TY - JOUR
T1 - Optical brain imaging reveals general auditory and language-specific processing in early infant development
AU - Minagawa-Kawai, Yasuyo
AU - Van Der Lely, Heather
AU - Ramus, Franck
AU - Sato, Yutaka
AU - Mazuka, Reiko
AU - Dupoux, Emmanuel
N1 - Funding Information:
European Union’s sixth-framework program (neuronal origins of language and communication: NEUROCOM (Project no. 012738); Grant-in-Aid for Scientific Research (A) (Project no. 21682002); Wellcome Trust (063713 to H.L.).
PY - 2011/2
Y1 - 2011/2
N2 - This study uses near-infrared spectroscopy in young infants in order to elucidate the nature of functional cerebral processing for speech. Previous imaging studies of infants' speech perception revealed left-lateralized responses to native language. However, it is unclear if these activations were due to language per se rather than to some low-level acoustic correlate of spoken language. Here we compare native (L1) and non-native (L2) languages with 3 different nonspeech conditions including emotional voices, monkey calls, and phase scrambled sounds that provide more stringent controls. Hemodynamic responses to these stimuli were measured in the temporal areas of Japanese 4 month-olds. The results show clear left-lateralized responses to speech, prominently to L1, as opposed to various activation patterns in the nonspeech conditions. Furthermore, implementing a new analysis method designed for infants, we discovered a slower hemodynamic time course in awake infants. Our results are largely explained by signal-driven auditory processing. However, stronger activations to L1 than to L2 indicate a language-specific neural factor that modulates these responses. This study is the first to discover a significantly higher sensitivity to L1 in 4 month-olds and reveals a neural precursor of the functional specialization for the higher cognitive network.
AB - This study uses near-infrared spectroscopy in young infants in order to elucidate the nature of functional cerebral processing for speech. Previous imaging studies of infants' speech perception revealed left-lateralized responses to native language. However, it is unclear if these activations were due to language per se rather than to some low-level acoustic correlate of spoken language. Here we compare native (L1) and non-native (L2) languages with 3 different nonspeech conditions including emotional voices, monkey calls, and phase scrambled sounds that provide more stringent controls. Hemodynamic responses to these stimuli were measured in the temporal areas of Japanese 4 month-olds. The results show clear left-lateralized responses to speech, prominently to L1, as opposed to various activation patterns in the nonspeech conditions. Furthermore, implementing a new analysis method designed for infants, we discovered a slower hemodynamic time course in awake infants. Our results are largely explained by signal-driven auditory processing. However, stronger activations to L1 than to L2 indicate a language-specific neural factor that modulates these responses. This study is the first to discover a significantly higher sensitivity to L1 in 4 month-olds and reveals a neural precursor of the functional specialization for the higher cognitive network.
KW - NIRS
KW - emotion
KW - infant
KW - laterality
KW - speech perception
UR - http://www.scopus.com/inward/record.url?scp=78651474099&partnerID=8YFLogxK
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U2 - 10.1093/cercor/bhq082
DO - 10.1093/cercor/bhq082
M3 - Article
C2 - 20497946
AN - SCOPUS:78651474099
SN - 1047-3211
VL - 21
SP - 254
EP - 261
JO - Cerebral Cortex
JF - Cerebral Cortex
IS - 2
ER -