Language Control In Bilingual Speech Production

As bilinguals increase in number these years, bilingual speech production (henceforth BSP for short) has evolved into a hot topic in the psycholinguistic studies. BSP, furthermore, zeroes in on the issue of language control. Language control on the one hand distinguishes BSP from monolingual speech production; on the other hand it instantiates the general cognitive control of human beings in language use. Studies on language control in BSP can not only enrich our knowledge of speech production in particular, but also enhance our understanding of the control mechanism in human cognition in general.The literature review shows that four models of language control in BSP have been proposed:Inhibitory Control model, Language-specific Selection Model, Conceptual Selection Model and Language-specific Selection Threshold Model. These models can be further classed under such three headings as Group of Inhibitory Control, Group of Non-inhibitory Control and the Group of Compromise. A critical examination of these groups indicates that to clear up confusions over language control in bilingual lexical production and spell out its mechanism, further studies must be undertaken1) to reveal whether or not inhibition works;2) to identify the levels of processing (loci) at which inhibition is implemented if inhibition does work;3) to clarify whether or not inhibition ceases to work or varies in intensity with changes in L2proficiency, and4) to clarify whether or not inhibition ceases to work or varies in intensity with changes in speech production context.The dissertation carries out a theoretical discussion of the above-mentioned four issues and formulates six verifiable research hypotheses. In what follows, two experimental paradigms---repetition priming and retrieval practice paradigm are chosen and three experiments are designed and conducted to test the hypotheses.The conclusions our research arrives at are as follows:Inhibition works in the process of Chinese English learners’ speech production. Its role won’t disappear with the change of target language, L2proficiency or production contexts. Nonetheless, the inhibition of L1in L2production weakens as L2proficiency is raised and the inhibition in bilingual contexts is more noticeable than that in monolingual contexts. The loci of inhibition reside on the formal level of non-target language’s words, including phonological form and orthographic form.The results of our study confirmed some of the existing findings and extend the relevant research both theoretically and empirically. They are significant in evaluating the existing four models, and help us to fully appreciate the complex interaction of the two languages involved in BSP. They also provide implications for our reappraisal of the effect of foreign language learning and bilingual advantage of cognition.