Domain-general inhibition areas of the brain are involved in language switching: FMRI evidence from trilingual speakers

- Trilingual speakers performed a language switching task in the MRI scanner.
- Language switching showed increased activation in the right IFG and pre-SMA.
- Bilinguals use domain-general inhibition areas to switch between their languages.

The prevailing theory of language switching states that unbalanced bilingual speakers use inhibition to switch between their languages (Inhibitory Control or IC model; Green, 1998). Using fMRI, we examined the brain mechanisms underlying language switching and investigated the role of domain-general inhibition areas such as the right inferior frontal gyrus (rIFG) and the pre-supplementary motor area (pre-SMA). Dutch-English-German trilinguals performed a picture naming task in the MRI scanner in both a blocked-language and a mixed-language context. The rIFG and pre-SMA showed more activation for switches to the second and third language (L2 and L3) compared to non-switch trials and blocked trials. No such difference was found for switches to the first language (L1). Our results indicate that language switching recruits brain areas related to domain-general inhibition. In this way, our study supports the claim that multilinguals use inhibition to switch between their languages.