The impact of Relative Language Distance on Bilingual Language Control – a functional imaging study

Cross-linguistic activation is unavoidable in bilinguals and they require language control to manage it. In this study, it is posited that Relative Language Distance (RLD; the extent of lexical feature-similarity between bilinguals’ languages) can affect the extent of cross-linguistic activation and hence influence bilingual language control. This was investigated via an er-fMRI word-translation task on three similar bilingual groups but with varying RLDs: Dutch-English (low-RLD), Hindi-English (intermediate-RLD) and Cantonese-English (high-RLD). Cross-linguistic conflict and the degree of conflict monitoring/control necessary to manage it were expected to increase with decreasing RLD across groups and be appropriately reflected in the activity of conflict monitoring/control neural regions, such as the ACC (anterior cingulate cortex). Analysis revealed a significantly differential ACC response across the groups, reflecting its adaptation to differential conflict monitoring/control demands generated by RLD. The findings provide emerging evidence for RLD as a dimension of bilingualism impacting bilingual language control processes and neurobiology.