Project « Neural coding of auditory rhythm during the third trimester of gestation »
Second winning project of the 2023 Annual Prizes of scientific research of “5 senses for kids Foundation” in partnership with the “Societé des Neurosciences”.
The project’s objectives
What is at stake
In recent years, thanks to advances in neonatal resuscitation, the overall survival rate of premature newborns born after 25 sGA has increased (11%, 18% and 13% increase for 25, 26 and 27 sGA, respectively). However, premature infants, and particularly very premature infants, remain exposed to high risks of neurodevelopmental disorders, which is likely to have an impact on the quality of life of the infant and his family, not only during the neonatal period, but throughout throughout his life.
Premature birth not only exposes newborns to potential neurodevelopmental issues of both peripheral and central origin, but it also deprives them of the ever-present rhythmic sounds – maternal and environmental – they would normally experience from outside the womb during the crucial third trimester. This deprivation occurs as they spend a significant portion of this period in the intensive care unit (ICU). The uterus, including those corresponding to the steps, speech and songs that reach the fetus inside the uterus. This change in auditory input has been proposed to contribute to neurodevelopmental disorders, especially since the brain is the site of rapid structural and functional development during the third trimester of gestation. During this period, synaptic connections are refined not only by spontaneous activity, but also and especially by sensory neuronal activity.
The perception of time intervals and rhythmic structure
The perception of time intervals and rhythmic structure is essential to understanding the auditory world. Disruptions to these processes have a negative impact on the development of language and music and, therefore, communication and social interactions. Auditory rhythm coding is particularly important because temporal regularities help predict upcoming sounds in the environment, particularly regarding speech and music. The link between rhythm processing and language processing has sparked much research, and also led to the hypothesis relating to atypical rhythmic abilities as a potential risk factor for the development of language disorders. Yet, we know little about the impact of prematurity on the development of rhythm processing, and whether musical interventions can improve neurodevelopmental deficits. Yet, we know little about the impact of prematurity on the development of rhythm processing, and whether musical interventions can improve neurodevelopmental deficits.
In order to give these children the best possible start, it is essential to understand early deficits, how they affect development in the months following birth, and to seek possible solutions for early action and compensation. We are joining forces in a unique consortium of cognitive neuroscientists, musicians, engineers and clinicians to conduct a structured, controlled longitudinal study on the early neurodevelopment of rhythm perception and the benefits of musical interventions. very early in premature infants.
Project
We use an electrical neuroimaging approach using high-resolution electroencephalography to assess the characteristics of neuronal responses both in preterm infants within 1 week of birth and at term-equivalent ages to assess the development of neural networks . During follow-up sessions, developmental scales and behavioral tasks targeting rhythmic abilities complete our neuroimaging approach, and make it possible to address the cognitive/neuro development, and rhythmic perception of infants, as well as the behavioral and social manifestations of possible deficits in rhythm processing. We aim to reveal the nature and developmental trajectories of rhythm, reduce the difficulties of prematurity and propose effectively targeted interventions to improve the noisy and unstructured auditory environment of neonatal intensive care.
Our approach
Preliminary results
Until December 2023, we recruited 65 premature newborns during the third trimester of gestation and showed that, as in adults, the brains of premature infants train in periodicities in rhythmic auditory sequences at different levels of metric hierarchy. We found that the premature neuronal response does not fully reflect the rhythmic structure of sound sequences, but selectively enhances meter frequencies. This leads to the hypothesis of an active mechanism based on endogenous neuronal oscillations and temporal processing during this early stage of neurodevelopment.
We also showed the evolution of these capacities during the third trimester of gestation. Indeed, these capacities improve with increasing gestational age at birth. Some responses to the rhythmic hierarchy probably occur late in gestation. Indeed, our results show that unlike premature newborns, the perception of the meter (grouping of pulsations) and the selective improvement of the metric response were absent in very premature newborns, suggesting the late development of a representation high-level temporal sequence of the rhythmic sequence at the cortical level.
Project impacts
Now that the ability for rhythmic coding in the premature newborn is established, research is underway to explore the importance of rhythmic sound stimulation during the final weeks of pregnancy. Ultimately, our objective is to determine whether musical interventions can improve the perception of rhythm in these premature babies, thus helping to promote better initial neurodevelopment for these children.
This project is carried out with the direction of Sahar Moghimi, within the Inserm U1105 laboratory, GRAMFC, the University of Picardie Jules Verne, in collaboration with Barbara Tillmann from the University of Burgundy, Laurel Trainor, from the University of Hamilton, Canada, and Fabrice Wallois and Florence Levé of the University of Picardie.
References : Edalati, M., Wallois, F., Safaie, J., Ghostine, G., Kongolo, G., Trainor, L. J., & Moghimi, S. (2023). Rhythm in the premature neonate brain: Very early processing of auditory beat and meter. Journal of Neuroscience, 43(15), 2794-2802.
Recent publications on our studies are available on our website: https://gramfc.u-picardie.fr/premusic-babymusic