Cortical processing of Mandarin lexical tone in children with different language backgrounds

Abstract

Bilingual experience modulates cognitive skills, particularly executive control. However, it is not clear if such modulation can be observed in automatic speech processing. Furthermore, it is unknown if bi-dialectal experience will enhance speech processing. This study aims to investigate whether and how early bilingual experience influences cortical sensitivity for automatic cortical processing of speech, specifically in the context of tonal and non-tonal languages. A passive listening oddball paradigm with two lexical tone contrasts were used and event-related potentials were recorded. An easy contrast (tone 1 versus tone 3) and a hard contrast (tone 2 versus tone 3) were used as the stimuli. Children between 5 and 10 years of age were tested. Preliminary results indicate that monolingual mainstream English, African-American English, and bilingual Mandarin-English learners all showed similar brain responses to the easy lexical tone contrast. However, there was an age effect across language groups. Such results suggest that biological factors such as age are stronger predictors of brain responses to lexical tone contrasts comparing to the factor of language background.