Evoked and oscillatory EEG activity differentiates language discrimination in young monolingual and bilingual infants

Nácar García, Loreto, 1988-; Guerrero-Mosquera, Carlos; Colomer, Marc; Sebastián Gallés, Núria

doi:http://dx.doi.org/10.1038/s41598-018-20824-0

Evoked and oscillatory EEG activity differentiates language discrimination in young monolingual and bilingual infants

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Nacar Garcia L; Guerrero-Mosquera C; Colomer M; Sebastian-Galles N. Evoked and oscillatory EEG activity differentiates language discrimination in young monolingual and bilingual infants. Sci Rep. 2018;8:2770. DOI:10.1038/s41598-018-20824-0

Abstract

Language discrimination is one of the core diferences between bilingual and monolingual language acquisition. Here, we investigate the earliest brain specialization induced by it. Following previous research, we hypothesize that bilingual native language discrimination is a complex process involving specifc processing of the prosodic properties of the speech signal. We recorded the brain activity of monolingual and bilingual 4.5-month-old infants using EEG, while listening to their native/dominant language and two foreign languages. We defned two diferent windows of analysis to separate discrimination and identifcation efects. In the early window of analysis (150–280ms) we measured the P200 component, and in the later window of analysis we measured Theta (400–1800ms) and Gamma (300–2800ms) oscillations. The results point in the direction of diferent language discrimination strategies for bilingual and monolingual infants. While only monolingual infants show early discrimination of their native language based on familiarity, bilinguals perform a later processing which is compatible with an increase in attention to the speech signal. This is the earliest evidence found for brain specialization induced by bilingualism.