汉字识别中亚词汇语音和语义信息在N170上的神经适应

N170 adaptation effect of the sub-lexical phonological and semantic processing in Chinese character reading

视觉词汇识别的事件相关电位(ERP)研究发现早期的脑电成分N170具有对词汇的敏感性,可能反映了字形、语音和语义加工,目前还没有得到统一的结论。本研究利用汉字形声字声旁表音和形旁表义的独特性,使用神经适应范式深入考察了N170对汉字亚词汇语音和语义信息的敏感性。实验1操纵了连续汉字的声旁和整字读音重复呈现探究其诱发的神经适应性,结果发现了左侧电极的N170对声旁和整字读音重复都产生了神经适应。实验2进一步操纵形旁和整字语义的重复呈现,结果发现左侧N170仅对整字语义相似性具有神经适应性,而右侧N170对形旁和整字语义重复都产生了神经适应。实验结果表明,左侧N170不仅对整字语音和语义信息敏感,还对亚词汇的声旁信息敏感;而右侧N170对整字语义以及亚词汇的形旁信息敏感。

The event-related potential(ERP)studies have revealed a component(N170)near tempo-occipital electrodes was sensitive to visual words.However,its role in word reading is still controversial.A common view is that the N170 engaged in the visual/orthographic processing,whereas some evidence has shown the N170 involved in phonological and semantic processing.By taking advantage of the Chinese writing system's ideographic property,the current study directly examined whether the N170 was sensitive to the phonological and semantic processing in reading Chinese characters.Two ERP experiments were conducted in a neural adaption paradigm by manipulating the repetition of the sub-lexical phonetic/semantic radical.The ERP data were collected while participants performed a phonological judgment task on the 4th character after silently reading the four characters consecutively.The phonological similarity(Experiment 1)and semantic similarity(Experiment 2)were manipulated among the four characters.Experiment 1 examined the neural adaption of the four characters sharing the phonetic radical(e.g.,敏,侮,悔,莓),the character's pronunciation(e.g.,妹,枚,镁,莓),both of them(e.g.,酶,梅,霉,莓),or neither(e.g.,淮,崛,郎,莓)respectively.Experiment 2 examined the neural adaption of the four characters sharing the semantic radical(e.g.,狡,狂,猜,狒),the character's meaning(e.g.,豹,鹿,羚,狒),both of them(e.g.,狮,狼,狐,狒),or neither(e.g.,淮,崛,郎,狒)respectively.In both experiments,the results showed a significant neural adaption at N170 in all of the four conditions.The amplitude of the N170 observed in the 1st character decreased in the 2nd–4th characters.In Experiment 1,the N170 neural adaptation at the left PO7 electrode was sensitive to the repetition of the phonetic radical,and the repetition of the character's pronunciation,but not to the repetition of both.These results indicated the left mid-fusiform gyrus might be sensitive to the visual/orthographic and phonological processing but not to the orthography-to-phonology mapping in Chinese character reading.In Experiment 2,the N170 neural adaption at the left PO7 electrode was only sensitive to the repetition of the character’s meaning,which indicated the semantic processing might modulate the left N170 in character reading.The N170 neural adaption at the right PO8 electrode was sensitive to the repetition of the semantic radical and the character's meaning,which suggested that right N170 was involved in visual/orthographic and semantic processing in reading characters.In sum,the findings showed that the N170 was involved in the visual/orthographic processing and engaged in the phonological and semantic processing in Chinese character reading.Furthermore,the left N170 was sensitive to the character's phonological and semantic information,whereas the right N170 was sensitive to the character’s meaning and its semantic radical.