The aim of this research is to explore the neuropsychological underpinnings of two linguistic abilities, namely shadowing and simultaneous interpretation/paraphrasing, in a group of professional interpreters, individually paired with closely matched non-interpreter bilingual and monolingual controls. By including monolinguals, non-interpreter bilinguals and professional interpreters, the authors are in a position to determine whether cerebral asymmetries for interpretation or shadowing are differentially influenced by a) knowledge of more than one language and/or by b) skill or expertise for the task.