【作者】 周晓；

【导师】 罗本燕；

【作者基本信息】 浙江大学 ， 神经病学， 2011， 博士

【摘要】 语言习得的大脑生理基础以及对应基因基础为最近研究热点。本研究首先建立一个网上科研辅助系统,然后应用了一系列神经心理学、行为遗传学及影像学的方法,试图回答以下问题：五岁儿童是否能习得汉语被动句?其习得过程是否具有基因基础?是否和特别的大脑半球相关?以五岁左右为分界点,早晚期习得的词语是否联系于不同的大脑机制?第一部分研究通过句图匹配范式来测试151个儿童(含54对双胞胎),以探讨五岁左右汉语被动句习得情况及其基因基础。结果显示：5岁时儿童理解非动作性长短被动句的正确率为随机水平,但动作性长短被动句的正确率高于随机水平5岁以后,小孩理解各型被动句的正确率均快速增加。仅遗传因素显著影响非动作性长短被动句的正确率。遗传因素和环境因素对动作性长被动句的影响几乎是一样的,而环境因素对动作性短被动句的影响要比遗传因素的影响大很多。由此可知,类似英语被动句,汉语被动句(非动作性被动句)在五岁习得。遗传因素可能引导儿童习得非动作性被动句式,儿童在早期很可能应用形容词策略来理解动作性被动句。第二部分研究通过分视野速视实验来测试一例罕见的右侧大脑病灶导致纯左视野失读病例,一方面为了探索中央凹视觉词形的投射通路,一方面为第三部分研究的开展做理论和技术的准备。本实验的弥散张量成像数据显示右侧联结枕颞叶的胼胝体压部纤维被大量破坏,几乎没有纤维残留。实验结果显示,患者中央凹左部汉字及汉字部件阅读障碍,而对照组无阅读困难。本实验结果支持中央凹视野交叉投射到对侧大脑半球的假说。第三部分研究通过分视野速视的方法来测试五十六个健康成人,以探索不同型被动句和左右脑之间联系。实验结果提示：图句判断试验中动作性被动句具有右大脑半球优势,而非动作性被动句具有左大脑半球优势；而句图判断试验中结果正好相反。结合以往其他研究：被试在句图判断任务中更多地是运用了相应的视觉空间能力,而句图判断试验的功能磁共振实验中显示动作性被动句比主动句引起较强左侧额叶激活。由此得出假设,非动作性被动句的句法相关工作记忆很可能依赖于左脑,而视觉图像相关的工作记忆很可能依赖于右脑；动作性被动句的句法相关工作记忆很可能依赖于右脑,而视觉图像相关的工作记忆很可能依赖于左脑。第四部分借助已有图片命名常模及功能磁共振技术来研究一名纯命名障碍的病例,以探讨以五岁左右为分界限区域的早晚期习得词汇与大脑结构之间的联系。结果显示：在康复早期,词汇习得年龄和熟悉度同时起着重要作用,在康复晚期,仅熟悉度效应显著存在。康复早期能命名时患者右侧BA37区激活强度较大。由此得出假设：命名实验结果可能和早晚期明显不一样的病理过程有关。图片很可能是通过左右BA18收集和初步处理,再经由左侧BA37/19直接传递给左侧角回,或从右侧BA1 8区经过右侧BA37/19区处理后,再通过胼胝体传到左侧BA37/19区。5岁前习得的词也可以不经过左侧BA37/19区直接通过胼胝体提交给左侧角回处理,但是该通路在正常人脑中被抑制。更多还原

【Abstract】 The cerebral structures and genes in language acquisition, which attract many researchers, are still unclear. We first built an online computer-assistant research system and then applied some methodologies of neuropsychology, behavioral genetics and neuroimaging to answer these questions:is Mandarin passives acquired after five? Does it have any cerebral or genetic basis? Does words age of acquisition associate with different cerebral areas or pathways?In the first part, we studied on 151 children (including 54 pairs of twins) to acquire evidence for genetic basis in passives. The results showed that children acquired non-actional passives after 5 years old. Only genetic factors affected accuracy in non-actional passives. Compared to heritability, environment effect was higher in actional short passives but was equal in actional long passives. These data suggests that acquiring of non-acitonal passives might be guided by genetic factors, while comprehension of actional passives might associate with adjective strategy.In the second part, we tried to comprehend the projection pathway of foveal visual words in a rare case of pure hemialexia, in order to provide theoretic and technological basis. Diffuse tensor imaging shown that few fibers remained in the right ventroposterior part of the splenium. The correct naming scores of the characters presented completely in the right fovea were significantly higher than the correct naming scores of other stimuli. These phenomena support the split fovea theory and can not be easily explained by the bilateral projection theory. In the third part, we tried to present sentences in different visual field for 200 ms to explore the relationship between hemispheres and different types of passives in 56 adults. The results shown that in the picture-sentence verification task, actional passives related with right hemisphere, while non-actional passives related with left hemisphere. The trends were totally revealed in the sentence-picture verification task. Based on previous research, these subjects might rely on visual-spatial working memory in the first task, thus the syntactic working memory of non-actional passives might rely on left hemisphere but its visual working memory associated with right hemisphere, whereas these reversions in working memory of actional passives were revealed by our data. We did not find any relationship between actives and cerebral hemispheres.In the final part, we tried to explore cerebral basis of words age of acquisition (words acquired before or after 5 years old).The results shown that AOA was not significant in the total recovery although it played an important role in the early recovery, while familiarity was always significant. Right BA 37 was more active when the patient retrieved the word and was able to name. Our hypothesis was that pictures’ information was collected by bilateral BA 18 and then sent to angular gyrus through left BA 37/19. Right BA 18 usually sent the information to right BA 37/19 and then to left BA 37/19 through corpus callosum. Low AOA words might be sent directly to angular gyrus to angular gyrus, however, the pathway was absent in health subjects.更多还原