Lost languages leave traces on the brain

Our brains start soaking in details from the languages around us from the moment we can hear them. One of the first things infants learn of their native languages is the system of consonants and vowels, as well as other speech sound characteristics, like pitch. In the first year of life, a baby’s ear tunes in to the particular set of sounds being spoken in its environment, and the brain starts developing the ability to tell subtle differences among them—a foundation that will make a difference in meaning down the line, allowing the child to learn words and grammar.

But what happens if that child gets shifted into a different culture after laying the foundations of its first native language? Does it forget everything about that first language, or are there some remnants that remain buried in the brain?

According to a recent PNAS paper, the effects of very early language learning are permanently etched into the brain, even if input from that language stops and it’s replaced by another language. To identify this lasting influence, the researchers used functional magnetic resonance imaging (fMRI) scans on children who had been adopted to see what neural patterns could be identified years after adoption.