The importance of the maternal figure for infants is undisputed today, but we may not have realized the extent to which this was the case. Having babies born prematurely listen to recordings of their mother’s voice would have a concrete effect on their development and not the least: it would accelerate the maturation of their brain. This is what the latest clinical trial conducted by researchers at Weill Cornell Medicine College in New York reveals, reports New Scientist.
To fully understand the significance of this discovery, we must return to the origins of the human brain. If the establishment of brain structures takes place during the first months of pregnancy, the development of the brain and the establishment of nerve connections take place during the third trimester. Premature birth thus weakens the process, notably altering the brain structures linked to language.
For more than a decade, scientists have shown that the mother’s voice – just like her heartbeat – stimulates the development of pathways associated with hearing and language skills in the fetus. For a premature baby, being in an incubator deprives him of these familiar landmarks, replaced by the beeps of machines and the voices of medical staff. The New York team wanted to know if hearing recordings of the mother’s voice could compensate for this absence. And the results are rather conclusive.
The study was carried out on a sample of forty-six premature babies, born after 24 to 31 weeks of gestation and hospitalized in neonatal intensive care. Their mothers recorded themselves reading Paddington Bear. The recording, lasting around ten minutes, was broadcast to half of the infants twice an hour, between 10 p.m. and 6 a.m. Result: these children were exposed to the mother’s voice approximately three hours more per day than the control group.
Stronger neural connections
Once the babies reached term, MRI scans made it possible to analyze the organization of their neural networks. In those who had heard their mothers during the night, the connections were not only stronger, but also better structured around the left arcuate fasciculus, a key language processing area. This maturation is believed to be due to increased myelination, i.e. the formation of fatty sheaths insulating nerve fibers and accelerating the propagation of brain signals.
“Myelination is a pillar of healthy brain development, particularly in areas related to communication and learning»explains Katherine Travis, director of the Language Development and Recovery Laboratory at the Institute.
But would babies only react to the voice of their parent? The study does not specify this, although we can assume that it is the continued exposure to their mother’s voice in the womb which would explain this postnatal preference. The researcher recognizes, however, that other voices – such as that of the father or a regular caregiver – could produce similar results.
David Edwards, director of the Institute of Women and Children’s Health at King’s College London, is less enthusiastic. “The sample is very small. Other control groups, other sources of speech and other forms of auditory stimulation would be needed.» The American team is also aware of this and plans to confirm these results in large-scale trials. The future will also make it possible to measure whether this early exposure to the mother’s voice translates, as toddlers grow, into better language skills.
