Orthographic and phonological selectivity in dyslexia: an fMRI study

阅读障碍的拼写和语音选择性：一项功能磁共振成像研究

• 批准号: 8239936
• 负责人: Guinevere F. Eden
• 金额: $ 19.01万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-07 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8239936
• 关键词: Address; Adult; Affect; Area; Behavior; Behavioral; Brain; Brain imaging; Brain region; Code; Cognitive; Cognitive deficits; Developmental reading disorder; Dorsal; Dyslexia; Financial compensation; Functional Magnetic Resonance Imaging; Future; Goals; Hyperactive behavior; Imaging Techniques; Imaging problem; Imaging technology; Impairment; Individual; Inferior frontal gyrus; Intervention; Investigation; Lead; Learning; Left; Link; Measures; Mediating; Methods; Neurons; Orthography; Parietal; Parietal Lobe; Pathway interactions; Performance; Physiological; Population; Process; Reader; Reading; Reading Disabilities; Reading Disorder; Relative (related person); Reporting; Research; Semantics; Signal Transduction; Societies; Specificity; Stimulus; Stream; System; Techniques; Testing; Time; Visual; Visual Pathways; base; density; design; experience; imaging modality; insight; interest; literate; novel; paired stimuli; phonology; public health relevance; relating to nervous system; remediation; response; skills; theories; time use; university student

DESCRIPTION (provided by applicant): Reading is paramount in our literate society; unfortunately it does not come easily to 5-12% of the population who suffer the heritable condition of developmental dyslexia, a reading difficulty unexpected in relation to other cognitive abilities and the provision of educational opportunities. Modern imaging technology has demonstrated that typical readers rely on two left-lateralized pathways: A dorsal circuit mediating phonological processing and a ventral, visual pathway, including the "visual word form area", VWFA, specialized for the fast recognition of single words. How these pathways are affected in dyslexia, has been a topic of intense research. Most current theories posit a weakness in phonological processing as the primary problem and imaging studies have revealed physiological and anatomical differences in left parietal cortex when comparing dyslexic and non- dyslexic readers. At the same time, there are many reports of decreased activity in the ventral visual pathway, which represents another important part of the reading system leading to semantic access. The application's long-term objective is to employ a novel technical approach that will lead to better characterization of the neural bases of both these ventral and dorsal streams and differences in dyslexia. To date, functional magnetic resonance imaging (fMRI) technology has been limited by the fact that the density of selective neurons as well as the broadness of their tuning contributes to the average activity measured. FMRI rapid adaptation (fMRI- RA), however, probes neuronal selectivity more directly and allows a better characterization of neuron-level processing and its link to behavior. This is critical if we are to understand findings about hypo- and hyper- activity reported in various regions of the brain in current studies of dyslexia, as the interpretation of these results has been somewhat limited. Specifically, the project will examine selectivity differences in phonological and orthographic representations in dyslexic relative to typical readers by comparing adults with and without dyslexia. The study will first test the hypothesis that adults with dyslexia who have normal real word reading skills (albeit poor pseudoword reading) show normal selectivity for real words in their VWFA (preserved left VWFA or right VWFA compensation), while those dyslexics with poor real word reading skills do not; and that real word reading ability correlates with selectivity in the VWFA (Aim 1). Secondly, the study will test the hypothesis that adults with dyslexia, due to their weaknesses in phonological coding, show less selectivity for phonological processing in left parietal cortex than typical readers, and that pseudoword reading ability correlates with parietal selectivity (Aim 2). These studies will make it possible, for the first time, to gauge specificity of brain activity in dyslexia rather than simply activation levels. This information is critical if we are to understand the mechanisms that lead to disorders of reading and importantly, guide which interventions should be applied, as current treatments are likely to impact different brain systems. Advancing this field could reduce the number of impaired readers and limit the detrimental educational and vocational consequences of dyslexia. PUBLIC HEALTH RELEVANCE: Developmental dyslexia is a common (5-12% of the population) reading disability, unexpected in relation to other cognitive abilities and the provision of educational opportunities. A new imaging method will be used to better understand the specificity of the brain circuits involved in reading by comparing dyslexic and non- dyslexic college students. The results will advance our understanding of the mechanisms that lead to disorders of reading and potentially guide future interventions, eventually reducing the number of impaired readers and limiting the detrimental educational and vocational consequences of dyslexia.

描述（由申请人提供）：阅读在我们的识字社会中至关重要；不幸的是，有5-12％的人口不容易遭受发育阅读障碍的遗传状况，这是与其他认知能力和提供教育机会有关的阅读困难。现代成像技术表明，典型的读者依赖两种左侧途径：背面介导语音处理和腹侧的视觉途径，包括“视觉单词表单区域”，VWFA，专门针对单个单词的快速识别。这些途径在阅读障碍中如何受到影响，一直是激烈研究的话题。当前的大多数理论认为语音处理中的弱点是主要问题，并且成像研究揭示了比较迟发性和非阅读障碍读物时左边顶皮层的生理和解剖学差异。同时，有许多报道在腹侧视觉途径中活动减少，这代表了阅读系统的另一个重要部分，导致语义访问。该应用程序的长期目标是采用一种新颖的技术方法，该方法将更好地表征这些腹侧和背裂的神经底座以及阅读障碍的差异。迄今为止，功能性磁共振成像（fMRI）技术受到了这样一个事实的限制：选择性神经元的密度以及其调音的宽度有助于测量的平均活性。但是，FMRI快速适应（FMRIA）更直接地探测神经元的选择性，并可以更好地表征神经元级处理及其与行为的联系。如果我们要了解有关当前阅读障碍研究中有关在大脑各个地区报告的低活性和超级活性的发现，这将是至关重要的，因为这些结果的解释受到限制。具体而言，该项目将通过比较患有和没有阅读障碍的成年人，研究阅读障碍相对于典型读者的语音和矫正表达的选择性差异。该研究将首先检验以下假设：患有正常真实单词阅读技能的成年人（尽管较差的伪读）在其VWFA中表现出对真实单词的正常选择性（保留了左VWFA或右VWFA补偿），而那些具有不良单词阅读能力的阅读障碍却没有；真正的单词阅读能力与VWFA中的选择性相关（AIM 1）。其次，这项研究将检验以下假设：由于语音编码的弱点，患有阅读障碍的成年人比典型的读者表现出对左顶皮层语音处理的选择性较少，并且伪戈德阅读能力与顶叶选择性相关（AIM 2）。这些研究将首次成为可能在阅读障碍而不是仅仅激活水平的大脑活动的特异性。如果我们要了解导致阅读障碍的机制，并且重要的是，请指导应采用哪些干预措施，因为当前治疗可能会影响不同的大脑系统，因此这些信息至关重要。推进这一领域可以减少读者受损的数量，并限制阅读障碍的有害教育和职业后果。 公共卫生相关性：发育阅读障碍是阅读障碍的常见（占人群的5-12％），与其他认知能力和提供教育机会有关。一种新的成像方法将通过比较阅读障碍和非阅读障碍的大学生来更好地理解阅读涉及阅读涉及的脑电路的特异性。结果将提高我们对导致阅读障碍的机制的理解，并潜在地指导未来的干预措施，最终减少读者受损的数量，并限制阅读障碍的有害教育和职业后果。

项目成果

Getting a handle on how the brain generates complexity.

了解大脑如何产生复杂性。

• DOI: 10.3109/0954898x.2012.711918
• 发表时间: 2012
• 期刊: Network (Bristol, England)
• 作者: Riesenhuber,Maximilian