成人第二語字彙處理系統之終點成就：高程度中文學習者案例研究

Attainability of a Native-like Lexical Processing System in Adult Second Language Acquisition: A Study of Advanced L2 Chinese Learners

第二語習得的成功與否，往往取決於第二語學習時間點上的差異。接觸第二語的時間越晚，語言學習終點成就的個體差異就越大；即使擁有充分的學習動機並身處在豐富的語料環境中，第二語成人學習者往往和母語使用者存在著質或量上的差異。這些差異不只會浮現在第二語學習者的語言表徵上，也會彰顯在第二語學習者的語言處理上；甚至高程度第二語學習者仍會在這兩個層次上表現出與母語使用者的細微差異。本研究針對一群在語言學習關鍵期後才開始學習中文的高程度第二語學習者，設計了兩個限時閱讀測驗。藉由探討高程度學習者的第二語識字過程，我們得以窺探他們在第二語字彙處理系統的終點成就。本研究發現這些高程度第二語學習者，在識字過程中雖然和母語人士採取同樣的字義理解程序，但在此過程中所激發的字彙心理表徵卻不盡相同；這群高程度學習者無法在字義理解過程中迅速地運用字彙聲調資訊激發字義。本研究認為雖然這個細微差異並不至於影響句子訊息的理解，但對辨識第二語書寫文字字意的速度和精確度，甚至對於閱讀內容的記憶都有負面的影響。

Considering the differential successes and failures in adult second language acquisition (SLA), many researchers have urged that studies on L2 ultimate attainment should identify the domains in which adult L2 learners are (or are not) able to attain native-like proficiency levels, hence providing a descriptive basis for the learning potential in adult SLA. In particular, both Birdsong (2005) and Sorace (2005) contend that at the L2 end-state, the fundamental difference between native speakers and highly proficient late L2 learners often reside in the processing system, thereby leading to minor quantitative and/or qualitative departures from monolingual norms. To test the above claim, this study explored whether a nativelike lexical processing system can be attained by advanced L2 learners who start acquiring Mandarin Chinese as a foreign language long after the onset of puberty. To this end, the study employed the advanced-learner approach, recruiting 23 adult L2 Chinese learners, whose L2 reading skills were comparable to native Chinese speakers, and 23 native speakers of Chinese as controls. Two online reading tasks that aimed to tap into sentence-level Chinese character recognition were administered to the participants. Data revealed that, while the two groups were comparable in terms of their overall Chinese reading ability, both similarities and differences co-existed between them with regard to the underlying lexical processing procedure and the nature of the activated lexical information; nevertheless, these L2 learners were still able to achieve functional equivalence with natives at the performance level. Based upon these findings, implications for L2 end-state lexical processing system will be discussed.