中文摘要：

双语者语言加工的神经机制一直是语言认知神经科学研究关注的热点问题之一。前人研究多关注二语加工过程,较少研究母语加工神经网络与二语加工神经网络之间的相互作用;并且前人研究多以成人为被试,研究结果可能会受到发展成熟因素的影响。本研究中,28名汉英儿童双语者进行了两种语言条件下的语音判断任务和字形判断任务,在进行任务的同时进行了磁共振扫描。通过全脑分析、感兴趣区分析和相关分析,结果显示：1）汉语语音、字形加工和英语语音、字形加工激活了类似的脑区网络,但也存在差异。汉语特异脑区（根据Tan等人对汉英跨语言比较的元分析进行定义）右侧枕下回、梭状回以及左侧扣带回在英语语音、字形任务中都显著激活,英语语音任务还额外激活了汉语特异的左脑额中回和中央前回;英语特异脑区（根据Tan等人对汉英进行跨语言比较的元分析进行定义）左脑额内侧、额下回以及梭状回在汉语语音、字形加工中显著激活。2）儿童的英语熟练度越低,左脑扣带回（汉语特异脑区）在汉语语音和汉语字形任务中的激活越强;汉语熟练度越高,左脑额下回（英语特异脑区）在英语字形任务中的激活越强,左脑颞上回（英语特异脑区）在英语语音任务中的激活越弱。两个任务的结果一致说明：汉英双语者母语加工的神经网络与二语加工的神经网络之间存在相互作用,并且受到双语熟练度的调制。

英文摘要：

More than half of the world＇s population are actively learning or speaking a second language. Research in this field thus far has focused primarily on the second language processing alone, but neglect the interaction of the two languages. In addition, majority of the previous studies investigated this issue using bilingual adults. Do bilingual children recruit both native and second language neural networks in second language reading as adults do？ Does second language and native tongue affect one another in bilingual children＇s brain？ To answer these questions, we tested 28 early Chinese-English bilingual children, assigning participants phonological and orthographical processing tasks in both languages while performing brain scans using fMRI. Phonological tasks required participants to determine whether or not displayed Chinese characters were homonyms, while orthographical tasks required these children to judge whether or not the given stimuli were visually similar. In addition to these tasks, participants proficiency in both languages. These tests comprised of a fluency test, and an English dictation test. also undertook four behavioral tests to assess their Chinese character recognition test, a Chinese reading From whole-brain analysis, we found that the two tasks recruited largely similar brain networks across both languages despite of some language differences. Based on an meta-analysis on cross-language comparison, we defined our regions of interest （ROI）. ROI analysis revealed that some Chinese-specific regions （bilateral inferior occipital gyrus, cingulate gyrus, and right fusiform gyrus） were significantly activated in English tasks. Similarly, some English-specific regions （left fusiform gyrus, inferior frontal gyrus, and medial frontal gyrus） were significantly activated in Chinese tasks. Among these regions, Increased activation of the Chinese-specific cingulate gyrus was negatively correlated with English dictation test scores, suggesting that the higher the second language pro