Marian, V., Faroqi-Shah, Y., Sheng, L., Shildkrot, E. & Hirsch, J.  (2002).  One brain, two languages: Cortical similarities and differences in bilinguals. Proceedings of the American Psychological Association, Division 40. The Clinical Neuropsychologist, 16, 195.

Abstract:

Volumes and centers of cortical activation in the IFG and the STG were compared during first and second language processing in Russian-English bilinguals.  fMRI images of the brain were obtained while participants listened to and read words and non-words.  Results revealed that L2 activated a larger cortical volume than L1 during semantic and phonological processing, that the left hemisphere showed more activation than the right hemisphere during semantic processing, and that L1 and L2 activated different centers in the IFG, but not the STG. These results have implications for bilingual aphasia, neurosurgery, and speech and language therapy for bilingual patients.