一項最新研究在比較了英語和中文的閱讀者之后提出，失讀癥可能源于不同語言的閱讀者的不同神經(jīng)條件,。相關(guān)論文4月7日在線發(fā)表于美國《國家科學(xué)院院刊》（PNAS）上,。
之前有神經(jīng)成像研究表明,，相較于文字語言的閱讀者來說，不能閱讀像英語這樣字母語言的失讀癥患者的大腦灰質(zhì)體積更小,，后腦區(qū)的閱讀活動能力也較弱,。
Li-Hai Tan所在的研究小組對患有失讀癥的中國兒童進行了研究,，以了解這種異常情況是否具有全球性。研究人員采用了兩種成像技術(shù)進行分析,，即評估大腦體積的基于體素的MRI形態(tài)分析法和功能性磁共振成像,。他們發(fā)現(xiàn)，不能閱讀中文這種詞符型,、基于文字的語言的失讀癥患者的受損腦區(qū)和字母語言的失讀癥患者完全不同,。具體來說，中文失讀癥兒童的腦部左中前回在結(jié)構(gòu)上和功能上都有缺陷,，這部分腦區(qū)在工作記憶的認知資源協(xié)調(diào)中具有重要作用,。然而，這些兒童的后部腦系統(tǒng)完全正常,。研究人員表示,，這項研究有助醫(yī)生們制定更具針對性的治療方案，幫助全球大約17%的受到失讀癥困擾的學(xué)童,。（來源：EurekAlert!中文版）
生物谷推薦原始出處：
（PNAS）,，doi：10.1073/pnas.0801750105，Wai Ting Siok,，Li Hai Tan
A structural–functional basis for dyslexia in the cortex of Chinese readers
Wai Ting Siok,, Zhendong Niu, Zhen Jin¶, Charles A. Perfetti||, and Li Hai Tan,,
Department of Linguistics and State Key Laboratory of Brain and Cognitive Sciences, University of Hong Kong, Pokfulam Road, Hong Kong; College of Computer Science and Technology, Beijing Institute of Technology, Beijing 100081, China; ¶Beijing 306 Hospital, Beijing 100101, China; and ||Learning Research and Development Center, University of Pittsburgh, Pittsburgh, PA 15260
Communicated by Robert Desimone, Massachusetts Institute of Technology, Cambridge, MA, February 25, 2008 (received for review January 1, 2008)
Abstract
Developmental dyslexia is a neurobiologically based disorder that affects 5–17% of school children and is characterized by a severe impairment in reading skill acquisition. For readers of alphabetic (e.g., English) languages, recent neuroimaging studies have demonstrated that dyslexia is associated with weak reading-related activity in left temporoparietal and occipitotemporal regions, and this activity difference may reflect reductions in gray matter volume in these areas. Here, we find different structural and functional abnormalities in dyslexic readers of Chinese, a nonalphabetic language. Compared with normally developing controls, children with impaired reading in logographic Chinese exhibited reduced gray matter volume in a left middle frontal gyrus region previously shown to be important for Chinese reading and writing. Using functional MRI to study language-related activation of cortical regions in dyslexics, we found reduced activation in this same left middle frontal gyrus region in Chinese dyslexics versus controls, and there was a significant correlation between gray matter volume and activation in the language task in this same area. By contrast, Chinese dyslexics did not show functional or structural (i.e., volumetric gray matter) differences from normal subjects in the more posterior brain systems that have been shown to be abnormal in alphabetic-language dyslexics. The results suggest that the structural and functional basis for dyslexia varies between alphabetic and nonalphabetic languages.
