On the representation of multiple languages in the brain: old problems and new directions

This paper has attempted to show that when the relevant literature is critically scrutinized there is very little evidence for the idea that the right hemisphere participates in multiple languages in any way significantly different from the case of a single language. We have seen that most of the clinical data support the simple notion that the left hemisphere controls the first and subsequent languages to the same degree. The experimental data are full of contradictions, but many of the claims are invalid due to various methodological and analytical problems explained previously. It is suggested that future research concentrate on finer-grained questions than simply whether a language is left lateralized or not. These questions should make connections with other known neurological and neuropsychological facts. Of primary interest is obtaining converging evidence on the hypothesis of differential cerebral territories within the left hemisphere of bilinguals for different languages. In conclusion, we would be wise to consider the bilingual as a very rich potential source for testing various hypotheses about linguistic and neurolinguistic organization. But we should not lose the opportunity to test both more general and more specific hypotheses to which the multilingual gives us access. If treated with care the multilingual will tell us much, even though he may speak in many tongues.