Directly testing the magnocellular theory of dyslexia

直接测试阅读障碍的大细胞理论

• 批准号: 9792265
• 负责人: KEITH ALLAN SCHNEIDER
• 金额: $ 38.31万
• 依托单位: UNIVERSITY OF DELAWARE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-30 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9792265
• 关键词: Affect; Anatomy; Attention; Attentional deficit; Attenuated; Auditory; Autopsy; Behavioral; Brain; Cell Nucleus; Data; Disease; Disinhibition; Dyslexia; Exhibits; Experimental Designs; Frequencies; Functional Magnetic Resonance Imaging; Functional disorder; Future; Geniculate body structure; Goals; Human; Image; Impairment; Individual; Lateral Geniculate Body; Legitimacy; Location; Maps; Measurement; Measures; Medial; Midbrain structure; Modeling; Neurons; Outcome; Population; Property; Protons; Publishing; Reading; Reporting; Research Personnel; Resolution; Resources; Sensory; Series; Stimulus; Stream; Structure; System; Techniques; Testing; Thalamic Nuclei; Thalamic structure; Visual; Visual system structure; Visuospatial; attentional control; attentional modulation; density; experimental study; magnocellular; parvocellular; receptive field; response; retinotopic; sensory system; superior colliculus Corpora quadrigemina; theories; treatment strategy

Abstract The goal of this project is to directly test the magnocellular theory of dyslexia (MTD) by measuring the function of the magnocellular (M) system in the thalamus. Dyslexia is a reading specific disorder that affects 5% of the population. The MTD is a prominent but controversial theory that proposes that the behavioral deficits in dyslexia are a consequence of the dysfunction of the M system in the brain, which is specialized for the processing of transient information. Because the M system cannot be isolated behaviorally, and because the M stream becomes intermixed with other streams in the cortex, the MTD has never been properly tested. However, the M system remains spatially segregated in the sensory nuclei in the thalamus. Therefore, the MTD will be tested using high-resolution functional magnetic resonance imaging (fMRI) to measure thalamic function in each of three independent aims: 1. Is temporal processing in the lateral geniculate nucleus (LGN) and thalamic reticular nucleus (TRN) normal in dyslexia? 2. Does the M portion of the medial geniculate nucleus (MGN) function normally in dyslexia? 3. Does attention modulate the LGN, MGN and TRN normally in dyslexia? In Aims 1 and 2, measuring the M systems in the MGN and LGN will determine whether M dysfunction, if present, is a general property of the brain in dyslexia, or whether it is confined to a single sensory system. One of the primary functions of the thalamus is to control attention, and Aim 3 will test whether the attentional deficits that have been reported in dyslexia are specific to the M system. Together these experiments provide a comprehensive test of MTD and will serve to resolve its validity. which will have an important impact on the understanding and treatment of dyslexia. This project will use a combination of simple stimuli and experimental designs with experimental and analytical techniques that have been proven in our lab to be able to reliably examine the small and noisy subcortical nuclei, including: high-resolution fMRI; massively averaged high- resolution proton-density weighted images that can resolve the anatomical boundaries of the subcortical nuclei; population receptive field modeling of temporal responses and retinotopic and tonotopic organization; and data-driven filtering and clustering. The results of this project will provide an unprecedented direct test that will ultimately settle the legitimacy of the MTD. This will help guide the allocation of future resources in understanding and treating dyslexia.

抽象的 该项目的目的是直接通过测量阅读障碍（MTD）的巨细胞理论来测量 丘脑中大细胞（M）系统的功能。阅读障碍是一种阅读障碍 影响5％的人口。 MTD是一种突出但有争议的理论，提出 阅读障碍的行为缺陷是大脑中M系统功能障碍的结果， 专门用于处理瞬态信息。因为M系统无法隔离 行为上，并且由于M流与皮质中的其他流相互混合，所以MTD 从未经过适当的测试。但是，M系统在感觉中保持空间隔离 丘脑中的核。因此，将使用高分辨率功能磁性测试MTD 共振成像（fMRI）在三个独立目标中测量丘脑功能： 1。是横向元音核（LGN）和丘脑网状核中的时间加工 （TRN）阅读障碍中正常？ 2。内侧基因核（MGN）的M部分是否正常在阅读障碍中起作用？ 3。注意是否会在阅读障碍中调节LGN，MGN和TRN？ 在AIMS 1和2中，测量MGN和LGN中的M系统将确定M是否是否 功能障碍（如果存在）是大脑在阅读障碍中的一般特性，或者是否仅限于单个 感官系统。丘脑的主要功能之一是控制注意力，AIM 3将测试 阅读障碍中报告的注意力缺陷是否特定于M系统。 这些实验共同提供了MTD的全面测试，并将有助于解决其有效性。 这将对阅读障碍的理解和治疗产生重要影响。 该项目将结合简单刺激和实验设计与 在我们的实验室中已证明的实验和分析技术能够可靠地检查 小型和嘈杂的皮层核，包括：高分辨率fMRI；大量平均高 - 分辨率质子密度加权图像可以解决下皮质的解剖边界 核；时间响应以及视网膜和吨位的人群接受场模型 组织;以及数据驱动的过滤和聚类。 该项目的结果将提供前所未有的直接测试，最终将解决 MTD的合法性。这将有助于指导未来资源在理解和 治疗阅读障碍。