Authors: Michael Erard
When I was setting up my visit with Katrin Amunts, I told her I was visiting Cox. She responded with an excited, almost gustatory email: We can scan his brain!
This was exciting. As far as I could tell, the most languages seen at work in a scan of a single brain was four,
in a group of Swiss men and women. Different languages activated overlapping areas of the brain, and the more fluent languages activated a more central area. Studying someone with more than four languages would put us at the brink of a true frontier.
The next day, Amunts wrote back: Forget about scanning Cox.
At the time, I’d been puzzled. Now, sitting across from her, I could ask, “When you
wrote back saying no, was that because it would produce another case study?”
Amunts smiled. At first, she said, she felt the same excitement about Cox as with Krebs’s brain. “
Of course
I’m interested, and of course we could do all these fancy tests on language, cognitive abilities, general intelligence.” Ultimately, though, she decided not to pursue it, because “we would arrive at the same point,
that it is a case.
A case
.”
The ugly history of the study of elite brains had surfaced. Many scientists have been motivated by ideological arguments about the superior intelligence and culture of this country or that race, Zilles explained, which the natural historian Stephen Jay Gould had taken up in his 1981 book
The Mismeasure of Man
. Too many bad studies on elite brains have made journals
cautious, Amunts said. No one wanted to publish a study on just one genius, especially one on a German genius by German authors.
I saw the opportunity immediately, but Loraine spoke first. “Suppose you had
three
people,” she said.
The atmosphere in the room visibly shifted. I quickly added, “I’m in contact with five people who claim at least two dozen languages.” I knew I’d meet more. (And I
did.)
“Two dozen languages,” Amunts whispered, then turned to Zilles and muttered in German.
We’d want to look at functional connectivity, glucose, and oxygen use, Zilles said. We’d want to know how parts of the brain communicated with each other. It might be, he suggested, that a language-gifted person has more or faster connections in certain areas than a normal person. We’d have to test their
language proficiency, of course. It would be good to have a range of ages and native languages, too. As we talked, it all seemed possible. The world’s first neuroimaging study of a sizable group of hyperpolyglots dawned in front of us. A door into the future had opened, and if we seized the opportunity, we would do something that science had never attempted before.
“Let’s do it,” Zilles said.
Silence in the room. Maybe the rain was coming down, but I’d stopped hearing it. We were finally going to get the brains of hyperpolyglots to speak for themselves.
When the meeting was over, Zilles took Loraine and me upstairs to the brain library, a quiet, grayish room where rows and rows of small wooden boxes sat on metal shelves. Here, human brains, Zilles said; there, brains of the great primates
who’d lived in zoos. He seemed proudest of the major collection of insect eaters and bats. “A very rare collection,” he said. He took down a box from the human section, opened it, pulled out one of the glass plates, about five by seven inches, and put it under a microscope. Loraine and I took turns peering at the gray, grainy amalgam of the cortical slice.
But focusing on what was in front of
me was difficult—I was thinking about the living, breathing brains we’d finally get to see in action. And which, someday, when the Oskar Vogts of the future came asking for them, might settle into collections of their own.
Even though Krebs’s brain had a very different cell structure from normal brains, it wasn’t clear whether those differences might have existed before he encountered his first
foreign language. I asked our German hosts about this. “How long would it take for Krebs’s brain to develop like that? Could it happen in a year? Or is that the lifetime of change?”
“That’s an interesting question,” Loraine said. “Or was he born like that?”
Zilles said he didn’t know. Such changes can come from training, he said. They can also emerge quickly—cellular-level changes in the brains
of pianists, for instance, can occur in a matter of weeks. And intensive use gives musicians different brains from nonmusicians’ brains. Studies of rats have shown that training increases the number of synapses and glial cells and makes the capillaries supplying oxygen denser. Jugglers and taxi drivers have markedly different brains from nonjuggling, non-taxi-drivers. Persistent overuse could
be a simple reason for the cells’ peculiar arrangement as well as his brain’s remarkable symmetries.
“When you look at a histological section, you see the cell bodies that are stained, and in the cell bodies there is unstained tissue,” he said. “But there is something there, in those unstained areas. There are dendrites. There are synapses, and the glial cells, and the blood vessels. But most
of this volume is for dendrites, synapses. For contacts. These contacts are very fast-moving structures, so such a synapse can change within hours. When you do training, then you will get an effect on the synapses, and so the space between the cell bodies changes its size.”
Amunts disagreed with her colleague. To her, Krebs’s cytoarchitecture could have caused or enabled his linguistic predisposition,
instead of resulting from it. His parents were neither educated nor rich; other people paid for his schooling. If the story of Krebs and the French newspaper was to be believed, he brought a distinct cognitive foundation to learning foreign languages very early on.
“I’m convinced that there’s something in his genes,” she said. “You cannot say this is only the environment. That is rather simplistic.”
Here the story of Krebs’s abilities might have stalled in another endless round of arguments about the primacy of nature or nurture. In the popular mind, only one of these can drive outcomes, not both. Meanwhile, scientists are trying to describe how biological resources and experiences in the environment interact, on what schedule, and with what impact. It turns out that genetic mechanisms not
only make you; they also determine the range by which you can be made by your environment.
One such genetic trait that Krebs might have possessed was the way
his brain regulated its plasticity—how sculptable and moldable his brain was in response to things in his environment. Overall, his tendency toward more or less malleability would be driven by genetic factors. No matter how someone without
that plasticity practices, they won’t be able to speed it up or make it stick more. It’s widely known that babies and other young animals have an “exuberant plasticity” that allows them to learn about their world very quickly. Yet neuroscientists now also think that the brain’s essence—at any age—is to be changeable. What happens in adulthood is that the plasticity has been “braked” for one very
good reason: in order to survive and succeed, adults have to have a certain amount of reliable neural structure that is usable over months and years. One of the ways that Krebs’s brain might have been unusual was that it preserved more of its childhood plasticity.
Even among normal learners, there’s a lot of variation between individuals when the malleability of childhood hardens. Bilingual kids
also enjoy an advantage in remaining open to new language input. And, in some rare cases, language learners appear to enjoy a plasticity past the point where it’s shut off for others. Unfortunately, because linguists have been most fascinated with the acquisition of native-like skills, more is known about people who are able to learn one or two more languages very deeply rather than about those
who can acquire a good working knowledge in a larger set. Again, it was the bias for the “all or nothing” view over the “something and something” view of language abilities.
Young humans use their exuberant plasticity for learning many things; one of the most important is for language. The notion of a critical period for language learning was first formulated in the 1960s by linguist Eric Lenneberg.
“Automatic acquisition from mere exposure to a given language seems to disappear after [puberty], and foreign languages have to be taught and learned through a conscious and labored effort,” Lenneberg wrote. The exact nature of this critical period for language has long been debated, even though its biological mechanism isn’t known. One limit is puberty, which means hormones are likely involved.
But is puberty the end of plasticity or simply the beginning of the end? No one knows for sure.
Ever since Lenneberg, researchers in second-language acquisition have taken the adult’s decline in plasticity—the closing of the critical period window—to refer almost exclusively to the impossibility of learning a language like a native speaker. Even though the brain has no native languages, only
focused activity in certain neural circuits,
linguists have looked only at how “linguistic insiders” are produced
. Some researchers have even fiercely defended the claim that no one who begins learning a language outside the critical period will ever have native-like abilities. In one recent study of Swedish learners, none of the adult learners passed a nativeness test, and only 3 of the 107 child
learners did. If a child learning Swedish can’t become a native speaker, then who can?
Opponents of the critical period hypothesis have taken on these claims directly—by trying to find adults who have, in fact, achieved nativeness in languages they didn’t grow up with. Some have figured that only 5 percent of adult learners can do this. Some put the number even lower, at fewer than 1 percent.
Even so, these opponents are bound by “nativeness” as the sole criterion of success at learning a language—they’ve let the proponents of the hypothesis set the terms by which the debate is waged.
In one recent dissertation, forty-three non-native speakers of Dutch, a language they’d started learning after the age of twelve, were asked to do some tasks with a type of sentence that’s hard for people
to learn.
*
If you knew languages close to Dutch, as some participants did, you could borrow and apply what you know. If your native language was one like Turkish, you’d have nothing to fall back on. Your language lacks this sentence structure completely. Of the forty-three, nineteen were able to produce this kind of sentence like native speakers did. Most were
women; most were also more likely
to speak German and French than Turkish, and had spoken Dutch for a long time. Interestingly, all had either studied a third language as well, or had worked as teachers, translators, or some other language-related job. This was significant, because the answer didn’t lie in their fondness for languages—every single one of the forty-three subjects had said that they liked to learn languages.
In
another project, an exhaustive battery of proficiency tests was given to nine non-native English speakers who’d been mentioned or referred to the researcher as having excellent English. All nine had learned English after age sixteen and had lived in the United States for at least five years. Only three of them performed like native English speakers on tests of grammar, pronunciation, vocabulary size,
politeness, and storytelling. All three were women. They were all from Eastern Europe, had studied English for at least five years before coming to the United States, and lived with native English speakers (two of the three were married). They also used their first languages infrequently.
For these cases, what predicted good English was using a lot of English. No other biological factor—gender
or age of arrival—predicted good English or vocabulary size. You just had to live longer in the States, preferably with a native speaker. On the surface, it appeared to be a victory for the power of practice and immersive experience to trigger changes in the brain. But other individuals might share those same biographical facts and still not speak English well enough to be referred for a study.
The studies didn’t provide a cognitive profile of the high performers, either. They couldn’t speak to the cognitive skills that those individuals brought to their tasks, nor could they account for how one person’s brain might be more plastic than another. Could a measurement of brain plasticity be a better way to predict language learning outcomes?
One day, after my trip to Germany, I was at
home in the apartment, dealing with a clogged bathroom sink. The landlord came over with his son-in-law to fix it. In the course of chatting, the landlord asked what I was working on, and I told him, a book about people who speak a lot of languages. Really? my landlord said. He speaks a lot of languages, he
said, pointing to his son-in-law, who was half sticking out of the cabinet. He’s from Iran,
and he’s lived all over. He speaks six or seven languages. He’s a genius.
Is that true? I asked the son-in-law.
Yeah, it’s true, he said, from under the sink.
How many languages can someone learn? So far, I’d pursued an answer among massive accumulators and high-intensity learners, many of whom came from monolingual communities. I knew little about places where normal people, inheritors of
a normal biological endowment, regularly learn to speak many languages. I knew I had to venture out for a closer look to see what else I could learn about the brains of Babel.
Part 4
ELABORATION:
The Brains of Babel
Chapter 15
O
ver the palm trees, the sun was barely squinting, and already the traffic lashed the dusty intersection in front of the Hotel Diamond Point. Streams of small trucks; battered motorcycles; shiny compact cars; yellow, three-wheeled auto-rickshaws; scooters; bicycles; pedestrians; and the occasional oxcart converged from five directions onto the same point, creating a chaotic whirlpool
in the middle of the intersection. No signs channeled the crush, no lights controlled it; there were no lanes, hardly even curbs.
I was watching this on the street in Secunderabad, a south Indian city whose entire population seemed to be trying to pass in front of the hotel in one unstoppable throng, at that very moment. When you’re in a vehicle, the traffic feels crushing; then you realize that
you’re not being crushed; then that you’re making slow progress toward your goal. After a couple days of crossing Secunderabad and neighboring Hyderabad (with a population of four million) on roads like this, you realize that the visible chaos has predictable patterns. Maybe that’s what kept drivers so eerily calm as they headed into the whirlpool—keep your speed, make no sudden movements, and
you might stay safe. Maybe the policeman, a lone man in a white hat, shaped these flows. No, I realized, he’s just a
witness to the gridlock’s wonder. On a giant poster high on a building, the face of a beatific swami gazed upon the waves of disorder.