Competition for selection drives the nature of bilingual language control: Picture naming, but not reading aloud, triggers global inhibition of the dominant language.

The current study tested the hypothesis that bilingual language control mechanisms vary depending on the extent of competition for selection. Forty-eight English-dominant Spanish-English bilinguals switched languages in production of single words, which was elicited with picture naming versus reading aloud in counterbalanced order. Results revealed some key similarities across tasks including: a) significant switch costs, b) larger switch costs in the dominant when compared to the nondominant language (i.e., in English versus in Spanish), and c) only the nondominant language benefitted from repetition. However, switch costs were larger in picture naming than in reading aloud, and only the picture naming task exhibited the strongest signature effect of inhibition of the dominant language in the form of reversed language dominance. These results provide evidence that language control mechanisms adapt to meet varying task demands depending on the nature and extent of competition for selection between languages.