Published online by Cambridge University Press: 23 April 2013
Research with monolingual children has shown that early efficiency in real-time word recognition predicts later language and cognitive outcomes. In parallel research with young bilingual children, processing ability and vocabulary size are closely related within each language, although not across the two languages. For children in dual-language environments, one source of variation in patterns of language learning is differences in the degree to which they are exposed to each of their languages. In a longitudinal study of Spanish/English bilingual children observed at 30 and 36 months, we asked whether the relative amount of exposure to Spanish vs. English in daily interactions predicts children's relative efficiency in real-time language processing in each language. Moreover, to what extent does early exposure and speed of lexical comprehension predict later expressive and receptive vocabulary outcomes in Spanish vs. English? Results suggest that processing skill and language experience each promote vocabulary development, but also that experience with a particular language provides opportunities for practice in real-time comprehension in that language, sharpening processing skills that are critical for learning.
We are grateful to the children and parents who participated in this research. Special thanks to the reviewers and editors of this journal for their thoughtful comments and suggestions. Thanks to Adriana Weisleder, Lucía Rodríguez Mata, Ana Luz Portillo, Amber MacMillan, Renate Zangl, Lucia Martinez, Araceli Arroyo, and the staff of the Center for Infant Studies at Stanford University. This work was supported by grants from the National Institutes of Health to Anne Fernald (HD 42235, DC 008838) with a Postdoctoral Research Supplement for Underrepresented Minorities to Nereyda Hurtado and a National Research Service Award (NRSA) to Theres Grüter (F32 DC010129-01).