By Heather LaRoi, Wisconsin State Journal
By the time a baby is 10 months old, he or she typically will have heard about a million sentences and many millions more words.
Behind the baby’s gurgles and blinks and chuckles and burps, an amazing change is occurring virtually unseen. A little brain is whirring, picking out, processing and sorting out sounds.
It may not be put on display for months to come, but the child is already well on the way to part of its birthright as a human being, with the ability to communicate with richness and nuance.
That transformation has intrigued UW-Madison psychologist Jenny Saffran for more than a decade.
“Language is arguably the hardest thing any of us ever have to learn, ” Saffran said. “Languages are wildly complicated and yet by the time children are 2 or 3, they might be able to produce all these complexities.”
As part of a quest to figure out how this happens, more than 1,200 infant visitors a year stop by the Infant Learning Lab, which Saffran directs, at the Waisman Center. There, infants will sit on a parent’s lap and their responses to various blinking lights and streams of nonsense words will be monitored. The underlying premise is that what ‘s new is interesting to an infant, and what is familiar — or previously learned — is less interesting.
What Saffran’s research has shown is that babies, with remarkable deftness, are able to detect consistent patterns in sounds they hear and to somehow figure out where words begin and end. While completely untaught in infants, this skill is absolutely critical to language building.
“In just a couple of minutes, babies can actually listen to a stream of speech and where we’ve stripped out everything else — things like pitch and rhythm and breathing — babies will actually respond to sounds that go together reliably as words relative to sounds that don’t, ” said Saffran, who has been part of UW-Madison’s psychology department since 1997.
“We don’t think of babies as being statisticians, but our brains are computers and babies’ are no different. By age 7 or 8 months, babies are exquisitely talented at pulling words out of speech and finding those spaces (between words) even when they don’t exist in the physical world. ”
As might be expected, Saffran’s research has propelled her into ongoing nature versus nurture debates. Learning language, Saffran says, is a paramount example of the two forces interacting.
“Nurture matters incredibly in the sense that you have to have experience to learn from, but you also have to come at it with learning abilities that are well-tailored to the task at hand,” Saffran said.
“If you don’t have exposure to the language, you obviously can’t learn it. But if you think about these learning abilities, they have to be part of our genes, they have to be part of our innate capacities. Otherwise, how could 8-month-old babies learn so much in two minutes?”
Saffran’s lab has more than a dozen research projects running involving children’s language learning, from a baby ‘s ability to detect the different rhythms of a foreign language, to the challenges posed by a child who doesn’t hear sounds in the first year.
If Saffran is no longer as surprised by what human brains can do, she can still be amazed.
“The drive to find patterns, the drive to make sense of our environment is really, really, really strong,” she said. “That’s probably part of why we — and many other species — have done so well. With babies it seems particularly adaptive.”
Babies and talk Discovery:
Babies as young as 6 months can discern word units in the stream of conversation around them.
What it means: Babies’ brains have the innate ability to figure out the basic building blocks of language.
Why it matters: An understanding of how typically developing learners acquire language is necessary before it ‘s possible to understand how things can go wrong or how to remediate that, says UW-Madison psychologist Jenny Saffran.
Down the road, a better understanding of how the brain acquires language may also have implications for helping those with language problems due to stroke or degenerative brain diseases.