Research
Current
The Nature of Phoneme Representation (Role: Co-PI)
The project asks whether the phoneme representation contains acoustic details. Using the varying-standards oddball paradigm, we present subjects with frequent voiceless stops varying in VOT interspersed with infrequent voiceless stops with a different VOT. An MMN elicited by the within-category deviance would suggest that the brain extracts a phoneme representation containing the acoustic details.
Funded by NSF DDRIG (PI: Arild Hestvik. Co-PI: Chao Han)
Underspecificaiton and Auditory Processing Disorder (Role: Researcher)
§ The project asks whether the auditory processing disorder (APD) affects speech processing at the acoustic level or the phonological level. The acoustic-level processing is indexed by symmetric MMNs elicited in a classical oddball paradigm which presents voicing contrasts in both directions; the phonological-level processing is indexed by asymmetric MMNs elicited in the varying-standards paradigm where one of the two types of standards shows featural underspecificaiton in the phonological level. We tested children with APD using both paradigms and compared their results to those of typically developed children.
§ Funded by NIH COBRE Grant (PI: Kyoko Nagao. Co-PI: Arild Hestvik, and Thierry Morlet) and NIH NIGMS IDeA (PI: Stuart Binder-Macleod)
Previous
Discriminability and **Pr**ototypicality of Vowel Perception (Role: Researcher)
§ This project asks how discriminability and prototypicality modulate the MMN amplitude. In the MMN paradigm, we presented Japanese speakers with English [æ, ɑ] as standards and [ʌ] as deviants. Although the [æ - ʌ] contrast is more discriminable according to the Perceptual Assimilation Model, we found a larger MMN for the [ɑ - ʌ] contrast as [ɑ] is perceived as a more prototypical member of Japanese /a/.
§ Funded by Japan Society for Promotion of Science KAKENHI Grant (PI: Yasuaki Shinohara. Co-PI: Arild Hestvik).
L2 Processing of Filled Gaps (Role: Researcher)
§ The project investigates how L2 learners resolve English filler-gap dependencies using an ERP experiment. We found that although L2 learners’ behavioral performance is comparable to native speakers and is positively correlated with proficiency and working memory, their brain response is qualitatively different from that of native speakers regardless of their proficiency level.
Perceptual Confusion of Mandarin Tones (Role: Researcher)
§ The project investigates the perceptual confusion of Mandarin Tone 3 and Tone 4 in connected speech. In the four-alternative forced-choice task, participants identified syllables extracted from tri-syllabic words recorded in short dialogues. The results showed the same level of perceptibility of T3 and T4. Furthermore, the two tones were better perceived when in a focused context or at the edge of a word, confirming the effect of prosodic structure on tonal perception.