First Sounds, Second Language: How Word Onsets Spark Language Co-activation in 3-Year-Old Bilinguals.

Adult and young bilinguals co-activate their languages in different degrees, even in entirely monolingual tasks. However, many studies use translation pairs with high phonological overlap (e.g., the English-GERMAN: 'milk'-'MILCH') making it difficult to discern the origin of the co-activation. This study examined language co-activation in Catalan-Spanish bilingual toddlers using words with minimal phonological overlap across translations. Three-year-olds participated in a visual word paradigm, searching for an absent target (e.g., 'apple' in Catalan: 'poma', Spanish: 'MANZANA') among images with labels that shared the initial phoneme across languages or were unrelated. The design included three types of images: (a) Catalan-to-Spanish phonologically related images (e.g., Spanish 'PATO' for 'duck'), (b) Spanish-to-Catalan phonologically related (e.g., Catalan 'mitjó' for 'sock'), and (c) unrelated items (e.g., 'brush', 'sandwich'). If bilingual toddlers co-activate languages, they should look more at related than unrelated images due to shared phonological onsets. The results supported the hypotheses and provided solid evidence that young bilinguals co-activate phonologically related words in their familiar languages.