The ERP Research On The Recognition Of Chinese Characters By Structural Closure

Chinese characters, as a written symbol system, is a tool for recording and transmitting culture. Different from alphabetic words, Chinese character is a kind of hieroglyphs, the basic attribute of Chinese characters is its shape and structure. According to the different method, Chinese characters have different structure. The so-called closed word here refers to any word that has a closed interval. It is a kind of special structure of Chinese characters and the proportion is very limited in the total amount of Chinese characters. Therefore, so far, research on closed structure of Chinese characters is minimal. In this study, a series of experiments on the closed structure of Chinese characters and the general non closed structure of Chinese characters are compared, to explore whether this particular structure of Chinese characters has its particularity of cognitive processing.For a long time, the EEG component N170, P200 and N400 were thought to be related with the vocabulary of cognitive processing. N170 reflects the processing of Chinese characters in the early stages of visual processing, affected by the knowledge and experience of experts. P200 is thought to be related to the shape, pronunciation and sub-lexical processing, influenced by the size of the family orthography. N400 is generally considered related to semantic processing, is also affected by the size of the family orthography. Compared to the ordinary non closed structure of Chinese characters, closed characters since the periphery has surrounded by a closed interval, on one hand, they have great difference in appearance, and on the other hand, their true family(with closed word has same structure of family members) size are not the same. These features may lead to that their processing mechanism is not the same. The current research will also benefit from N170, P200 and N400 these classic EEG components which related word processing as a starting point for the closure and non-closure characters for comparison. Further from orthographic features, familiarity and orthography family size approach to understanding that the difference between a closed character and a non closed character in structural shape is how to lead to differences in the intrinsic mechanism of processing.Experiment 1(a), in order to collect and compare pure recording brain waves, we conducted the experiment using the closed structure of Chinese characters and non-enclosed structure of Chinese characters as experimental materials, through the experimental paradigm by rhyme judgment. Namely asked participants to make rhyme judgment with the character followed by “?” after compared it with “chun”, but they didn’t need to make any judgment with the character followed by “#”. In fact, all of the target stimuli were followed by “#”. The results show that two kinds of structure of Chinese characters in N170 and P200 components have been dissociated. Compared with the ordinary non closed structure Chinese characters, the closed structure of Chinese characters on P200 and N170 has caused much smaller amplitude.On the basis of Experiment 1(a), Experiment 1(b) made a slight change in the experimental task. Namely asked participants to make rhyme judgment with target stimuli after compared them with “chun” and press the button, in order to record the reaction time and accuracy. Results show that on the reaction time and accuracy, closed structure of Chinese characters have significant difference with non closed Chinese characters(reaction time: t = 2.66, p(19) < 0.05; accuracy: t = 3.26, p(19) < 0.01). Compared with non closed structure of Chinese characters, the participants to the closed structure of Chinese characters reaction time is longer, the accuracy is lower.On the basis of Experiment 1, in Experiment 2, we removed the unknown characters of which frequency is less than 0.00006% and used remaining stimuli as experimental material. Then we conducted the experiment through the rhymes judgment paradigm to react with target stimuli in order to record behavioral data and EEG data of participants at the same time. It was found that in the behavioral data, the reaction time of closed character is slightly higher than that of non closed word, but did not reach statistical difference, while in the accuracy, closed word was significantly lower than that of non closed word [F(1,19) =11.97, p < 0.01, MSE = 0.001, η2 = 0.39].On the EEG data, closed word in N170 and P200 still cause smaller amplitude than non closed word. And we also found that to N170, it seems that it’s more significantly on the right brain than on the left brain. In addition, we found the closed structure of Chinese characters caused a greater volatility on N400 component than non closed structure of Chinese characters.In Experiment 3, through the lexical decision task, we used the stimuli in Experiment 2 as true materials and created the same number of closed structure and non closed structure of pseudo words, formed a 2(closed: word closed and non closed word) x 2(true and false: characters, pseudo characters) within-subjects design. Results showed that on the behavior data, for closed characters, the reaction time was longer and accuracy was lower than non closed characters. For pseudo characters, reaction time is longer and accuracy is lower. In addition, on the reaction time, closeness and the character type have an interaction with each other, only under the condition of true words, closure effect is significant. EEG data is the same as the Experiment 2, in the early processing, closed characters evoked smaller N170 and P200 than non closed characters. And N170 on the right side of the brain was more significant. In the late processing, closed characters also evoked greater N400 amplitude than non closed characters.Conclusion:(1) As a special structure of Chinese characters, the processing mechanism of the closed structure of Chinese characters is different from the non closed characters, which is reflected on both the early visual processing and the late semantic processing. It’s more difficult to recognize closed characters;(2) In the processing of closed and non closed words, compared to the true family of strokes, the influence of the true family of radicals has more advantages;(3) Using different experimental tasks, the behavior results and ERP results of the closed structure of Chinese characters are basically consistent, which shows that the internal processing mechanism is relatively robust and reliable, and is not affected by the experimental task;(4)In the early visual processing on structure of Chinese characters, N170 component showed lateralization phenomenon, the right brain showed more advantages on processing than the left brain.