Development of hemispheric specialization for lexical pitch-accent in Japanese infants.
Abstract
Infants' speech perception abilities change through the first year of life, from broad
sensitivity to a wide range of speech contrasts to becoming more finely attuned to
their native language. What remains unclear, however, is how this perceptual change
relates to brain responses to native language contrasts in terms of the functional
specialization of the left and right hemispheres. Here, to elucidate the developmental
changes in functional lateralization accompanying this perceptual change, we conducted
two experiments on Japanese infants using Japanese lexical pitch-accent, which changes
word meanings with the pitch pattern within words. In the first behavioral experiment,
using visual habituation, we confirmed that infants at both 4 and 10 months have sensitivities
to the lexical pitch-accent pattern change embedded in disyllabic words. In the second
experiment, near-infrared spectroscopy was used to measure cortical hemodynamic responses
in the left and right hemispheres to the same lexical pitch-accent pattern changes
and their pure tone counterparts. We found that brain responses to the pitch change
within words differed between 4- and 10-month-old infants in terms of functional lateralization:
Left hemisphere dominance for the perception of the pitch change embedded in words
was seen only in the 10-month-olds. These results suggest that the perceptual change
in Japanese lexical pitch-accent may be related to a shift in functional lateralization
from bilateral to left hemisphere dominance.
Type
Journal articleSubject
Acoustic StimulationAge Factors
Analysis of Variance
Asian Continental Ancestry Group
Brain Mapping
Cerebral Cortex
Dominance, Cerebral
Female
Hemoglobins
Humans
Infant
Language
Male
Pitch Perception
Reaction Time
Spectroscopy, Near-Infrared
Time Factors
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https://hdl.handle.net/10161/4622Published Version (Please cite this version)
10.1162/jocn.2009.21377Publication Info
Sato, Yutaka; Sogabe, Yuko; & Mazuka, Reiko (2010). Development of hemispheric specialization for lexical pitch-accent in Japanese infants.
J Cogn Neurosci, 22(11). pp. 2503-2513. 10.1162/jocn.2009.21377. Retrieved from https://hdl.handle.net/10161/4622.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Reiko Mazuka
Research Professor in the Department of Psychology and Neuroscience
Language acquisition and psycholinguistics. In
particular, she is interested in the development and
consequences of acquiring very different types of
languages. The research has taken a cross-linguistic
approach between English and Japanese, and her
current research involves the following three areas: (1)
study of sentence comprehension strategies by adult
and child speakers of Japanese and English; (2) cross-
linguistic study of infants' speech perception; and (3)
influence of acquiring

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