This interpretation is consistent with behavioral research suggesting that executive control mechanisms may
be more efficient in bilinguals compared find more to monolinguals (e.g., Treccani, Argyri, Sorace, & Della, 2009). Most relevant to the current study are Blumenfeld and Marian’s (2011) findings that bilinguals’ (but not monolinguals’) inhibition of competing phonological information is associated with the group’s executive control ability. Here, we show that the behavioral differences observed between monolinguals and bilinguals in past research may indeed be driven by differences in how the groups recruit executive control resources at the neural level. Although monolinguals and bilinguals in our study did not differ in their behavioral Simon effect performance (as participants were young adults at their cognitive peak; see Hilchey & Klein, 2011), cortical changes attributed to language experience
emerge even in the absence of behavioral differences between groups (e.g., Bialystok et al., 2013 and Rodríguez-Pujadas et al., 2013). Accordingly, we observed significant correlations between performance on a non-linguistic competition task and cortical activation in regions associated with executive control during a linguistic competition task. Past research has demonstrated that non-linguistic competition is managed through the recruitment of frontal cortical regions including middle frontal gyrus (MFG; Fan et al., Sirolimus manufacturer 2003 and Maclin et al., 2001), superior frontal gyrus (SFG; Fan et al., 2003 and Maclin et al., 2001), Suplatast tosilate anterior cingulate cortex (ACC; Fan
et al., 2003, Kerns, 2006, MacDonald et al., 2000 and Peterson et al., 2002), and inferior frontal gyrus (IFG; Fan et al., 2003 and Peterson et al., 2002). When faced with linguistic competition, the bilinguals who were best at resolving non-linguistic competition were most likely to strongly activate this extended network of frontal regions. Specifically, correlations between non-linguistic competition resolution and the control of linguistic competition were found in bilateral MFG, bilateral SFG, right IFG, and ACC. This suggests that, in bilinguals, the substrates used to resolve linguistic and non-linguistic competition are highly related. In other words, bilinguals rely on inhibitory control processes that are modality- and task-independent. Monolinguals, in contrast, appear to rely on partially distinct mechanisms for the control of linguistic and non-linguistic competition. Unlike the bilinguals, for whom correlations emerged in multiple distinct regions associated with executive control (bilateral MFG, bilateral SFT, right IFG, ACC), monolinguals’ performance only resulted in significant correlations in right MFG. The finding that bilinguals’, but not monolinguals’, cortical control of linguistic competition is subserved by domain-general control mechanisms is consistent with both neuroimaging (Garbin et al.