Neural Development of Lexical Processing

描述（由申请人提供）：我们已经制定了一个发展神经认知模型的词汇处理在正常读者的基础上横截面功能磁共振成像（fMRI）的数据，我们已经收集了我们的第一个纵向数据对这些儿童2年后，他们的初步评估。拟议的补助金将纵向跟踪正常儿童（7至17岁）和阅读障碍儿童（11至15岁），当他们执行各种任务。这些任务包括在视觉和听觉模式中的拼写（拼写）、语音（押韵）和语义（意义）判断。这个建议不仅是创新的，因为我们使用了各种各样的任务，但我们也有多个知觉控制和多个参数操作的难度，所以我们可以更有效地检查特定的词汇处理方面的发展和群体效应。此外，我们的范式允许检查启动和词汇的影响（如词频，语音的一致性和拼写的一致性），所以观察到的发展和组的差异是不太可能是由于任务的具体特点。本研究的总体目标是确定不同的群体是否有不同的发展轨迹。纵向设计是至关重要的，以排除队列效应，并检查个人的后续大脑发育的可预测性，从他们早期的阅读技能和大脑激活模式。除了检查是否较高和较低的技能正常的读者有不同的发展轨迹，我们将检查是否有特定的赤字解码正字法刺激的阅读障碍的读者有不同的发展轨迹，从语言受损的读者与赤字解码正字法刺激，除了一般的语言处理缺陷。我们还将比较患有障碍的儿童与年龄匹配与阅读匹配的正常读者，以解决发展迟缓与偏差的问题。我们的一般假设是，读者之间大脑激活的个体差异会随着年龄的增长而增加。这将使用分层线性模型进行测试，以检查变化率（例如斜率）和变化形状（例如加速度）的生长曲线。我们将使用这种技术来观察我们感兴趣的关键区域中信号强度的发育变化，以及使用动态因果模型（DCM）的有效连接变化。公共卫生相关性本提案将为我们提供有关典型儿童的大脑在整个童年和青春期阅读和语言处理过程中如何变化的基本信息，以及患有阅读和语言障碍的儿童的大脑在发育过程中如何不同的基本信息。这笔赠款与生物医学问题的相关性在于，它对患有阅读和语言障碍的儿童的诊断和干预具有影响。

DESCRIPTION (provided by applicant): We have formulated a developmental neuro-cognitive model of lexical processing in normal readers based on cross-sectional functional magnetic resonance imaging (fMRI) data and we have collected our first longitudinal data on these children 2 years after their initial assessment. The proposed grant will longitudinally follow normal children (7- to 17- year-olds) and children with reading disorders (11- to 15-year-olds) when they perform a variety of tasks. These tasks include orthographic (spelling), phonological (rhyming) and semantic (meaning) judgments in the visual and auditory modalities. Not only is this proposal innovative because we use a variety of tasks, but we also have multiple perceptual controls and multiple parametric manipulations of difficulty, so we can more effectively examine developmental and group effects specific to aspects of lexical processing. Furthermore, our paradigms allow an examination of priming and lexical effects (e.g. word frequency, phonological consistency and orthographic consistency) so observed developmental and group differences are not likely to be due to specific characteristics of the tasks. The overall aim of this study is to determine whether different groups have different developmental trajectories. A longitudinal design is crucial to rule out cohort effects and to examine the predictability of the individual's subsequent brain development from their earlier reading skill and brain activation patterns. In addition to examining whether higher and lower skill normal readers have different developmental trajectories, we will examine whether dyslexic readers with specific deficits in decoding orthographic stimuli have different developmental trajectories from language-impaired readers with deficits in decoding orthographic stimuli in addition to general language processing deficits. We will also compare children with disorders to age-match versus reading-match normal readers to address the question of developmental delay versus deviance. Our general hypothesis is that individual differences in brain activation between readers will increase with age. This will be tested using hierarchical linear modeling to examine growth curves in the rate of change (e.g. slope) and in the shape of change (e.g. acceleration). We will use this technique to look at developmental changes in signal intensity in our critical regions of interest, but also for changes in effective connectivity using Dynamic Causal Modeling (DCM). PUBLIC HEALTH RELEVANCE This proposal will give us basic information about how the brains of typical children change throughout childhood and adolescence during reading and language processing, but also how the brains of children with reading and language disorders differ in their development. The relevance of this grant to biomedical issues is that it has implications for diagnosis and intervention in children with reading and language disorders.