2 Studies about bilingualism and second language acquisition have a long tradition within linguistic and psycholinguistic research. With the global population becoming more and more multilingual and the recent proliferation of research in cognitive neuroscience, an increasing number of studies examining the way our brain is able to learn, represent, and handle more than one language at the same time are currently available. But few attempts have been made to transpose psycholinguistic models of second language acquisition (SLA) into functional neuroanatomic models. An important problem that arises when pursuing this goal is partially due to the delay in the development of cognitive neuroscience of language compared to psycholinguistics. In general, neurolinguistic models focus on very broad and general questions about bilingualism, while psycholinguistic research is already at the stage of addressing more specific and fine-tuned questions. This Granularity Mismatch Problem The contributions from psycholinguistic research are crucial to the improvement of neurolinguistic models. This importance stems from the fact that psycholinguistic research is posing more specific questions than those in many current cognitive neuroscience studies. For example, in the present issue we have several examples of the type of questions that psycholinguistic research can raise. In general, most of the work on morphosyntactic research from neuroscience and psycholinguistics has come from studying English, a language that has a relatively simple morphological system. However, the picture becomes more intricate when these models are extended to more complex morphological systems. The contributions in this journal issue embrace the complexity of different languages both in the role of the L1 background and from L2 processing perspective. They describe results in perception an
