How do infants raised in bilingual homes learn words and how are the words represented in the infant bilingual mind? Answers to these questions are heavily influenced by the similarity of the languages involved. For instance, Dutch/English are close, while Chinese/English are distant. At the word level, language similarity is reflected in the percentage of 'cognate' words that two languages share. Cognates are word translations with the same etymological origin and sound similar (father/vader in English/Dutch). Naming studies with adults have shown the importance of cognates in bilinguals. Adult bilinguals can name pictures faster when they correspond to cognates (father/vader) than pictures corresponding to non- cognates (bicycle/fiets). A critical property of adult bilingualism is that of non-selective access to words in both languages. Bilinguals activate all potential word candidates from either language consistent with what they hear or want to say, even in fully monolingual situations. This points to important interactions between the two languages in the bilingual mind. Such interactions are likely even more important in the case of infants raised bilingually. Such infants often know only one word in one of their languages to refer to a concept. In this situation, cross-language lexical similarity may facilitate word recognition, but it may hinder the establishment of language-specific lexicons. We propose to conduct a series of experimental studies to uncover the structure of the mental
lexicon in bilingual infants, and to construct brain-inspired models to explore theoretical accounts of the structure of their lexicon(s).