A large body of knowledge has accumulated especially in the last three decades on the cognitive processes and brain mechanisms underlying language use, language acquisition, and language disorders. Much of this knowledge has come from studies of Indo-European languages, in particular, English. Some researchers believe that because of the universal principles of language, theories of language and language processing should apply in the same way to all languages even if they are built on facts from specific languages. Others, however, think that language-specific variations are sufficiently strong to warrant different conceptualizations of linguistic principles and cognitive underpinnings for different languages.
Unlike generative theories of language, this second perspective itself is a mixed bag, from the strongest form of the Sapir-Whorf hypothesis that argues for linguistic determinism to modern-day psycholinguistic theories that emphasize language variation and competition. The tension between these two perspectives has yielded much debate in the cognitive and psycholinguistic studies of language, and it is against this backdrop that we do our crosslinguistic research in lexical representation and ambiguity processing, sentence interpretation, and bilingual lexical and sentence processing.