用汉字书写的文本，会因词切分的不同而产生意义上很大差异。如"武汉市长江大桥"可切分为"武汉 市长 江大桥"和"武汉市 长江 大桥"。因此，汉语阅读的首要任务是读者正确进行词切分。用空格作为词切分线索研究发现，在汉语文本中加入空格能促进外国留学生、儿童和成人的阅读。熟练的汉语读者能利用成词概率、词素位置概率和词素熟悉性等语言线索进行词切分。在我国阅读障碍儿童占学龄儿童总数的5-10%，他们在阅读过程中存在词切分缺陷但很少被临床所关注。本项目首先用眼动记录技术查明阅读障碍儿童利用哪种语言线索存在缺陷；其次将眼动记录技术与功能近红外光学成像技术结合，探讨阅读障碍儿童存在缺陷的认知及脑机制；最后用功能核磁共振技术检测词切分作为诊断阅读障碍儿童指标的有效性，同时通过词切分的强化训练，考察阅读障碍儿童在训练前后阅读能力改善的情况以及相应脑区激活的变化。

It is very uncontroversial that in alphabetic writing systems like English, the spaces between words facilitate reading. Unlike English, Chinese do not include spaces between words, the text is formed by strings of equally spaced symbols called characters. Chinese readers do not know clearly about which characters do actually comprise a word. However, in order to recognize a word, the primary task for a Chinese reader is to segment words correctly during reading. Some studies have showed that word spaces facilitated Chinese reading for children, adults and second language learners when reading Chinese as their second language. During normal Chinese reading, even though there is no word space, skilled readers can use high-level linguistic segmentation cues, such as the probability of being a single character word, character's positional probability and the familiarity of constituents. However, about 5-10% of the school children in Chinese are dyslexic children, who have deficits of word segmentation but have been neglected in the domain of clinic. The present project will firstly check in the level of dyslexic childre's word segmentation deficit using eye tracking. Secondly, we will combine eye tracking and near infrared reflectance spectroscopy (fNIRS) to investigate the behavioral and brain mechanisms of dyslexic children's word segmentations. Finally, we will examine the validity of word segmentation using as an indicator to detect dyslexic children by functional magnetic resonance imaging (fMRI). Meanwhile, we will explore how the reading proficiency of dyslexic children will be improved after trainning.