Bilingual Cognitive Control in Language Switching: An fMRI Study of English-Chinese Late Bilinguals

Abstract

The present study explored the bilingual cognitive control mechanism by comparing Chinese-English bilinguals’ language switching in a blocked picture naming paradigm against three baseline conditions, namely the control condition (a fixation cross, low-level baseline), single L1 production (Chinese naming, high-level baseline), and single L2 production (English naming, high-level baseline). Different activation patterns were observed for language switching against different baseline conditions. These results indicate that different script bilingual language control involves a fronto-parietal-subcortical network that extends to the precentral gyrus, the Supplementary Motor Area, the Supra Marginal Gyrus, and the fusiform. The different neural correlates identified across different comparisons supported that bilingual language switching involves high-level cognitive processes that are not specific to language processing. Future studies adopting a network approach are crucial in identifying the functional connectivity among regions subserving language control.

Brain Circuit for Cognitive Control Is Shared by Task and Language Switching

“…Note that some previous studies presented the language cue simultaneously with the stimulus (e.g., Abutalebi et al, , 2013Garbin et al, 2011;Guo et al, 2011) whereas others, including this study, presented the cue slightly before the stimulus (200-400 msec; e.g., Ma et al, 2014;Hernandez, 2009;Wang et al, 2007Wang et al, , 2009Hernandez et al, 2000Hernandez et al, , 2001. We think that both approaches have advantages and disadvantages.…”

“…One possible interpretation for the absence of the caudate in the current study is that it is a consequence of the use of three different languages and the associated distribution of switch and repeat trials in the different languages. In a recent study, Ma et al (2014) found the caudate when contrasting the switch condition with a simple naming condition in L1. However, the caudate was not observed when comparing the switch condition with a simple naming condition in L2.…”

“…However, the caudate was not observed when comparing the switch condition with a simple naming condition in L2. Ma et al (2014) concluded that the caudate is involved in conditions that require much inhibition, hence in language switching and during the L2 naming condition, when inhibition of L1 is necessary. Consequently, the caudate should also be involved during L3 naming.…”

Bilingualism at the core of the brain. Structural differences between bilinguals and monolinguals revealed by subcortical shape analysis

“…Right-lateralized activity in the caudate nucleus has been reported during a language switching task in Chinese-English bilinguals (Ma et al 2014) and, in a meta-analysis of language switching studies, Luk et al (2012) showed the implication of both right and left striatal structures.…”

Redefining bilingualism as a spectrum of experiences that differentially affects brain structure and function

“…Such an interpretation is supported by the contractions seen in the bilateral thalamus, which indicates a decreased reliance on this structure with increased efficiency in language selection (19,31). The left caudate nucleus is more often implicated in language and task-switching cognitive demands (6); however, several studies report recruitment of the right caudate for more demanding language-switching tasks (59,60). Regarding the predictions of the ACH, we may interpret the right caudate and thalamic contractions as a marker of decreased requirements for gating the interfering language.…”