Maastricht Brain Imaging Center, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, Maastricht, MD 6200, Netherlands.
Maastricht Brain Imaging Center, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, Maastricht, MD 6200, Netherlands.
Neuroimage. 2022 Jul 1;254:119142. doi: 10.1016/j.neuroimage.2022.119142. Epub 2022 Mar 25.
Developmental dyslexia is often accompanied by altered phonological processing of speech. Underlying neural changes have typically been characterized in terms of stimulus- and/or task-related responses within individual brain regions or their functional connectivity. Less is known about potential changes in the more global functional organization of brain networks. Here we recorded electroencephalography (EEG) in typical and dyslexic readers while they listened to (a) a random sequence of syllables and (b) a series of tri-syllabic real words. The network topology of the phase synchronization of evoked cortical oscillations was investigated in four frequency bands (delta, theta, alpha and beta) using minimum spanning tree graphs. We found that, compared to syllable tracking, word tracking triggered a shift toward a more integrated network topology in the theta band in both groups. Importantly, this change was significantly stronger in the dyslexic readers, who also showed increased reliance on a right frontal cluster of electrodes for word tracking. The current findings point towards an altered effect of word-level processing on the functional brain network organization that may be associated with less efficient phonological and reading skills in dyslexia.
发展性阅读障碍常伴有语音的语音处理改变。基础的神经变化通常是根据个体大脑区域的刺激和/或任务相关反应及其功能连接来描述的。对于大脑网络更全局的功能组织的潜在变化知之甚少。在这里，我们在典型阅读者和阅读障碍者听（a）随机音节序列和（b）一系列三音节真实单词时记录了脑电图（EEG）。我们使用最小生成树图在四个频带（δ、θ、α和β）中研究了诱发皮质振荡的相位同步的网络拓扑。与音节跟踪相比，我们发现，在两组中，单词跟踪都会引发θ频带中更集成的网络拓扑的转变。重要的是，阅读障碍者的这种变化更为明显，他们在单词跟踪时也更加依赖于右额电极集群。目前的研究结果表明，单词处理对功能大脑网络组织的影响可能与阅读障碍者中语音和阅读技能的效率较低有关。
