Early childhood is a time of rapid cognitive, linguistic, social, emotional and motor development growth, with neural connections forming at a pace of 700 per second! It’s previously been discovered that the brain’s capacity for making connections for language peaks at 9 months, but new research shows that even more is going on prenatally than previously thought.
By looking at international adoptees — babies who were adopted soon after birth and who grow up hearing a different language than what they heard in the womb — researchers can see how what babies hear before and soon after birth affects how they perceive sounds, giving new meaning to the idea of a “birth language.”
Researchers have previously found that newborns can recognize the voices they’ve been hearing for the last trimester in the womb, especially the sounds that come from their mothers, and prefer those voices to the voices of strangers. They also prefer other languages with similar rhythms, rather than languages with very different rhythms. However, researchers used to think that babies didn’t actually learn phonemes — the smallest units of sound that make up words and language, that distinguish one word from another, as in “bag” and “tag” — until the second six months of life.
But new research, including the recent adoptee study, is challenging that notion.
In the latest study, published in January in Royal Society Open Science, Jiyoun Choi, a doctoral student at the Max Planck Institute for Psycholinguistics in the Netherlands, and her colleagues looked at Dutch-speaking adults, some of whom had been adopted from Korea, but none of whom spoke Korean. The researchers found that people born in Korea and adopted as babies or toddlers by Dutch families were able to learn to make Korean sounds significantly better than the Dutch-speaking controls who had been born into Dutch families.
It was especially interesting that this effect held not only for those who had been adopted after the age of 17 months, when they would have been saying some words, but also for those adopted at under 6 months.
In other words, the language heard before birth and in the first months of life had affected both sound perception and sound production, even though the change of language environment happened before the children started making those sounds themselves.
“The conclusion has always been under 6 months, they have no phonology, they have no abstract knowledge about language,” said Anne Cutler, a psycholinguist who is a professor at the Marcs Institute for Brain, Behaviour and Development at Western Sydney University, in Australia. “This shows that even very early in life, babies’ brains are able to distinguish patterns of sound, and apply those rules years later to the task of learning how to produce sounds that have not been part of their daily speech.”
The research emphasizes how important it is to talk, read, and sing to babies. Adults can help infant brain development along naturally with the familiar rhythms of parent-child interactions, back and forth, talking and singing and reading aloud.
“Talk to your baby,” Dr. Cutler said. “Your baby is picking up useful knowledge about language even though they’re not actually learning words. It’s something they really love, the social interaction of you talking with them, but they’re still storing up useful knowledge whenever they hear speech.”