不同熟练程度藏汉双语者言语理解中的语码切换及其代价

以母语为藏语，第二语言为汉语的熟练和非熟练藏汉双语者为被试，采用词汇判断任务，在无切换、预期切换和无预期切换三种条件下，考察藏汉两种语言之间的语码切换及其切换代价。结果表明：（1）在三种条件下，熟练和非熟练藏汉双语者对汉语词的反应时均显著短于对藏语词的反应时，汉语词的错误率也显著低于藏语词；（2）切换条件下的反应速度显著慢于无切换条件，切换条件下的错误率显著高于无切换条件，存在显著的切换代价；（3）熟练藏汉双语者对汉语词的反应时显著短于非熟练藏汉双语者，熟练藏汉双语者对汉语词反应的错误率也显著低于非熟练藏汉双语者。本研究表明，藏汉双语语码切换过程中存在切换代价，支持抑制说；熟练藏汉双语者语码切换代价更小。

Language Switching and Switching Cost in Language Comprehension of Tibetan-Chinese Bilinguals With Different Proficiency Levels

In this study, we chose Tibetan-Chinese bilinguals to perform the word recognition task. For these bilinguals, Tibetan is their mother tongue and Chinese is their second language. According to the level of Chinese of the subjects, we divided them into two groups, that is, the proficient and nonproficient bilinguals. In this experiment, we set up three conditions, namely, the no switching, expected switching, and no expected switching conditions. The aim of this study is to determine the essentials of language switching and switching costs between Tibetan and Chinese. The results were as follows:1) under the three conditions, the reaction times of Chinese words of proficient and nonproficient Tibetan-Chinese bilinguals were significantly shorter than that of Tibetan words, while the error rate of Chinese words was significantly lower than that of Tibetan words. 2) Compared switching condition with no switching condition, the reaction speed of the former was slower, the error rate of the former was higher, they all reached a significant level. The switching costs were observed. 3) Compared proficient Tibetan-Chinese bilinguals with nonproficient Tibetan-Chinese bilinguals, the reaction times of Chinese of the former were shorter, the error rate of the former was lower, they all reached a significant level. For conclusion, in the process of Tibetan-Chinese bilingual's language switching, there was switching cost. The findings support the hypothesis of inhibition that the switching cost of proficient Tibetan-Chinese bilinguals was smaller.