Neural signatures of inhibitory control in intra-sentential code-switching: Evidence from fMRI.

In this study we examined the neural control mechanisms that are at play when habitual code-switchers read code-switches embedded in a sentence context. The goal was also to understand if and to what extent the putative control network that is engaged during the comprehension of code-switched sentences is modulated by the linguistic regularity of those switches. Towards that goal, we tested two different types of code switches (switches at the noun-phrase boundary and switches at the verb-phrase boundary) that despite being both represented in naturalistic corpora of code switching, show different distributional properties. Results show that areas involved in general cognitive control (e.g., pre-SMA, anterior cingulate cortex) are recruited when processing code-switched sentences, relative to non-code-switched sentences. Additionally, significant activation in the cerebellum when processing sentences containing code-switches at the noun-phrase boundary suggests that habitual code-switchers might engage a wider control network to adapt inhibitory control processes according to task demands. Results are discussed in the context of the current literature on neural models of bilingual language control.