二语和母语提取干扰效应的神经认知差异研究

The Study on the Neuro-Cognitive Differences between the L2 and L1 Retrieval Interference Effects

本研究采用ERP手段考察了二语和母语提取干扰效应的神经认知差异。研究有以下发现:首先,二语学习者和母语者就提取干扰效应表现出了相似的脑电模式,当不存在提取干扰时,句法违反引发了P600,当存在提取干扰时,句法违反引发了N400;其次,二语和母语提取干扰效应均表现出了不对称特征,提取干扰只能影响语法错误句的加工,引发振幅更大的N400和P600,但无法影响语法正确句的加工;再者,当存在提取干扰时,二语学习者句子加工引发的N400振幅高于母语者,而当不存在提取干扰时,母语者句子加工引发的P600振幅高于二语学习者。希望本研究能为建构母语和二语句子加工模型提供提取干扰机制方面的神经认知依据。

Retrieval interference effects are observed when items occurring between a head and a dependent overlap with either(or both)syntactic or semantic features of the dependent.For example,in the sentence such as"The author of the books were very famous",the verb"were"erroneously agrees with the noun phrase"the books"because they overlap with plural features.The present study attempted to use the ERP technique to investigate the neuro-cognitive differences between the L2 and L1 retrieval interference effects.The findings of the experiments were as follows:Firstly,L2 learners showed qualitatively similar ERP patterns of retrieval interference effects with native English speakers,in that ungrammatical sentence without retrieval interference(such as"The author of the book were very famous"),compared with grammatical sentence without retrieval interference(such as"The author of the book was very famous"),elicited a P600 effect;whereas ungrammatical sentences with retrieval interferences(such as"The author of the books were very famous"),compared with grammatical sentences with retrieval interferences(such as"The author of the books were very famous"),produced an N400 effect;Secondly,similar to native speakers,L2 learners also showed an asymmetrical pattern of retrieval interference effects,in that retrieval interferences only impacted ungrammatical sentences,eliciting larger N400 and P600 effects,but they did not cause any difficulty in processing grammatical sentences;Lastly,there were quantitative differences in the ERP profiles between L1 and L2 retrieval interference effects,in that the amplitudes of P600 elicited by native speakers were larger than L2 learners,however,the amplitudes of N400 elicited by L2 learners were larger than native speakers.We proposed that these two ERP components reflected two streams of syntactic processing:the P600 effect indexed full,combinatorial process which parsed morpho-syntactic features between agreement controllers and targets in the absence of retrieval interferences,while the N400 effect indexed a shallow,heuristic process which evaluated lexical associations between agreeing elements in the presence of retrieval interferences.The overall results were consistent with hypotheses given by Cunnings(2017)that highly proficient L2 speakers construct similarly specified syntactic parses as L1 speakers,and that differences between L1 and L2 processing can be characterized:1)L2 learners being more prone to retrieval interference effects than native speakers;2)L2 speakers placing more weights on lexical cues,but native speakers placing weights on morphosyntactic cues during retrieval operation.Moreover,the asymmetrical pattern of retrieval interference effects could be explained by the cue-based memory retrieval model.According to this model,a searching process would be initiated to find a possible controller of syntactic relationship when encountering a verb.In the case of ungrammatical condition with interference effects,the plural local noun overlaps in number features with the ungrammatical verb and therefore is likely to replace the singular head noun as the controller of agreement.However,in the condition of grammatical sentences,an agreement dependency can be established between the subject head noun and the verb due to their matching singular number feature.In this case,the plural local noun will have no more chance to interfere with the already established agreement.