视觉及听觉刺激诱发语言通路的fMRI初步探讨

Visual vs auditory Chinese single-character word clues:an fMRI study

目的利用功能核磁共振成像(fMRI)探讨视觉刺激和听觉刺激诱发的大脑思维活动,大脑激活区域的差异。方法采用血氧水平依赖法(BOLD)组块设计,考查6例以汉语为母语的健康中国志愿者,接受中文单音节字的视觉和听觉任务刺激,通过组词来诱发思维活动时,相关脑区激活特点,并分析其差异。结果视觉任务主要激活了双侧额上回、中央前回及枕叶,左侧额中回、顶上小叶,右侧颞上回;听觉任务主要激活了双侧颞上回、中央前回及枕叶,左侧顶上小叶。听觉任务见到小脑和基底节区的激活。两种任务都伴随海马激活。结论组词过程激活的脑区交叉多。颞叶和枕叶在2种任务都有激活。

Objective To examine by fMRI whether there is shared neural circus at the level of word-pair forming and reacting to visual and auditory Chinese single character clues. Methods The brain activation was examined while participants read or listened to Chinese high-imagery single-character word clue, like Cao （straw, in English） , and formed word-pairs, like Caoxie, Caomao, Caosheng,et al （straw sandals, straw hat, straw rope, in English） , as many as possible, with the word clue limited as the first character. The word clues were confined to nouns, so as the word-pairs formed. Results Both the auditory and visual presentation experiments indicated the activation of superior frontal gyrus, superior parietal lobule, superior temporal gyrus, inferior frontal gyrus, and occipital lobe. There was more activation of hippocampus in the auditory experiment, which was associated with the information storage. Activation in the left superior temporal areas was correlated with semantic retrieval and processing. In most participants who visualized the surface structure of certain Chinese character they heard, the significant activation in occipital lobe, for the auditory experiment, connected with the speech process. Especially, the activation of cerebellum and basal ganglion in the auditory experiment, suggested that the unique spatial surface structure of Chinese characters might play a role. Conclusion The activated areas are largely overlapping regardless of the input modality. Neither the occipital lobe was visionspecific nor the temporal gyrus was auditory-specific.