Biological abnormality of impaired reading is constrained by culture
Biological abnormality of impaired reading is constrained by culture
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DOI：
10.1038/nature02865
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发表时间：
2004-09-02
期刊：
影响因子：
64.8
通讯作者：
Tan, LH
中科院分区：
文献类型：
--
作者：
Siok, WT;Perfetti, CA;Tan, LH
发展性阅读障碍的特点是在智力和教育正常的人群中出现严重的阅读问题（1-3）。字母阅读障碍与左颞顶叶脑区功能障碍有关（2-5）。这些区域进行音位分析并将书面符号转换为语音的音位单位（字素-音素转换）；介导阅读习得的两个中心认知过程（6-7）。此外，有人认为，与文化多样性相反，不同语言的阅读障碍具有普遍的生物起源（1,8）。在这里，我们通过对阅读障碍的中国儿童和相关对照组的功能性磁共振成像显示，左额叶中回的功能性破坏与汉语阅读障碍有关（汉语是一种符号而非字母书写系统）。汉语的阅读障碍主要表现在两个方面：一是字形（正字法）到音节的转换缺陷，二是正字法到语义的映射缺陷。这两个过程都是由左额中回介导的，额中回是流畅中文阅读的中心（9-11），协调和整合书面文字在言语和空间工作记忆中的各种信息。这一发现为阅读障碍的基本病理生理学提供了一种见解，表明阅读障碍的生物学异常依赖于文化，而不是具有普遍的起源。
Developmental dyslexia is characterized by a severe reading problem in people who have normal intelligence and schooling(1-3). Impaired reading of alphabetic scripts is associated with dysfunction of left temporoparietal brain regions(2-5). These regions perform phonemic analysis and conversion of written symbols to phonological units of speech (grapheme-to-phoneme conversion); two central cognitive processes that mediate reading acquisition(6-7). Furthermore, it has been assumed that, in contrast to cultural diversities, dyslexia in different languages has a universal biological origin(1,8). Here we show using functional magnetic resonance imaging with reading-impaired Chinese children and associated controls, that functional disruption of the left middle frontal gyrus is associated with impaired reading of the Chinese language ( a logographic rather than alphabetic writing system). Reading impairment in Chinese is manifested by two deficits: one relating to the conversion of graphic form ( orthography) to syllable, and the other concerning orthography-to-semantics mapping. Both of these processes are critically mediated by the left middle frontal gyrus, which functions as a centre for fluent Chinese reading(9-11) that coordinates and integrates various information about written characters in verbal and spatial working memory. This finding provides an insight into the fundamental pathophysiology of dyslexia by suggesting that rather than having a universal origin, the biological abnormality of impaired reading is dependent on culture.