基于ERP的二语句子加工过程的认知神经机制研究进展及其启示

The Advance and Implication of ERP Researches on Neurocognitive Mechanisms of Sentence Processing in Second Language

二语句子加工认知神经机制的研究基本上还集中于对一语和二语的语义违例与句法违例反应的比较。就二语语义加工而言,所得结果充满矛盾,这可能与二语习得年龄有关。二语句法加工过程依赖于二语熟练度以及语言间的句法相似性。应当系统考察语义通达程度和句法通达程度的系统变化对二语加工可能会造成怎样的影响,重视那些充分体现二语句法结构的根本特点的句法信息的加工所引发的认知神经活动,同时探明工作记忆、语言加工策略等认知因素对二语句法加工是否具有根本的影响。

Beginning with the pioneering work of Kutas and Hillyard, a large body of evidence has demonstrated that scalp - recorded event- related brain potentials （ERPs） are sensitive to particular aspects of sentence processing （MeKinnon ＆ Osterhout, 1996 ）. Compared with reaction paradigm, ERP can provide the reaction times and scalp activities without interference from task performance and subjects＇conscious judgments, so we can take a time -locked online measurement. The data of the experimenters can be analyzed offline, tightly combining the cognitive processes of sentence processing and underlying neurophysiologic activities. Now, ERP researches in sentence processing have provided implications for the neurocognitive mechanisms of first language pro- cessing. Researchers confirmed that semantic and syntactic anomaly elicits ERP components of different nature （ e. g. , semantic anoma- ly evokes 51400, syntactic anomaly involves ELAN,LAN and P600） and thereby constructed a more persuasive neurocognitive model or theory, which greatly advanced the researches in the field. However, compared with first language researches, researches in second language processing is at the stage of exploration and veri- fication. The findings of semantic processing from second language ERP researches were identical with those of first language resear- ches： semantic anomaly evokes N400 but the amplitude was smaller than that of native speakers, its latency was somewhat delayed. Some researches even indicated that there was no difference between first and second language. By contrast, findings about second lan- gnage syntactic processing were inconsistent with those about first language. Many researchers found that, for late second language learners, second language proficiency and the similarity between first and second language directly influenced second language compre- hension, but for specific finding and theoretical explanation, discrepancies remained. Two keys to the question lie in ： first, previous re- searches paid little attention to how second language learners understand syntactic structures of second language. Taking English for ex- ample, recent ERP researches mainly involved phrase structure and subject - verb agreement, but not some important morphology and grammatical structures, e. g. , voice and mood, which failed to be greatly generalized. Second, a series of researches have confirmed syntactic processing of second language was influenced by similarities between syntactic structures and language proficiency, but it re- mains unknown as to which one holds priority. Furthermore, most of related studies were done in English and other Indo - European languages with close relation to English as subjects＇native languages （for instance, German, Dutch, and Spanish）, or English as their second or foreign language, less attention was paid to Chinese ESL learners. It is well known that Chinese is an ideograph with no mor- phological changes, while English has a rich morphological body. A good case in point is the inflected form of a verb besides the gender and number agreement. Will these great differences lead to specific characteristics in neurocognitive mechanisms of Chinese ESL leam- ers＇sentence processing？ Studies on the mechanism of Chinese ESL learners second language processing can provide the new and useful clues for sentence comprehension. Future studies should focus on the effects of systematic changes of semantic and syntactic accessibility on second language process- ing, emphasizing the neurocognitive mechanisms related to processing of syntactic information reflecting the fundamental characteristics of second language syntactic structures. In addition, it is necessary to probe into whether working memory and language processing strat- egy have essential influence on syntactic processing.