After a review of the literature on the use of brain-imaging techniques in the study of conference interpreting, the paper reports on a preliminary fMRI study in which 6 student interpreters alternated between simultaneous interpreting from Spanish into German (B into A) and free speech production in German (A language). Significant statistical differences were found between the two activities, and active brain areas were identified for each. One finding which raises interesting questions is that a brain area specialized in hand movement was activated during SI.