球后脑区及其包括房颤在内的潜在白质束的结构和功能缺陷有关；(4)检验如下假设，即与DD一样，胎儿在语音处理过程中的酒精相关神经缺陷(用功能磁共振成像测量)和阅读相关脑区的结构变化在阅读开始之前就已经明显存在，并且在学龄前儿童中已经很明显；(5)测试假设，新生儿大脑左侧房颤中较差的白质完整性将预测学龄前胎儿与酒精相关的阅读前缺陷。自1998年以来，皮雅各布森和她在UCT的同事们一直在研究开普敦有色人种(混合血统)社区的FASD，在那里，FASD的发病率是世界上最高的之一。尽管他们和其他人已经对工作记忆、反应抑制、眨眼条件反射和数字加工进行了神经成像研究，但这将是第一次研究FASD阅读障碍的神经相关性。自2004年以来，Pi Gaab一直在研究DD中调节阅读障碍的神经网络的变化。这将是第一次研究环境暴露产生的神经毒性侮辱如何影响调节阅读的结构和功能的大脑网络。这项拟议的研究将显著提高UCT和BCH实验室的研究能力和方向，并可能有助于为美国、南非和世界范围内的这一重大公共卫生问题开发创新的有针对性的干预措施。

DESCRIPTION (provided by applicant): Although a few studies have documented poorer reading performance in children with fetal alcohol spectrum disorders (FASD), relatively little is known about the specific aspects of reading that may be affected. In two recent studies, PI Jacobson and her colleagues at University of Cape Town (UCT) found specific effects of prenatal alcohol exposure on reading comprehension, which were mediated by deficits in reading fluency and phonological awareness. Although the neural mechanisms that underlie reading impairment have been studied extensively in children with developmental dyslexia (DD), the neural correlates of reading impairment in FASD have not previously been investigated. Studies of DD by PI Gaab at Boston Children's Hospital (BCH) and others have revealed morphological and functional alterations in inferior frontal, posterior perisylvian, and two left hemispheric posterior brain regions and poorer structural integrity in the left arcuate fasciculus (AF). Two well-characterized longitudinal cohorts of children with heavy prenatal alcohol exposure and healthy controls in Cape Town, South Africa, will be studied-one comprised of 150 adolescents; the other, of 131 preschool-age children. The aims are (1) To systematically characterize the specific aspects of reading and pre-reading skills that are affected in FASD; (2) To examine the degree to which the relation between prenatal alcohol exposure and reading may be attributable to alcohol-related deficits in language skills, executive function, working memory, and/or IQ; (3) To test the hypothesis that, as in DD, reading impairment in alcohol-exposed adolescents is associated with structural and functional deficits in inferior frontal, posterior perisylvian, and left hemispheric posterior brain regions and their underlying white matter tracts, including the AF; (4) To test the hypothesis that, as in DD, fetal alcohol-related neural deficits during phonological processing (measured using fMRI) and structural alterations in reading-related brain regions predate reading onset and are already evident in preschool children; (5) To test the hypothesis that poorer white matter integrity in the left AF in the newborn brain will predict fetal alcohol-related pre-reading deficits at preschool age. Since 1998, PI Jacobson and her colleagues at UCT have been studying FASD in the Cape Coloured (mixed ancestry) community, in which incidence of FAS is among the highest in the world. Although they and others have conducted neuroimaging studies of working memory, response inhibition, eyeblink conditioning, and number processing, this will be the first study to examine the neural correlates of reading impairment in FASD. Since 2004, PI Gaab has been studying alterations of the neural network that mediates reading impairment in DD. This will be the first study to examine how a neurotoxic insult from an environmental exposure may affect the structural and functional brain networks that mediate reading. The proposed study will significantly enhance the research capability and direction of both the UCT and BCH laboratories and potentially contribute to development of innovative targeted interventions for this major public health problem in the US, South Africa, and worldwide.