In the previous chapter I reviewed existing models of multilingual speech production focusing on how multilinguals produce overt speech in one language and at the same time control the additional knowledge that is also in the mind. Discussions focused on the various stages of processing and the selection and retrieval mechanisms that guide the overall production process. In this chapter the focus is shifted to the multilingual lexicon and what we know about the way multilinguals organize, store and associate linguistic knowledge in the mind.

As was the case with models on multilingual speech production, models of lexical representation that specifically focus on the multilingual lexicon and its processing operations are mostly extended versions of models of bilingual lexical representation. As noted in the previous chapter, adaptations of this kind generate advantages as well as disadvantages. On the one hand, hypotheses of bilingual lexical representation are based on a wealth of empirical data and therefore provide a firm base on which theoretical extensions can be made. On the other, a sound empirical base about the bilingual lexicon cannot adequately inform hypotheses about multilingual lexical organization as questions of direct relevance to multilingualism have not been specifically addressed. In this chapter we will see that only a few studies have addressed questions of direct relevance to multilingualism, and all of these are based on previous research on bilingual memory and bilingual lexical representation. Some review of research on bilingualism is therefore essential to understand the type of questions which have been raised about the multilingual lexicon over time.

The chapter is organized in five sections. The first provides an overview of research on bilingual and multilingual memory and discusses some implications and areas of future research of relevance to multilingualism. The second examines research on the relationship between proficiency level and lexico-semantic organization. The third introduces issues associated with storage capacity and the amount of information that is held in the mind.