title: Impact of second-language experience in infancy: brain measures of first- and second-language speech perception.
abstract: Language experience 'narrows' speech perception by the end of infants' first year, reducing discrimination of non-native phoneme contrasts while improving native-contrast discrimination. Previous research showed that declines in non-native discrimination were reversed by second-language experience provided at 9-10 months, but it is not known whether second-language experience affects first-language speech sound processing. Using event-related potentials (ERPs), we examined learning-related changes in brain activity to Spanish and English phoneme contrasts in monolingual English-learning infants pre- and post-exposure to Spanish from 9.5-10.5 months of age. Infants showed a significant discriminatory ERP response to the Spanish contrast at 11 months (post-exposure), but not at 9 months (pre-exposure). The English contrast elicited an earlier discriminatory response at 11 months than at 9 months, suggesting improvement in native-language processing. The results show that infants rapidly encode new phonetic information, and that improvement in native speech processing can occur during second-language learning in infancy.
authors.affiliation: Institute for Learning & Brain Sciences, University of Washington, Seattle, WA 98195-7988, USA. btconboy@gmail.com
authors.forename: Barbara T
authors.initials: BT
authors.lastname: Conboy
authors.forename: Patricia K
authors.initials: PK
authors.lastname: Kuhl
mesh_terms: D000161:Acoustic Stimulation; D001921:Brain / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D007804:Language Development; D007858:Learning; D008297:Male; D019303:Multilingualism; D010700:Phonetics; D013067:Speech Perception / Q000502:physiology*