Infant language learning

An infant's brain activity is monitored for signs of learning in the uterus. Prenatal experiences shape infants' brains, according to a study in Proceedings of the National Academy of Sciences. (Veikko Somerpuro / University of Helsinki, / August 26, 2013)

Watch your mouth around your unborn child – he or she could be listening in. Babies can pick up language skills while they’re still in the womb, Finnish researchers say.

Fetuses exposed to fake words after week 29 in utero were able to distinguish them after being born, according to new research in the Proceedings of the National Academy of Sciences.

"Prenatal experiences have a remarkable influence on the brain's auditory discrimination accuracy, which may support, for example, language acquisition during infancy," the authors wrote in their study. 

As revealed by the allure of the so-called Mozart Effect – the idea that exposing the fetus to classical music earns kids extra IQ points in spatial reasoning down the line – parents are constantly looking for ways to give their children an intelligence advantage.

That’s even if the research their parenting tactics are based on is too narrow to draw such broad conclusions or remains under question (the Mozart Effect was deemed "crap," for example, by one scientist.)

Nonetheless, scientists have discovered plenty of evidence that what's heard in utero can make a lasting impression. Fetuses respond differently to native and nonnative vowels, and newborns cry with their native language prosody (a combination of rhythm, stress and intonation). Researchers led by Eino Partanen at the University of Helsinki wanted to see what other language cues a fetus might pick up in the womb.

For the experiment, Finnish mothers were asked to play a CD with a pair of four-minute tracks that held music punctuated by a fake word: tatata. On occasion, they changed up the vowel – tatota – and in other instances they switched the pitch – tatata, when the middle syllable could be 8% higher or lower, or 15% higher or lower. The false word and its variants featured hundreds of times as the tracks played, and the mothers were asked to play the CD five to seven times per week.

Then, after several weeks of exposure to the fake word, the researchers had to determine whether all this in-utero training had somehow stuck.

The researchers were relying on a phenomenon called mismatch response: a flash of neural activity when the brain picks up on something off, something not quite right – such as when the word tatata is suddenly tatota. If that flash goes off, it means that something doesn’t make sense compared to what the brain has already learned.

The scientists figured that if the flash went off the first time the infant babies heard the modified words (tatota or tatata) after being born, it would mean that they’d been paying attention while in the womb.

They tested the mismatch response once the babies were born by attaching electrodes and studying their brain activity.

Sure enough, the newborns that had been trained in the womb had a response roughly four times stronger to the pitch change (tatata versus tatata) than untrained newborns. (Both trained and untrained babies picked up the tatata versus tatota vowel distinction.)

The findings could mean it’s possible to give babies a little language leg-up before they ever say a word -- particularly the children who may need it most.

"It might be possible to support early auditory development and potentially compensate for difficulties of genetic nature, such as language impairment or dyslexia," the authors wrote.

But, the scientists point out, it could mean that babies are also vulnerable to harmful acoustic effects – "abnormal, unstructured, and novel sound stimulation" – an idea that will also require further study. Until then, perhaps it’s best not to hang around any noisy construction sites while pregnant.