Dear professors and colleagues,,
The seminar on 3/12 will be held at NCU, and with Ying-Ying Cheng as the invited speaker. Please refer to the following details for the seminar:
Speaker:
Ph.D. Ying-Ying Cheng
Topic:
Development of Mismatch Responses to Mandarin Lexical Tones, Vowels in early infancy
Venue:
Science Building #4, S4-209, NCU (中央大學科四館209室)
Date & Time:
2019/03/12, 14:00~16:00
(There will no post-seminar meeting after the talk.)
Title: Development of Mismatch Responses to Mandarin Lexical Tones, Vowels in early infancy
Ying-Ying Cheng
The ability of phonetic discrimination in early infancy has been suggested to be one of the foundations of language and reading acquisition. Behavioral studies have shown that children acquire lexical tones first, then the vowels and final consonants, and the initial consonants at last. According to the phonological saliency hypothesis, the discrepancy of developmental trajectories suggested that phonological units with higher phonological saliency should be more accessible for children. This hypothesis requires further evidence, especially neurophysiological ones at a younger age. In this talk, I will present the study examining exploring the development of speech perception in Mandarin infants from birth to 24 months by measuring mismatch responses. Mismatch negativity (MMN), which is an ERP component index automatic change detection, has bee widely used for investigating people unable to following task commands. Moreover, positive mismatch response (P-MMR) has also been observed in infancy, especially at a younger age and for more difficult contrast. P-MMR is suggested to index less mature brain response to incoming changes. This study examined how age, phonological saliency and deviant size affect MMRs in infancy. MMRs to lexical tones, vowels, and initial consonants were measured every 6 months from birth to 24 months using multi-deviant oddball paradigm. The results showed P-MMR to the three phonological units at newborns. For lexical tone, MMN to large deviant (T1/ T3) first presented at 6 months and sustained at older ages, while small deviant (T2/T3) elicited P-MMR at 6 to 18 months. For vowels, large deviant (du/da) elicited MMN at 6, 18 and 24 months. MMN to small vowel deviant (di/da) first evidenced at 18 months and sustained at 24 months. As for initial consonant, P-MMR to large deviant (ga/ba) was sustained until the first presence of MMN at 24-month-old. Small initial consonant deviant (da/ba) elicited P-MMR in all age groups. These findings showed MMRs transit from P-MMR to MMN with age increasing. The developmental trajectory of the transition form P-MMR to MMN supported the phonological saliency hypothesis, while the timetable of transition also depends on the discriminability of a contrast. These findings suggested that the transition from P-MMR to MMN could serve as a neurophysiological index to evaluate maturation of speech perception.