The Function Of Sub-lexical Units In Chinese Characters Recognition:An ERP Study

Visual word recognition is a complex process,its components including sub lexical components like strokes,radicals,phonological radical and semantic radical.It is very important to understand how these sub-lexical functions play an important role in Chinese character recognition.The smallest unit of the Chinese character is stroke.According to the MIA model,the processing of a Chinese character passes through three levels: strokes,radicals and whole character.Alphabetic comparison has no clear relationship between Chinese characters corresponding to the sound,but 80% modern Chinese characters have a semantic radical and a phonological radical.The phonetic radical provides voice information related to the Chinese characters helping identify the process of the whole word pronunciation,therefore the focus of our research on sub-lexical strokes and phonological radicals.The stroke number effect of previous researches are not taken into account orthographic neighborhood size,so we suspect that the orthographic neighborhood size affect the stroke number effect.In the phonetic study,researchers found English words pronunciation interfere the figure feedback leading bigger P200,and in Chinese characters,the phonological radical rules the whole character's pronunciation,so whether phonological radicals interfere the figure feedback leading bigger P200,we want to test it.In previous studies,P200 was mainly related to early phonology processing and figure processing.Combining previous studies,we found that the decrease of P200 reflects a degree of facilitation,and the increase of P200 is a difficulty in responding to the processing of a character.On this basis,we use ERPs,assuming that the P200 component will become smaller in strokes and phonological radical processing facilitation.We design the Experiment 1,we balanced the size of orthographic neighborhood.We expect that the stroke number effect will disappear,and because the number of strokes is small and processing is easy,a smaller P200 will be triggered.In experiment 2 of the phonetic neighborhood regular,it is expected that phonological radicals interfere the figure feedback leading bigger P200.In experiment 1,we used lexical decision tasks,and the experimental design was designed for single-factor subjects.There are three different character types.They are a small stroke(2 to 5),a medium stroke(6 to 9),and multiple strokes(10 to 13).The orthographic neighborhood size and frequency of the three types of strokes are balanced.The main consideration is whether the stroke number effect still exists after balancing the size of the stroke family.The experiment also has the same number of false words as the real words.The results show that:(1)Behavioral results: on the reaction time(RT),it showed a significant main effect.the m number of strokes to stimulate the reaction is the smallest,followed by the number of strokes,followed by more than the number of strokes.This research result is consistent with previous research on the effect of stroke number.In other words,after balancing the family size,the stroke number effect still exists.(2)EEG results: The study found that fewer strokes induced smaller P200 amplitudes than the other two conditions(multiple strokes and medium strokes).This confirms our expectation that the early sub-lexical processing facilitation led to a small P200.In experiment 2 we used the same word matching task,and the experimental design was 2(regular phonetic neighborhood,irregular phonetic neighborhood)* 2(regular,irregular word).Experimental results: The results show that under the condition of regular words,the regular phonetic neighborhood trigger a greater P200,which is consistent with our expectations.However,we have found a lateral inhibition mechanism.There are lateral suppressions under regular phonetic neighborhood target words,but they are internally cancelled;in the case of irregular words,the irregular phonetic neighborhood induces a larger P200 than the regular phonetic neighborhood because of lateral inhibition mechanism.With regular phonetic neighborhood,there is no difference in the size of the P200 caused by regular words and irregular words;in the case of irregular phonetic neighborhood,irregular words induce larger P200 than regular target words.The results of these studies show that the regular phonetic neighborhood has greater disturbance feedback than the irregular phonetic neighborhood,and therefore it triggers a large P200.Simultaneous inhibition caused by the lateral inhibition mechanism also induces a larger P200.Combining experiment 1 and experiment 2,the existence of sub-lexical unit strokes and sounds were confirmed,and it was proved that,unlike alphabetic characters,the effect of stroke number has nothing to do with the size orthographic neighborhood;The P200 EEG results of the two experiments also showed that the facilitation of the processing of the early sub-lexical would lead to a decrease of P200,whereas the processing difficulties would be an increase.