Verbal and nonverbal cognitive control in bilinguals and interpreters.

The present study explored the relation between language control and nonverbal cognitive control in different bilingual populations. We compared monolinguals, Dutch-French unbalanced bilinguals, balanced bilinguals, and interpreters on the Simon task (Simon & Rudell, 1967) and the Attention Network Test (ANT; Fan, McCandliss, Sommer, Raz, & Posner, 2002). All bilingual groups showed a smaller congruency effect in the Simon task than the monolingual group. They were also faster overall in the ANT. Furthermore, interpreters outperformed unbalanced, but not balanced, bilinguals in terms of overall accuracy on both tasks. In the ANT, the error congruency effect was significantly smaller for interpreters and balanced bilinguals. Using a measure of switching fluency in language production, this study also found direct evidence for a relation between language control and executive control. This relation was only observed in balanced bilinguals, where fluent switching was correlated with the Simon effect. These findings support the existence of a bilingual advantage and also indicate that different patterns of bilingual language use modulate the nature and extent of a cognitive control advantage in multilingual populations.