【作者】 何立岩；

【导师】 伍建林；

【作者基本信息】 大连医科大学 ， 影像医学与核医学， 2003， 硕士

【摘要】 目的：使用功能磁共振成像(fMRI)对参与汉字、数字及英文处理的大脑皮层区域进行确认，比较汉字与数字、汉字与英文在大脑的加工处理过程有何异同，并对fMRI在大脑功能区定位方面的应用价值及可靠性进行探讨。 材料与方法：包括两组实验，实验1：对12例右利手、母语为汉语且裸眼视力正常的健康受试者分别进行了汉字、数字的看和默读实验。实验2：同样选取12例右利手、母语为汉语且裸眼视力正常的健康受试者，英语程度为大学英语四级以上，实验内容包括中英文的真字、假字和非字。MRI检查在GE Signa 1.5Techospeed MR/i机器上完成，采集脑部的fMRI数据，结果处理应用SPM99软件，通过相关分析进行统计学处理并得到脑功能活动的图像。 结果：对数字和汉字的认知加工实验表明，汉字的处理过程中有额中回，额下回(BA9,BA46)的明显激活，而数字刺激时其激活体积及激活显著性有所下降，统计学处理有明显差异(p＜0.01)；看和默读的过程相比较，发现在进行默读任务时参与的脑区明显增多，也就说能更多地激活脑内相关功能区，如额叶、基底节部分核团、扣带回等。中英文字形辨认实验结果表明，汉语真字和英语真字在左侧大脑半球的激活体积明显大于右侧半球，这说明字词加工的优势半球为左侧大脑半球，汉语真字和英语真字在枕叶，中央前回，额下回(BA18,BA6,BA9)都引起了激活(p＜0.01)；同时显示除了枕叶以外，汉语真字在额叶、颞叶、顶叶的激活体积和激活显著性要明显小于英语真字在这些部位所产生的激活体积和激活显著性，表明国人对英文字词的识别需要更多的脑区处理来实现。 结论：进行汉字认知时双侧额中回，额下回(BA9,BA46)明显激活，而数字加工时额叶激活区相对减少，这说明额叶在对汉字字形和字意的处理中起到重要的作用，由本实验结果推测双侧额叶尤其是额中回可能为语言工作记忆及执行控制单元中心。汉语真字和英语真字识别时产生的激活脑区基本一致，但英语真字的激活更明显一些，而且都反映了语言加工的优势半球均为左半球，同时，两者在额叶、颗叶、顶叶、枕叶上的激活体积和激活显著性上有很高的相关性，这支持了脑认知加工网络化的结论。本实验结果说明伽皿1可以对语言处理的有关大脑皮层区域进行定位，具有广阔的发展前景。更多还原

【Abstract】 Purposes:To identify the cortical areas engaged during Chinese word,number and English word processing with functional magnetic resonance imaging(fMRI),To find the difference between different groups(including Chinese word and number,Chinese word and English word) and to examine the application values and reliability of fMRI for localization of functional areas in the human brain.Materials and Methods:Including two different experiments,Test1:twelve young,right-handed,native Chinese speakers participated this study,They were asked to perform four types tasks,in which they were read Chinese word,read number,look Chinese word,look number.Test2:fMRI data were collected on twelve young,right-handed,native Chinese speakers during performance of true-word,false-word and non-word in Chinese and English.MRI examination were performed on GE Signa 1.5T echospeed MR/i,fMRI raw data were dealed with SPM software, A cross correlation analysis were used to statistically generate the activation map.Results:Chinese word and number cognization test showed significant activation in BA9,BA46,While activation volume and significance decreased in number stimulation,Significant difference were found in statistic results(p<0.01).Compared with look,more brain areas participated in read task,for example frontal lobe, basal ganglia and cingulus. Chinese and English grapheme identification test showed that activation volume in left hemisphere of Chinese and English true-word were larger than that of right hemisphere,This demonstrated that the left hemisphere was the dominant hemisphere.activation were seen in BA18,BA6,BA9 when Chinese and English true-words were given ( p<0.01 ) .The activation volume and significance in frontal lobe,temporal lobe,parietal lobe of Chinese true-word were significantly smaller than that of English true-word except for occipital lobe.This demonstrated that the recognition of English words needed more attention .Conclusions:Bilateral frontal middle gyrus and frontal inferior gyrus were significantly activated in Chinese word cognization while the frontal activation areas relatively decreased in number procession,the findings suggest that the frontal lobe plays important role in procession of Chinese grapheme and meanings. We presumed that bilateral frontal lobe especially the frontal middle gyrus possibly were the control unit centre of language procession. The activation areas of Chinese true-word were consistent with that of English true-word,however,the latter were more evident.Both reflect that the dominant hemisphere of language procession is the left hemisphere. And their activation volume and significance of frontal lobe,temporal lobe,parietal lobe,occipital lobe shows high correlation.This support the theory of brain cognization network..fMRI is feasible for localizing cortical areas critical for language processing in the human brain and have a wide foreground.更多还原