The Research Of N170 Expertise In Chinese Character Cognition

The research about variation of the brain acitivities which is related to the visual word form in the process of reading acquisition is important to understand the essence of reading processing. The investigation of the event-related potentials found that the N170 component in the visual word cognition was located in occipito-temporal area, in which the N170 amplitude of words was stronger than non-words, such as line drawings and strings, and this N170 component is left lateralization. But for the essence of the N170 component, most researchers considered that the N170 component was related to orthographic processing, but a few researchers held that the N170 component was modulated by speech or semantic. The conclusions of the study mainly come from the discussion of the letter languages, but Chinese character was different from the word in letter languages. In physical visual features, Chinese characters were composed by different number of components. In the level of languages, the orthography of Chinese characters was more complex than the words in letter languages, and Chinese characters basically didn't possess the grapheme-to-phoneme conversion which existed in letter languages. And, most researches showed that the reading mechanism of Chinese characters was different from the brain mechanism of the letter reading languages. Consequently, it is important to discuss the N170 component in the cognition of the Chinese characters which not only figured out the controversies of the N170 results in letter languages, but also provided an opportunity to investigate the universality in the letter processing theory and the specifility in Chinese characters' processing.Therefore, we used implicit reading task to study the specialization and lateralization of the N170 component of the Chinese characters. In our researches, there were two experiments. In the first experiment, we utilized Chinese character, face drawings and object drawings as stimuli materials in order to investigate the selective category of the N170 component in the Chinese characters. And, in the second experiment, we used two experimental paradigms that were color discussion task and repeat decision task, to systemically study the specialization and lateralization of the N170 component in the Chinese characters, in which the materials were high frequent characters of Chinese, low frequent characters of Chinese, pseudo-words and combined strokes.The results showed that:(1)In the left brain, the N170 components which were activated by the processing of the Chinese characters were much stronger than the N170 components of object drawings. And this indicated that the N170 components activated by Chinese characters were expertise, at the same time, the N170 components were left lateralization.(2) Compared with the color decision task, the N170 components activated by Chinese characters in the repeat decision task were much stronger. And, this indicated that the N170 components activated by Chinese characters' processing were modulated by the degree of the attention.(3)In the left brain, the N170 components activated by high frequent characters of Chinese, low frequent characters of Chinese, pseudo-words were much stronger than combined strokes' N170. And, this result revealed that the N170 components of Chinese characters were related to the components themselves of orthography rather than components' location.