title: Developmental changes in brain activation involved in the production of novel speech sounds in children.
abstract: Older children are more successful at producing unfamiliar, non-native speech sounds than younger children during the initial stages of learning. To reveal the neuronal underpinning of the age-related increase in the accuracy of non-native speech production, we examined the developmental changes in activation involved in the production of novel speech sounds using functional magnetic resonance imaging. Healthy right-handed children (aged 6-18 years) were scanned while performing an overt repetition task and a perceptual task involving aurally presented non-native and native syllables. Productions of non-native speech sounds were recorded and evaluated by native speakers. The mouth regions in the bilateral primary sensorimotor areas were activated more significantly during the repetition task relative to the perceptual task. The hemodynamic response in the left inferior frontal gyrus pars opercularis (IFG pOp) specific to non-native speech sound production (defined by prior hypothesis) increased with age. Additionally, the accuracy of non-native speech sound production increased with age. These results provide the first evidence of developmental changes in the neural processes underlying the production of novel speech sounds. Our data further suggest that the recruitment of the left IFG pOp during the production of novel speech sounds was possibly enhanced due to the maturation of the neuronal circuits needed for speech motor planning. This, in turn, would lead to improvement in the ability to immediately imitate non-native speech.
authors.affiliation: Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, 980-8575, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hashizume
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Taki
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sassa
authors.forename: Benjamin
authors.initials: B
authors.lastname: Thyreau
authors.forename: Michiko
authors.initials: M
authors.lastname: Asano
authors.forename: Kohei
authors.initials: K
authors.lastname: Asano
authors.forename: Hikaru
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Rui
authors.initials: R
authors.lastname: Nouchi
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kotozaki
authors.forename: Hyeonjeong
authors.initials: H
authors.lastname: Jeong
authors.forename: Motoaki
authors.initials: M
authors.lastname: Sugiura
authors.forename: Ryuta
authors.initials: R
authors.lastname: Kawashima
mesh_terms: D000293:Adolescent; D001921:Brain / Q000254:growth & development* / Q000502:physiology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology; D002648:Child; D004192:Discrimination, Psychological / Q000502:physiology; D005260:Female; D006801:Humans; D007564:Japan; D007804:Language Development; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D010700:Phonetics; D013060:Speech / Q000502:physiology*
keywords: childhood; cognitive neuroscience; development; fMRI; second language; speech production