阅读障碍儿童单字词加工的工作记忆研究

发布时间：2018-01-03 07:33

本文关键词：阅读障碍儿童单字词加工的工作记忆研究　出处：《湖南师范大学》2013年硕士论文　论文类型：学位论文

【摘要】：目的：通过阅读障碍组和正常对照组儿童对单个汉字的读音、字形的匹配判断,考察阅读障碍儿童工作记忆的言语(语音回路)、视觉子系统(视空模板)的缺陷及其神经机制。方法：(1)采用精神障碍诊断和统计手册第四版(DSM-IV-TR)、韦氏儿童智力测验中国修订版第四版(WISC-IV)和小学生多重成就测验(MATs)等量表,结合教师的评定和学生成绩,从600名3-5年级小学生中筛选出21名阅读障碍儿童作为实验组,另选22名正常儿童组成对照组。(2)采用n-back工作记忆范式(取n=2水平),以儿童所熟悉的汉字单字词为实验材料,以完全匹配与不匹配两种刺激模式,对汉字的字音和字形分别进行ERP实验研究。结果：(1)行为数据结果表明,正常对照组儿童字音的正确率明显高于阅读障碍组的(F(1,30)=6.835,p=0.014,η2=0.186)；匹配刺激类型的反应时明显长于不匹配刺激类型的(F(1,30)=48.456,p=0.000,η2=0.602)。在字形反应上,主效应和交互效应均不显著。(2)脑电结果表明,与正常组儿童相比,阅读障碍儿童在字音反应上左枕颞波幅小于右枕颞,早期N2波幅下降、VPP波幅增加、晚期LPP波幅下降；VPP潜伏期明显高于对照组；匹配刺激N2潜伏期明显高于不匹配刺激,对照组无类似显著差异。与正常儿童相比,阅读障碍儿童字形反应早期Nl波幅增加、晚期LPP波幅下降,早成分及晚成分的潜伏期上阅读障碍组与对照组差异不显著。结论：(1)阅读障碍儿童在字音和字形实验上的ERP晚期成分上都表现出在顶中区的激活不足,提示顶中区功能不良可能是工作记忆缺陷的神经机制。(2)与对照组相比,阅读障碍组在字音和字形反应上都表现出早期ERP成分波幅增加,晚期LPP波幅下降的现象,说明在字音与字形的早期识别阶段阅读障碍儿童需要消耗过多的心理资源,进而影响到其后续的工作记忆加工活动效能。(3)阅读障碍儿童言语加工上存在左脑偏侧化,而视觉加工上则表现出全脑性不足,这说明阅读障碍儿童全脑协调能力较正常儿童低下,且字形的加工在早期识别上可能作用更大。
[Abstract]:Objective: to investigate the speech (phonological loop) of working memory of dyslexic children by matching the pronunciation and shape of individual Chinese characters between the dyslexia group and the normal control group. The defect of visual subsystem (visual space template) and its neural mechanism. Methods DSM-IV-TR1 was used in 4th edition of Diagnostic and Statistical Manual of Mental Disorder (DSM-IV-TR1). Wechsler Children's Intelligence Test (WISC-IV) and multiple Achievement Test for pupils (WISC-IV), Chinese version 4th, combined with teachers' assessment and students' scores. Twenty-one children with dyslexia were selected from 600 pupils of grade 3-5 as experimental group. Another 22 normal children were selected as control group (n-back working memory paradigm). The sound and shape of Chinese characters were studied by ERP experiment in two stimulus modes: perfect match and mismatch. Results the results of behavior data showed that the correct rate of Chinese characters in normal children was significantly higher than that in dyslexia group (6.835 / 0.014). 畏 _ 2 ~ (0.186); The response time of matching stimulus type was significantly longer than that of non-matching stimulus type, 48.456p0. 000, 畏 2 + 0. 602 in the zigzag response. The results of EEG showed that the amplitude of left occipito-temporal wave was lower in reading impaired children than that in right occipito-temporal response, and the amplitude of N _ 2 wave in early stage was lower than that in normal group. The amplitude of VPP increased and the amplitude of LPP decreased in late stage. The latency of VPP was significantly higher than that of control group. The N _ 2 latency of matched stimulation was significantly higher than that of mismatched stimulation, but there was no similar significant difference in the control group. Compared with the normal children, the N _ l amplitude in the early stage of glyph reaction in children with dyslexia increased, but the amplitude of LPP decreased in the late stage. There was no significant difference in latency of early and late components between dyslexia group and control group. Conclusion (1) the late components of ERP in dyslexia children showed insufficient activation in the central parietal region in both phonetic and glyph tests. The results suggest that the central parietal dysfunction may be the neural mechanism of working memory impairment.) compared with the control group, the dyslexia group showed an early increase in the amplitude of ERP components in both phonetic and glyphic responses. The decline of LPP amplitude in the late stage indicates that children with dyslexia need to consume too much psychological resources in the early recognition of phonetic and glyph. Thus affecting its subsequent working memory processing efficiency. 3) Children with dyslexia have left brain lateralization in speech processing, while the visual processing shows a lack of the whole brain. This indicates that the whole brain coordination ability of children with dyslexia is lower than that of normal children, and the processing of glyph may play a more important role in early recognition.
【学位授予单位】：湖南师范大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：G625.5;G442

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