PNAS：不同语言失读症患者脑构造不同
一项最新研究在比较了英语和中文的阅读者之后提出，失读症可能源于不同语言的阅读者的不同神经条件。相关论文4月7日在线发表于美国《国家科学院院刊》（PNAS）上。
之前有神经成像研究表明，相较于文字语言的阅读者来说，不能阅读像英语这样字母语言的失读症患者的大脑灰质体积更小，后脑区的阅读活动能力也较弱。
Li-Hai Tan所在的研究小组对患有失读症的中国儿童进行了研究，以了解这种异常情况是否具有全球性。研究人员采用了两种成像技术进行分析，即评估大脑体积的基于体素的MRI形态分析法和功能性磁共振成像。他们发现，不能阅读中文这种词符型、基于文字的语言的失读症患者的受损脑区和字母语言的失读症患者完全不同。具体来说，中文失读症儿童的脑部左中前回在结构上和功能上都有缺陷，这部分脑区在工作记忆的认知资源协调中具有重要作用。然而，这些儿童的后部脑系统完全正常。研究人员表示，这项研究有助医生们制定更具针对性的治疗方案，帮助全球大约17%的受到失读症困扰的学童。（来源：EurekAlert!中文版）
生物谷推荐原始出处：
（PNAS），doi：10.1073/pnas.0801750105，Wai Ting Siok，Li Hai Tan
A structural–functional basis for dyslexia in the cortex of Chinese readers
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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.
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