Is there cross-language modulation when bilinguals process number words?

This study explores the possibility of cross-language activation when bilinguals process number words in their first language (Italian) and their second language (German). Italian monolinguals (Experiment 1), German monolinguals (Experiment 2), and Italian/German bilinguals (Experiment 3) were required to decide the larger of two number words while the unit–decade compatibility effect was examined. For compatible trials the decade and unit comparisons lead to the same response (e.g., 24–67), whereas for incompatible trials the decade and unit comparisons lead to different responses (e.g., 27–64). The regular unit–decade compatibility effect was significant when bilinguals and monolinguals performed the comparison in German. However, this effect was not found when bilinguals and monolinguals performed the task in Italian. In addition, the decade distance played a major role when bilinguals processed in their first language, whereas the unit distance was more important when they worked in their second language. These results indicate that the processing of number words in one language is not modulated by the way bilinguals process number words in their alternative language.