The L1 Automatic Activation During L2 Word Processing:Evidence From Chinese Learners Of English

Vocabulary knowledge is a core component of language competence, and vocabulary acquisition plays a vital role in second language acquisition research. In recent years, with the integration with other disciplines such as psycholinguistics, neurolinguistics and cognitive sciences, vocabulary acquisition of second language has massively expanded its research field and has nurtured a series of new hot issues. One of them is the bilingual lexical automatic activation. Many studies have found out that the L1 may be automatically activated during the processing of L2 words. By far, the research of L1 automatic activation in L2 word processing has made great progress, yet there are still some limitations. In terms of research participants, most studies take second language learners with alphabetic L1 as participants, but little attention has been paid to English learners in China with non-alphabetic L1. In terms of research content, there is still a lack of comprehensive and systematic exploration on the locus (conceptual level/lexical level/sub-lexical level) and time course of L1 automatic activation. Methodologically, most studies have only used the basic reaction time (RT) technique rather than the event-related potentials (ERP) technique, which has a high temporal resolution and is able to make a real time record of the cognitive processing. Besides, the cross-language tasks that have widely been used provide a bilingual context themselves and bias toward a dual-language activation pattern, which may lead to participants’ conscious rather than automatic activation of L1 and hence result in interference to the observation of L1 automatic activation. Theoretically, most of the theoretical models have been proposed based only on the studies on alphabetic languages. It needs verification whether or not these models can be applied to the ideographic languages such as Chinese, but little research has worked on it.Regarding these facts, the present study intends to investigate the L1 automatic activation during L2 word processing of the highly proficient and unbalanced Chinese-English bilinguals (Chinese learners of English), by combining RT technique and the ERP technique, and applying the semantic relatedness judgment task and masked lexical decision task. The research questions involve:(1) Where is the locus of L1 Chinese automatic activation during L2 English processing? That is, at which level or levels (conceptual level/lexical level/sub-lexical level) does the activation take place? What is the difference in activation locus between the deep processing and shallow processing? (2) What characterizes the time course of L1 Chinese automatic activation during L2 English processing? That is, what are the features of the activation at the early and the late stages of L2 English processing respectively? What is the difference in activation time course between the deep processing and shallow processing?To answer these questions, two experiments have been carried out. Experiment 1 was a semantic relatedness judgment task. Twenty-one participants judged whether the prime words and the target words were semantically related. Experiment 2 was a masked lexical decision task. Fourteen participants judged whether the target words were real words. The core materials in the two experiments were the same 210 English word pairs. Half of them were semantically related while the other half were not. Although these English word pairs did not share any morphological repetition, their Chinese translation equivalents eventually concealed a hidden repetition of the first character, repetition of the second character or no repetition. Thus, the manipulation of the two variables came to a within-subject 2 (semantic relatedness: related vs. unrelated) x 3 (hidden character repetition:first character repetition vs. second character repetition vs. no repetition) factorial design. Based on this design, the semantic relatedness was manipulated to measure the L1 automatic activation at the conceptual level and the position of hidden character repetition was manipulated to measure the L1 automatic activation at the lexical and sub-lexical levels. The ERP components N400 and LPC were extracted to measure the L1 automatic activation at the early stages and the late stages respectively. The SOAs of the first and the second experiment were set 700ms and 67ms respectively, in order to investigate the L1 automatic activation in deep processing and shallow processing.Based on the analyses of the RT and ERP data, the following findings have been revealed:(1) In shallow processing, no semantic priming effect or hidden repetition priming effect was observed. However, in deep processing, there was significant effect of semantic priming and hidden repetition priming when Chinese learners of English were processing L2 words. It indicated that L1 Chinese automatic activation took place at the conceptual level, lexical level and sub-lexical level. That is to say, L2 word processing was accompanied with multi-level L1 automatic activation. The results supported the predictions of hierarchical structure of bilingual mental lexicon in the BIA+model. Besides, the asymmetry of hidden character repetition effect at the sub-lexical level has been found out for the first time. That is to say, the effect" of the hidden character priming of the second character was more salient than that of the first character, which indicated that the automatic activation of the second character was stronger than the first character.(2) In shallow processing, no ERP effect was observed. However, in deep processing, there was significant N400 effect at the early stages and LPC effect at the late stages during L2 word processing of Chinese learners of English. It indicated that the L1 Chinese got automatically activated quickly at the early stages during L2 English processing and last for a relatively long time to the late stages. Take the above mentioned findings into consideration, it could be inferred that in L2 word processing, the visually input L2 word forms activated the concepts first, which subsequently activated the corresponding L1 word forms, and further activated the second character and the first character at the sub-lexical level. The L1 was not intended to be consciously activated but was the "by-product" of the activation of L2. The results supported the predictions of pathway of activation in the RHM model.In consideration that the above findings only partially fit the theoretical predictions of the mainstream models such as the BIA+ model and RHM model, the present study tentatively analyzed the features and limitations of the BIA+ and RHM models that were widely applied to alphabetic languages, and proposed the Extended Hierarchical Model (EHM), which was compatible with the features of Chinese. It turned out that this model could better account for the phenomenon of L1 automatic activation during L2 word processing of English learners in China.The contributions of the present study are mainly manifested in the following four aspects. (1) In terms of research participants, the investigation into the high proficiency unbalanced Chinese-English bilinguals enriched the types of research participants and provided more evidence for the universality of bilingual activation. (2) In terms of research content, this study made a comprehensive exploration of the three loci (conceptual level, lexical level and sub-lexical level), two time periods (the early stages and the late stages) and two processing depths (the deep processing and the shallow processing) of L1 automatic activation, which expanded the research dimensions of bilingual activation. (3) Methodologically, the measurement of this study involved the combination of two techniques (RT and ERP), which expanded the dimension of data collection. Furthermore, this study modified the hidden repetition priming experimental paradigm used in previous studies and designed a module of stimulus materials for the measurement of bilingual activation at the sub-lexical level, which provided methodological reference for the future research. (4) Theoretically, this study tentatively constructed the Extended Hierarchical Model of L1 automatic activation during L2 word processing. This model could be applied to account for the features and mechanism of Chinese-English bilinguals’ L1 automatic activation.