Young children are exceptionally good at acquiring a language compared to adults. New research results now indicate that the foundation for this is laid in the womb. This means that babies get used to the sounds of their native language before they are born. As newborns, their brains become particularly active after hearing familiar language. This suggests that prenatal experience facilitates later learning processes in language acquisition.
Babies begin to hear sounds outside the womb between the 24th and 28th weeks of pregnancy. Previous studies have shown that newborns prefer their mother's voice to other female voices and recognize music they heard before they were born. Familiarity effects are also evident in language. Since the mother's stomach muffles all sounds, no specific words reach the unborn child, but the baby can already grasp the melody and rhythm of speech.
Measurement in newborns
A team led by Benedetta Mariani from the University of Padua in Italy has now examined the extent to which this prenatal experience affects the neural processes involved in language acquisition. To do this, they measured the brain waves of 33 newborns in a Paris university hospital before, during and after they heard sentences in different languages. All children were between one and five days old at the time of the examination and had heard their mother's French language before they were born.
As a stimulus, Mariani and her team played excerpts from the fairy tale “Goldilocks and the Three Bears” in French, English and Spanish in different orders for seven minutes each to the newborns. The babies lay quietly in their cribs and mostly slept while an EEG cap recorded their brain waves. The data from this measurement provided the basis for several studies, each focusing on different aspects.
Language affects brain waves
“For the current study, we were not interested in how the newborn brain processes different languages while listening,” explain Mariani and her team. “Rather, we wanted to know whether listening to speech causes lasting changes in neuronal dynamics that support learning and memory.” Therefore, the researchers compared the brain waves before exposure with those immediately after. “This allowed us to investigate two questions,” says the team: “Firstly, whether the brain generally changes plastically after hearing language, and secondly, to what extent it plays a role whether the child has already learned the relevant language from his or her own time in the womb.”
And indeed: After listening, newborns who had last heard the sentences in French showed significantly increased theta waves in the EEG. These brain wave waves in the frequency range of four to eight hertz are associated with the processing of linguistic syllables, a characteristic of language that the babies were able to experience in the womb. However, this effect was not significant for babies who had last heard English or Spanish in the experiment.
Helpful, but not essential
From the research team's perspective, this suggests that the language that newborns are familiar with from the womb activates their brains more than other languages. “Taken together, these results provide the most convincing evidence to date that language experiences shape the functional organization of the child's brain before birth,” write Mariani and her team.
Accordingly, experiences in the womb lay the foundation for further language development. However, the author team points out that while this influence is helpful, it is not essential. “Even children who have no prenatal experience with a language are able to learn it,” say the researchers. “This can be seen, for example, in children of immigrants, in international adoptees and in babies born deaf after cochlear implantation.”
Source: Benedetta Mariani (University of Padua, Italy) et al., Science Advances, doi: 10.1126/sciadv.adj3524