Cortical plasticity for speech processing in English & Mandarin-speaking adolescents: The effect of transcranial direct current stimulation

Abstract

Language experience and brain maturation both shape speech processing at the cortical level. To examine whether transcranial direction stimulation (tDCS) shows any effect on automaticity of neural speech processing in relation to language experience in adolescents, we recorded event-related potentials (ERP) to a speech contrast both before and after administering tDCS. The participants were adolescents (14–19 years old) from monolingual English-speaking households and bilingual English-Mandarin speaking households. We used a passive listening oddball paradigm and recorded ERP responses before and after 10 minutes of tDCS. The mismatch negativity (MMN) and late negativities (LN) were examined. Both groups showed clear neural discrimination. We observed language group differences in the amplitudes of MMN and stimulus condition differences in the amplitudes of LN. The preliminary analyses of ERP responses before and after tDCS suggest that one short session of tDCS does not influence neural discrimination of speech in typically-developing adolescents.