Suggests that code-switching is not only a neurolinguistic process but also a psychological phenomenon with substantial reference to personality structure and dynamics. The bilingual's personality as a "code-switcher" is tentatively defined. (Author/CB)

Reviews research on the psycholinguistic processes underlying second-language learning, especially as it relates to the concept of interlanguage and the contributions made by sociolinguistics, neurolinguistics, and cognitive psychology. (MSE)

Presents data on the past and present state of research on the interlanguage hypothesis, with specific attention to its extension to children. Outlines a dual approach to developing a theory of second language acquisition--a macrobehavioral approach and a neurofunctional approach. Finally, problems for the interlanguage hypothesis are discussed.…