Brain potentials to native phoneme discrimination reveal the origin of individual differences in learning the sounds of a second language.
Human beings differ in their ability to master the sounds of their second language (L2). Phonetic training studies have proposed that differences in phonetic learning stem from differences in psychoacoustic abilities rather than speech-specific capabilities. We aimed at finding the origin of individual differences in L2 phonetic acquisition in natural learning contexts. We consider two alternative explanations: a general psychoacoustic origin vs. a speech-specific one. For this purpose, event-related potentials (ERPs) were recorded from two groups of early, proficient Spanish-Catalan bilinguals who differed in their mastery of the Catalan (L2) phonetic contrast /e-epsilon/. Brain activity in response to acoustic change detection was recorded in three different conditions involving tones of different length (duration condition), frequency (frequency condition), and presentation order (pattern condition). In addition, neural correlates of speech change detection were also assessed for both native (/o/-/e/) and nonnative (/o/-/ö/) phonetic contrasts (speech condition). Participants' discrimination accuracy, reflected electrically as a mismatch negativity (MMN), was similar between the two groups of participants in the three acoustic conditions. Conversely, the MMN was reduced in poor perceivers (PP) when they were presented with speech sounds. Therefore, our results support a speech-specific origin of individual variability in L2 phonetic mastery.
Díaz
Begoña
B
Grup de Recerca Neurociència Cognitiva, Parc Científic UB and Hospital Sant Joan de Déu (Edifici Docent), Santa Rosa 39-57, Esplugues, Barcelona 08950, Spain.
Baus
Cristina
C
Escera
Carles
C
Costa
Albert
A
Sebastián-Gallés
Núria
N
D001921:Brain / Q000502:physiology*; D006801:Humans; D007802:Language; D010700:Phonetics; D013067:Speech Perception / Q000502:physiology*