Studies in bilingualism come from 3 main disciplines; psychology, applied linguistics and education. Psychologists are interested in brain functioning and cognitive processing, linguists are interested in the way individuals and groups develop and use language and educationists are interested in language teaching and learning in classroom settings as well as assessment.
Memory can be divided into echoic memory, short-term (working) memory and long-term memory. Long-term memory can be subdivided into episodic, semantic, procedural and declarative. In the same way, multiple languages in a brain can be divided into separate language systems. It means, each language system in the brain of a multilingual can be represented by systems that are able to function independently of the other language systems.
Unilingual structure in the brain of a monolingual user consists of separate subsystems, namely the phonological, orthographical, syntactical, contextual and lexical systems. Modularity theory posits that even though these different subsystem work together in a single language system, they are independent of each other. Language processor is modular; (meaning it is designed with standardized units or dimensions) as for easy assembly and repair or flexible arrangement and use, whereas episodic memory is non-modular; and it is sensitive to the intention to learn and to other motivational variation.
The level of lexical representations was traditionally thought to refer to the semantic description of individual words.
One of the earliest bilingual models classifying bilinguals into coordinate bilingualism, subcoordinate bilingualism or compound bilingualism.
In coordinate bilingualism, the word of 2 languages are kept separate in different conceptual systems and each word (in each language) has its own specific meaning. In this case, the languages are independent of each other. In subcoordinate bilingualism, the first language takes the position of the dominant linguistic system and the linguistic system of the second language is attached to that of the first language. In compound bilingualism, the word of both languages are attached to the same mental representation; i.e. 2 different verbal labels are attached to a single concept. In this case, the languages are interdependent only at the conceptual level.
By: Hong Ee-Li & Rita E. Silver.
Declaration: This is based on my reading on the article entitled The Psychology of Bilingual language Acquisition. Written by: Hong Ee Li & Rita E. Silver. The whole passage is taken right from this article, courtesy to these authors. It is shared for the purpose of dissemination of knowledge. No profit motive involved.