Parents should talk, coo, play with children to stimulate their language skills, researchers suggest
2005-03-21 / Knight Ridder / By Paula Bock

 

How do babies learn to talk?

How to decipher what's syllable? What's smile? What's significant? What's sneeze?

For eons, babies have been routinely cracking the speech code. For almost as long, nobody thought much of that feat, or of infant intellect, except, perhaps, their mothers, who sensed those first words were pure genius, but not appropriate to brag about in the supermarket, and certainly not the basis for revolutionary scientific research.

Then came clever experiments to figure out what babies know and when. Would just-born babies imitate when an adult stuck his tongue out? Yes! Without ever seeing their own faces, newborns come into the world knowing they are like other humans.

Then came other tools to peek into the infant mind: video, audio, computer synchronization, the electroencephalogram (EEG), functional magnetic resonance imaging (FMRI), magnetoencephalography (MEG), a tower of machinery dubbed "the hairdryer from hell." For the first time, scientists could precisely tell what babies watch, how they sort sounds, whether foreign languages resonate, when "critical windows" of learning open and close, what infants understand about other people's actions, likes, dislikes and intentions. We are beginning to understand how we learn to care about each other.

Most startling? Babies are smarter than the rest of us.

Baby-brain research, once the Home-Ec of sciences, is now hot - a topic that trumps biotech and global health at Seattle dinner parties and lands researchers millions in funding, appearances on talk shows, and invitations from both for U.S. Presidents Bill Clinton and George W. Bush to White House conferences on early childhood education.

Another measure of the field's rise: The University of Washington last year devoted prime waterfront real estate to the new Institute for Learning & Brain Sciences. The old brick fisheries building is now home to an interdisciplinary center co-directed by professors Patricia Kuhl and Andrew Meltzoff.

Considered a top lab of its kind, I-LABS collaborates with scientists in Finland, Japan, Mexico and 37 other countries, last year pulling in more than US$4 million in funding, and was also part of a consortium awarded a coveted US$25 million Science of Learning grant from the National Institutes of Health. Hallway bulletin boards flutter with papers published in the prestigious journals Science and Nature, as well as glossy pop magazines featuring wise-eyed babies wearing polka-dot electrode caps.

The questions: What do babies know about language, when do they know it, and what's the best time for them to learn it? Can babies learn from television? Can we know something about who we're going to be by looking at a little baby? "That's as fully important as sending rovers to Mars," Meltzoff says.

Kuhl and Meltzoff, who happen to be married, share a certain glamour that comes with being at the top of their fields in a science ripe for breakthroughs. After the space-age '70s, the software '80s and the biotech '90s, perhaps the science of the millennium belongs to baby brains - and Kuhl and Meltzoff are proud parents.

To them, a baby is a scientific miracle, the best learning machine on the planet, more powerful than the most advanced supercomputer, able to learn languages faster and better than adults, quick to recognize and manipulate the social cues that govern everything from war to animal cookies.

Born with 100 billion neurons, about the same number as stars in the Milky Way, babies suck in new information and statistically analyze it, comparing it with what they've previously heard, seen, tasted and felt, constantly revising their theories of the world and how it works. By 3 years old, babies have about 15,000 synapses per neuron, three times the synapses of adults. That's one of the reasons it's easier to learn foreign languages when you're young. But pruning neural connections at key times, much as gardeners prune roses in late winter, is also critical so the brain isn't overwhelmed with extraneous information and can focus on what's important.

"The brain prepares itself to learn things at a certain time," Kuhl says. "Communication and social relations are early, because in order to maneuver in the world, to survive as a hominid, you had to relate to the other hominids."

Brain researches

In graduate school at the University of Minnesota, she studied which parts of the brain were responsible for language by thinly slicing the gray matter of human cadavers who had suffered aphasia and strokes. Then she applied questions about language and neurobiology to chinchillas and monkeys, demonstrating that they initially decode the sounds of language the same way babies do, by hearing auditory "edges" (similar to the way we see visual edges signaling, say, where a cup ends and the table begins).

Kuhl's findings, published in 1975 in Science, were shocking and unpopular. "We humans think our language is unique," she says. "But evolution arranged it so babies came into the world with no trouble hearing distinctions and sorting out sounds."

Kuhl forged ahead, undeterred by critics or the dearth of other women in acoustics. (As a post-doc in St. Louis, she had to walk down three flights to find a ladies room.) She completed her Ph.D in three speedy years, was promoted to full professor at the UW in five. Along the way, she showed that adults naturally use high-pitched, lilting "mother-ese" to help teach babies language; and that babies are "citizens of the world" when they're 6 months old - able to hear all the sounds of every language - but lose that ability by their first birthday as their brains commit to a native tongue.

Heady stuff, but hard at home. "The life of a scientist is murderous," Kuhl says. Her first marriage of 12 years didn't last. "In high-flying labs, how many hours after midnight? It's an enormous strain."

Meanwhile, on the Jersey shore, Andy Meltzoff spent idyllic childhood summers becoming a champion surfer at his family's beach home. His mother was a reading teacher, his father the chief clinical psychologist at a New York City veterans hospital.

As a Harvard undergrad, Meltzoff was mentored by Jerome Bruner, a developmental psychologist instrumental in founding the Head Start program. Bruner believed developmental psychology could not only answer age-old questions about the mind but also help transform society.

"When I knew Andy, he was a golden boy, Harvard, handsome, smart," plus he made a major scientific discovery at 27, says Alison Gopnik, a professor at the University of California, Berkeley, who met Meltzoff during graduate school at Oxford, when they'd float in a punt on the River Cherwell and he'd talk about his dream of an enormous center where scientists could do developmental, computational and neuroscience research with plenty of money and no bureaucracy.

Meltzoff's discovery, that newborns will stick out their tongues to imitate adults, demonstrated a connection between self and other from the moment of birth.

"We're a role model for babies from the moment they look up at us and begin to sculpt their own activities according to what they see in the culture around them," Meltzoff says. This rocked the foundations of developmental psychology. Piaget, Sigmund Freud and B.F. Skinner had taught that newborns were social isolates with no knowledge of other people when they came into the world.

Not long after Meltzoff moved to Seattle, Gopnik noticed he was taking off in other ways. All of a sudden, in his Spartan bachelor apartment, there were lavender pillows. A potted plant. "Wait a minute," Gopnik says, "I think there's a woman here, and I think she's blonde!

At first, Meltzoff and Kuhl both claim, it was all about science. Something about whether babies connect faces with voices and match lip shapes with vowel sounds. In the experiment, a baby sat in front of two monitors. On one, Pat's face silently mouthed "ah ah ah," on the other, "ee ee ee." Then the loudspeakers would play "ah ah" or "ee ee." Even babies as young as 16 weeks would gaze at the face mouthing the corresponding sound. The study proved babies lip read, that language is not an isolated auditory process. It's a social act.

Setting up the experiment took a year and a half, and countless discussions in Italian restaurants. "We hovered over every data point like a grandparent hovering over the family recipes," Kuhl says. After surviving the arduous test of publishing their findings in Science, they decided to marry.

Do what works

Parents, don't panic. You needn't rush out to buy Mozart and "Baby Einstein" DVDs. There's no scientific research showing commercial products will make babies smarter, happier or more compassionate.

What works, Kuhl and Meltzoff say, is doing what you naturally do: Talk, coo, play and cuddle with your baby in a loving way. Grownups are designed to behave in ways that will allow babies to learn, they write in "Scientist in the Crib." For human beings, nurture IS our nature. Our unique evolutionary trick, our central adaptation, our greatest weapon in the struggle for survival is precisely our dazzling ability to learn when we are babies and teach when we are grownups.

"When you watch parents in relaxed settings, they do the right things," Kuhl says. "Mother-ese falls off their tongues. When adults are stressed, communication falters and social interaction falters."

Day care? "Groups have always reared children," Kuhl says. "The quality of day care matters, but if there's a small ratio of kids to caretakers, the critical social stuff happens, language happens."

Television? "Should a child be in front of a TV eight hours a day? I'll go on record: No." But, Kuhl says, we need more studies on how much TV is too much; whether certain programming can teach certain things at certain ages.

Clearly, babies learn best from humans. But why?

Three months ago, Milo, like all babies, was able to distinguish all 600 consonants, 200 vowels and 40 phonemes found in Spanish, Salish, Senegalese and every other language. On Milo's first birthday, he'll likely hear only the sounds common to English as his brain commits to his native tongue. The Spanish experiment is designed to see whether brief exposure to foreign language during a "critical window" will help Milo retain his ability to hear the "duh" "tuh" phonemes particular to Spanish.

Kuhl's earlier research found that 9-month-old American babies who played games with and were read to by Mandarin speakers could still hear Mandarin phonemes at 14 months after only a dozen 25-minute Mandarin sessions. A control group could not. Babies who were exposed to videotaped Mandarin could not.
So why does human connection make a difference?

"The hypothesis is that interaction is what sets the brain up to acquire learning," Kuhl says. "It's an opening of the cellular floodgates. ... There's this arousal thing ... that might do something biochemically that allows cells to acquire information in a more memorable way. We know that hormones play a role. We know that when children are apprehensive, under stress, they don't learn."

This is where Kuhl's work in language intersects with Meltzoff's research on imitation, social interaction and gaze.

Meltzoff's theory, based on earlier experiments: The sooner a baby follows the gaze of an adult, the quicker they'll learn language. "Say Mom looks up at a bird in the sky and says, 'Bird!' Baby knows that's a bird," Meltzoff says. "Eyes are the window to the soul. For many reasons, it's important to pay attention to where people are looking. Look! Mom's upset. What's she upset about? Where's she looking? People wear their emotions on their eyeballs."

Which leads to Meltzoff's theories on empathy. The newborn-tongue experiment proved babies understand the connection between self and other. Another Meltzoff experiment, with 18-month-olds, demonstrated babies understand other people's intentions. The babies watched adults try to pull apart a toy that had secretly been glued shut. Given the same toy, but not glued, the babies completed the task.

Those elements, Meltzoff says, are the roots of empathy. "Human beings are special in the animal kingdom, because we feel empathy for one another and have a theory of mind that says we believe other people have beliefs, thoughts, intentions, emotions, desires that are like mine but not the same. We don't think cats and dogs and fish are capable of that.

"The moral implications of this are profound. That person is thought to be like me. If they act like me, have feelings like me, then maybe they should be treated like I want to be treated."