Abstract: The present study investigated the relative importance of phonological short-term memory (PSTM) and lexical knowledge for second language (English) vocabulary learning in Chinese-English bilinguals. To clarify the conjoined influence of two factors, we distinguished PSTM into serial order STM (measured by serial order reconstruction task) and item STM (tested by delayed single nonword repetition), and nonwords were manipulated in phoneme familiarity (English nonwords and mixed nonwords). Participants are all Chinese native speakers who learn English as a second language with medium proficiency. The paradigm of picture-nonword pairs was adopted in this research. Using a learning way of auditory presentation and speech output, Experiment 1 demonstrated that nonword repetition and lexical knowledge are two independent predictors of familiar nonword learning; as for unfamiliar nonwords, lexical knowledge and serial order STM measurement independently predicted its performance. Since the results of Experiment 1 can be caused by learning difficulties and inaccuracy of pronunciation, picture recognition in the paired-associate learning were used in Experiment 2 to explore this question further. The results of Experiment 2 show that serial order STM, item STM and lexical knowledge are all independent predictors of familiar nonword learning, and serial order STM and item STM can also predict the performance of unfamiliar nonword learning independently. These results illustrate the important role of PSTM and lexical knowledge in second language vocabulary learning among Chinese-English adults, and the influence would varied since the characteristics of input information and ways of learning are different.

Key words: phonological short-term memory, lexical knowledge, vocabulary learning

摘要： 选取两种语音熟悉程度不同的非词为实验材料，把语音短时记忆区分为项目短时记忆和序列短时记忆，考察语音短时记忆与词汇知识对汉英双语者第二语言（英语）词汇学习的影响。实验1采用产出性的方式进行学习，结果发现，词汇知识与项目短时记忆对语音熟悉非词的学习起预测作用；词汇知识与序列短时记忆对语音不熟悉非词学习起预测作用。实验2采用接受性的方式进行学习，结果发现，项目短时记忆、序列短时记忆和词汇知识都对语音熟悉非词学习起独立的预测作用；项目短时记忆和序列短时记忆对语音不熟悉非词学习起独立的预测作用。实验结果表明，语音短时记忆和词汇知识都是影响英语词汇学习的重要因素。具体而言，学习语音熟悉的词汇，词汇知识起着更为重要的作用；学习语音不熟悉的词汇，语音短时记忆、特别是序列短时记忆起着更为重要的作用，而且两者作用的大小随着词汇学习方式的不同而发生变化。

关键词: 语音短时记忆, 词汇知识, 语音学习