Molnar, M. 1 , Quiñones, I. 1 , Baart, M. 1 , Caballero-Gaudes, C. 1 , Peña, M. 2 & Carreiras, M. 1, 3, 4
1 Basque Center on Cognition, Brain, and Language (BCBL). Donostia, Spain.
2 Catholic University of Chile. Santiago, Chile.
3 IKERBASQUE. Basque Foundation for Science, Bilbao, Spain.
4 University of the Basque Country, UPV/EHU. Donostia, Spain.
By 4 months of age, both monolingual and bilingual infants learn a great amount of information about their native language(s). Behavioral experiments have suggested that even though bilingual infants recognize both of their inputs as familiar and are able to discriminate them already at birth, they attend to their native languages differently as compared to their monolingual peers by 4 months of age. It is unclear why young bilingual and monolingual infants exhibit dissimilar behaviors when attending to their native languages. To assess weather exposure to two vs. one language from birth alters the neural mechanisms of native speech processing, we used near-infrared spectroscopy for recording brain activation during the presentation of native speech, native backward speech, and silence in 4-month-old Basque-Spanish monolingual and bilingual infants. Monolingual infants demonstrated clear left-lateralized responses to native speech in comparison to non-native speech, backward stimuli, or silence. Bilingual infants, however, exhibited no left-lateralized processing in either of their native languages, but demonstrated different processing of Basque and Spanish as compared to the baseline conditions. The development of neural specialization for native speech processing, therefore, appears to follow different patterns in young monolingual and bilingual infants.