Neural measures of vowel discrimination in Spanish-English bilinguals and American English monolinguals

Aims: Understanding the factors influencing language processing in bilinguals compared with monolinguals is important considering the growing population of Spanish-English bilinguals in the United States. We explored non-native phoneme perception and automaticity of speech processing in American-English monolinguals and Spanish-English bilinguals (Mexican heritage Hispanic) using a neurophysiological signature known as the mismatch negativity (MMN). Design: We used non-native speech stimuli to both groups with differing vowel length contrast in an oddball paradigm design. Data and Analysis: EEG data were recorded using a research-grade EEG amplifier (V-Amp, Brain Products GmbH) with 16 and 32 active Ag/AgCl scalp electrodes. A four-way ANOVA was used for the analysis. A total of 30 participants were divided into two groups. Findings: Our findings reveal a distinct potential advantage among bilingual individuals in discriminating stimuli, evident in the slightly larger amplitude observed in MMN responses compared with their monolingual counterparts. Originality: Studies exploring neural activity of bilingual individuals reveal unique patterns of neural connectivity and plasticity, further emphasizing the dynamic nature of the brain. Significance/Implications: This nuanced disparity might have critical implications for health care professionals, including audiologists and speech-language pathologists, as it could provide them with novel insights into the impact of bilingualism on routine diagnostic clinical evaluations of speech perception and communication. The intersection of these fields opens up new avenues for enhancing our comprehension of how language is processed in the brain, particularly in individuals with diverse linguistic experiences.