Listening with Your Cohort: Do Bilingual Toddlers Co-Activate Cohorts from Both Languages When Hearing Words in One Language Alone?

Bilingual children, like bilingual adults, co-activate both languages during word recognition and production. But what is the extent of this co-activation? In the present study, we asked whether or not bilingual preschool children activate a shared phonological cohort across languages when hearing words only in their L1. We tested German-English children on a cross-modal priming paradigm. To ensure co-activation of languages, children first heard a short code-switch story. Compared to a monolingual control group, bilingual children in Experiment 1 showed only partial sensitivity to the L1 cohort. Bilingual children who did not hear the code-switch story (Experiment 2) showed priming effects identical to the monolinguals in Experiment 1. Results indicate that under single-language contexts, German-English bilingual preschoolers do not activate the non-target language cohort during word recognition but instead restrict cohort activation to the language of input. In contrast, presentation of the non-target language in the code-switch story appears to shift cohort activation and increase L2 activation, suggesting a highly flexible language system that is in tune to the broader linguistic context. We consider mechanisms of bilingual language control that may enable bilingual toddlers to limit cross-language phonological activation.