N300 indexes deficient integration of orthographic and phonological representations in children with dyslexia
N300 indexes deficient integration of orthographic and phonological representations in children with dyslexia
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DOI：
10.1016/j.neuropsychologia.2012.01.001
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发表时间：
2012-04-01
期刊：
影响因子：
2.6
通讯作者：
Schulte-Koerne, Gerd
中科院分区：
文献类型：
--
作者：
Hasko, Sandra;Bruder, Jennifer;Schulte-Koerne, Gerd
在透明拼字法中，例如德语，患有发育性阅读障碍（DD）的儿童的主要特征是阅读流畅性缺陷。阅读流畅性的缺陷可能可以追溯到拼写和语音表征的缺乏整合。为了解决这个问题，本研究使用脑电图来研究 N300，这是一个与拼字法和语音表征的整合相关的 ERP 组件。 20 名没有 DD 的儿童和 18 名患有 DD 的儿童执行了语音 (P)-拼写 (0) 匹配任务（P-O 条件），该任务利用了拼写和语音表征的整合。应用的控制任务不需要整合拼字法和语音表示，仅包含拼字法信息（O-O 条件）。 O-O 条件揭示了在额颞电极上具有双边活动的组之间相似的 N300 分布。然而，在 P-O 条件下，N300 区分了 2 组儿童。对照组显示左侧额颞叶电极的活动更大，而 DD 儿童组的 N300 分布在双侧，表明字法和语音表征的整合不足。这些发现可能与阅读流畅度不足有关，因为还观察到，更好的阅读流畅度与左半球较高 (r = -.36) 和较早达到峰值 (r = -.33) 的 N300 振幅以及右半球减弱的 N300 振幅 (r = .45) 相关。标准化低分辨率电磁断层扫描分析 (sLORETA) 显示，与没有 DD 的儿童相比，患有 DD 的儿童更多地依赖右颞顶叶脑区域。此外，为了排除早期缺陷过程可能影响 N300 中发现的组差异，我们分析了 N170 的组差异。我们没有发现没有 DD 的儿童和患有 DD 的儿童之间存在显着差异。总之，结果表明，如 N300 所索引的，阅读障碍中的拼写和语音表征的整合不足，并进一步强调了这项活动与流利阅读的相关性。 (C) 2012 Elsevier Ltd. 保留所有权利。
In transparent orthographies, like German, children with developmental dyslexia (DD) are mainly characterized by a reading fluency deficit. The reading fluency deficit might be traced back to a scarce integration of orthographic and phonological representations. In order to address this question, the present study used EEG to investigate the N300, an ERP component which has been associated with the integration of orthographic and phonological representations. Twenty children without DD and 18 children with DD performed a phonological (P)-orthographic (0) matching task (P-O condition), which tapped the integration of orthographic and phonological representations. A control task was applied which did not require the integration of orthographic and phonological representations and consisted only of orthographic information (O-O condition). The O-O condition revealed a similar N300 distribution between groups with a bilateral activity over fronto-temporal electrodes. However, in the P-O condition N300 differentiated the 2 groups of children. The control group revealed greater activity over left fronto-temporal electrodes, whereas the N300 was distributed bilaterally in the group of children with DD suggesting deficient integration of orthographic and phonological representations. These findings might be related to the reading fluency deficit as it was also observed that better reading fluency was correlated with higher (r = -.36) and earlier peaking (r = -.33) N300 amplitudes in the left hemisphere and attenuated N300 amplitudes (r = .45) in the right hemisphere. Standardized low-resolution electromagnetic tomography analysis (sLORETA) revealed that children with DD rely more on right temporo-parietal brain areas compared to children without DD. Furthermore, in order to rule out that earlier deficient processes might influence the group differences found in the N300, we analyzed the N170 for group differences. We did not find significant differences between children without DD and children with DD. In conclusion the results suggest deficient integration of orthographic and phonological representations in dyslexia, as indexed by the N300, and further highlight how this activity is relevant for fluent reading. (C) 2012 Elsevier Ltd. All rights reserved.