​PREMATURITY, SOUND ENVIRONMENT, AND MATURATION OF THE LANGUAGE NETWORK

Fetuses are able to perceive sounds from around 30 weeks of gestation. This early auditory sensitivity enables full-term newborns to recognize their mother's voice, their native language, and certain melodies heard in utero. These abilities rely on networks located in the superior temporal regions, particularly within the STS, a key cortical region for language processing and voice recognition. This area is especially vulnerable in cases of preterm birth. Microstructural alterations in these temporal regions in preterm infants have been associated with later language difficulties. Furthermore, the early extra-uterine environment, very different from the fetal acoustic environment, may also influence the maturation of these neural networks.

Analysis of MRI data from the developing Human Connectome Project (dHCP), acquired at term-equivalent age in infants born at different gestational ages, revealed a linear relationship between gestational duration and functional connectivity in the right superior temporal region, as well as with STS depth. The authors therefore hypothesized that the reduced STS depth associated with prematurity could result from diminished exposure to structured auditory stimulation during a critical period of language network development.

MUSIC AS A STRUCTURING INFLUENCE ON THE LANGUAGE NETWORK

To test this hypothesis, the researchers examined the direct impact of auditory environment on STS morphology in preterm newborns exposed to contrasting sound conditions. Using the BrainVISA algorithm, they analyzed two published imaging datasets from a controlled study comparing two distinct auditory environments: an enriched environment featuring structured music adapted to infants' sleep-wake rhythms; a calm environment achieved by placing preterm infants in individual rooms to reduce ambient noise. The analyses indicate that exposure to music mitigates the effect of prematurity on STS depth, whereas a silent environment accentuates it.

IMPLICATIONS FOR EARLY BRAIN DEVELOPMENT

These findings suggest that early auditory experience, both in utero and ex utero, shapes the development of temporal brain regions at a macroscopic level. They underscore the importance of better understanding environmental influences in order to optimize postnatal conditions and support harmonious development of auditory and language networks.

Contact : Ghislaine Dehaene-Lambertz (ghislaine.dehaene-lambertz@cea.fr)​

Thumbnail: 3D representation of STS in a full-term newborn © Mancuso et al., Brain Struct Func, 2025