Infants begin to be familiarized with sound patterns associated with certain languages while still in the womb. But what happens to those neural pathways when an infant is adopted internationally and is no longer exposed to that first language? New research has found that the unconscious brain still retains the familiarity to that language years later. The paper was published in Proceedings of the National Academy of Sciences, and Lara Pierce of McGill University in Montreal led the research.
The study consisted of 48 girls between the ages of 9 and 17, splitting them into three groups. One group spoke French exclusively; the second group had been adopted from China as babies, but only spoke French and had not continued to be exposed to Chinese; and the third group was fluent in both French and Chinese since birth.
"The infant brain forms representations of language sounds, but we wanted to see whether the brain maintains these representations later in life even if the person is no longer exposed to the language," Pierce said in a press release.
Each group underwent functional MRI, allowing researchers to see which parts of the brain were activated when the participants were exposed to Chinese language sounds. Quite surprisingly, the group that had been adopted showed activation patterns that were very similar to the bilingual group. This shows that even though the adoptee group hadn’t heard Chinese for an average of 12 years, the brain recognized the sound pattern as linguistically relevant. The group that had only been exposed to French since birth did not view those sounds as recognizable in the same way as the other two groups.
Functional MRI scans of the three groups of girls as they are exposed to sounds of the Chinese language. Credit: Montreal Neurological Institute, McGill University
"It astounded us that the brain activation pattern of the adopted Chinese who 'lost' or totally discontinued the language matched the one for those who continued speaking Chinese since birth. The neural representations supporting this pattern could only have been acquired during the first months of life," Pierce continued. "This pattern completely differed from the first group of unilingual French speakers.”
The results suggest that not only is the young brain extremely adept at picking up on the patterns and sounds of languages, but those channels seem to be preserved over many years. The ongoing existence of these neurological pathways raises many more questions with a variety of implications. This pattern recognition could have unconsciously influenced the processing of other information in the brain.
The researchers are also curious if this could have implications for an increased ability to re-learn the language, and if it does, if this could work with other types of information. This could be a way to help develop the brains of infants and prepare them for skills they won’t use for several years.
[Header image credit: Laurent Jégou via Flickr, CC BY-ND 2.0]