Xia Zhichao, Yang Ting, Cui Xin, Hoeft Fumiko, Liu Hong, Zhang Xianglin, Liu Xiangping, Shu Hua
State Key Laboratory of Cognitive Neuroscience and Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China.
School of Systems Science, Beijing Normal University, Beijing, China.
Front Psychol. 2022 Jan 25;12:748644. doi: 10.3389/fpsyg.2021.748644. eCollection 2021.
Conquering print-sound mappings (e.g., grapheme-phoneme correspondence rules) is vital for developing fluent reading skills. In neuroimaging research, this ability can be indexed by activation differences between audiovisual congruent against incongruent conditions in brain areas such as the left superior temporal cortex. In line with it, individuals with dyslexia have difficulty in tasks requiring print-sound processing, accompanied by a reduced neural integration. However, existing evidence is almost restricted to alphabetic languages. Whether and how multisensory processing of print and sound is impaired in Chinese dyslexia remains underexplored. In this study, we applied a passive audiovisual integration paradigm with functional magnetic resonance imaging to investigate the possible dysfunctions in processing character-sound (opaque; semantics can be automatically accessed) and pinyin-sound associations (transparent; no particular meaning can be confirmed) in Chinese dyslexic children. Unexpectedly, the dyslexic group did not show reduced neural integration compared with typically developing readers in either character or pinyin experiment. However, the results revealed atypical correlations between neural integration and different reading abilities in dyslexia. Specifically, while the neural integration in the left inferior frontal cortex in processing character-sound pairs correlated with silent reading comprehension in both children with and without dyslexia, it was associated with morphological awareness (semantic-related) in controls but with rapid naming (phonological-related) in dyslexics. This result indicates Chinese dyslexic children may not use the same grapho-semantic processing strategy as their typical peers do. As for pinyin-sound processing, while a stronger neural integration in the direction of "congruent > incongruent" in the left occipito-temporal cortex and bilateral superior temporal cortices was associated with better oral reading fluency in the control group, an opposite pattern was found in dyslexia. This finding may reflect dyslexia's dysfunctional recruitment of the regions in grapho-phonological processing, which further impedes character learning.
掌握印刷体与语音的映射关系（例如，字素-音素对应规则）对于培养流畅的阅读技能至关重要。在神经影像学研究中，这种能力可以通过左颞上叶皮质等脑区中视听一致与不一致条件之间的激活差异来衡量。与此一致的是，患有阅读障碍的个体在需要印刷体-语音处理的任务中存在困难，同时伴有神经整合能力下降。然而，现有证据几乎仅限于字母语言。汉语阅读障碍中印刷体和语音的多感官处理是否以及如何受损仍未得到充分研究。在本研究中，我们应用功能磁共振成像的被动视听整合范式，来探究汉语阅读障碍儿童在处理汉字-语音（不透明；语义可自动获取）和拼音-语音关联（透明；无特定含义可确定）时可能存在的功能障碍。出乎意料的是，在汉字或拼音实验中，与发育正常的读者相比，阅读障碍组并未表现出神经整合能力下降。然而，结果揭示了阅读障碍中神经整合与不同阅读能力之间的非典型相关性。具体而言，虽然处理汉字-语音对时左额下回皮质的神经整合与有和没有阅读障碍的儿童的默读理解能力都相关，但在对照组中它与形态意识（语义相关）相关，而在阅读障碍者中与快速命名（语音相关）相关。这一结果表明，汉语阅读障碍儿童可能没有使用与正常同龄人相同的字形-语义处理策略。至于拼音-语音处理，虽然在左枕颞叶皮质和双侧颞上叶皮质中“一致>不一致”方向上更强的神经整合与对照组更好的口语阅读流畅性相关，但在阅读障碍中发现了相反的模式。这一发现可能反映了阅读障碍在字形-语音处理区域的功能失调招募，这进一步阻碍了汉字学习。
