Published online by Cambridge University Press: 13 September 2016
Research on American-English (AE) vowel perception by Spanish–English bilinguals has focused on the vowels /i/-/ɪ/ (e.g., in sheep/ship). Other AE vowel contrasts may present perceptual challenges for this population, especially those requiring both spectral and durational discrimination. We used Event-Related Potentials (ERPs), MMN (Mismatch Negativity) and P300, to index discrimination of AE vowels /ɑ/-/ʌ/ by sequential adult Spanish–English bilingual listeners compared to AE monolinguals. Listening tasks were non-attended and attended, and vowels were presented with natural and neutralized durations. Regardless of vowel duration, bilingual listeners showed no MMN to unattended sounds, and P300 responses were elicited to /ɑ/ but not /ʌ/ in the attended condition. Monolingual listeners showed pre-attentive discrimination (MMN) for /ɑ/ only; while both vowels elicited P300 responses when attended. Findings suggest that Spanish–English bilinguals recruit attentional and cognitive resources enabling native-like use of both spectral and durational cues to discriminate between AE vowels /ɑ/ and /ʌ/.
The research reported here was partially funded by a grant to the first author (Vice President's Student Research in Diversity Grant from Teachers College, Columbia University), and by P20 GM109023 (Boys Town National Research Hospital). It formed part of the first author's doctoral dissertation work. The authors thank the following people for assistance during the study: Dayna Moya, Guannan Shen, Lisa Levinson, Heather Green, Felicidad García and Trey Avery in the Neurocognition of Language Lab, Teachers College, Columbia University. We are deeply thankful to Kanae Nishi, Michael Gorga, Rachel Scheperle, Ben Kirby, Erika Levy and Laura Sánchez for their comments and suggestions on the manuscript and on earlier versions of this work.