Bilingual lexicon
With the amount of bilinguals increasing worldwide, psycholinguists have begun to look at how the brain represents multiple languages. The mental lexicon is a focus of research on differences between monolingual and multilingual brains.
Research during past decades shows that bilingual brains have special neural connections, and whether they constitute a distinct bilingual brain structure is still being studied. The mode of basic lexical representations of bilingualism has also been debated.
Development
Lexical development
Lexical development does not occur in isolation. Children learn pronunciation, meanings and usage of words by interacting with their parents and environment, and through media like television, the Internet and social media. The process moves from using words in particular situations to the understanding that words can be used to refer to different instances of conceptual categories, like objects, or that action words can be used in similar situations. Later, children increase their vocabulary in categories like colour, animals, or food, and learn to add prefixes and suffixes to words, thereby expanding their meaning. Once children enter school, they apply and develop words into reading and written aspects. Knowledge will be developed through reading and exposure to various written contexts.Lexical development in bilingual children
Bilingual children's language development throughout childhood influences the lexical size of both languages. Researchers have shown that the basic process of learning is the same as that of monolinguals, and bilingual children tend to learn languages like two monolinguals. The growth of bilingual lexicons is the same as that of monolinguals. Older children tend to show greater cross-linguistic influence from their first language more than younger children. In this method of learning words, the vocabulary size is related to the time of exposure in that language. This will continue until a certain amount of vocabulary in that language is reached. Semantic tasks for preschool children with predominantly Spanish-speaking, English-speaking and balanced bilingual backgrounds showed that they are different from each other. Bilinguals perform best on expressive functions for both Spanish and English as well as predominantly-speaking children, but they performed differently in each language, meaning that they do not mirror equal performance in Spanish and English. One group performed better in English while another performed better in Spanish. The ability to learn one language does not influence the ability to learn the other for bilinguals.Lexical development in children who learn their second language when their first language is already developed is different from that of children who grew up in a bilingual environment. The first step of learning words in the second language is translation, or learning the definitions of those words. This is different from how they learned their first language, which involves taking information input from semantic and formal entities. When accessing these newly learned words, the basic language semantic system will be activated, which means that when a word in a second language is activated, the word in the dominant first language with the same meaning is also activated. Researchers say that learners are still thinking in their first language but try to represent their thought process in the second language through translation. As more semantic and syntactic knowledge for the second language is acquired, this new language gradually becomes independent from the first language. Learners begin to access the language without translation using the semantic knowledge for that language. As learners gain more and more exposure to the new language, they will complete the development of the second language when they can access and use the language from the concept, which can be said to be thinking in that language directly.