Look at any baby, lying on its back, gurgling and dribbling and peering around the room like a drunken gremlin. It’s probably listening to you, and if you speak, its little mind will be learning from you.
In fact, we now know that our brains begin absorbing the melodies of language and noticing its most common sounds from the earliest days of life. By the age of just six months, that baby should have learned what words are by working out how to break up the continuous streams of sound emerging from other humans’ mouths.
From there, she or he can begin to understand what they mean, before one eventually creeps out of their own throat for the first time.
Among the labs involved was the Neurospin facility near Paris. Its director, Professor Stanislas Dehaene, one of Europe’s most respected cognitive scientists who has led pioneering research into how we understand maths, could not be clearer about what findings like these show us: the newborn’s mind is not a blank slate. On the contrary, the human brain comes pre-armed with “considerable knowledge inherited from its long evolutionary history,” he writes in his new book, How We Learn.
In one of the most striking examples, Dehaene states: “Right at birth, babies can tell the difference between most vowels and consonants in every language in the world.” It sounds incredible. How can helpless babies possibly possess knowledge like this?
He details many experiments, including one carried out by a fellow scientist who is also his wife, Professor Ghislaine Dehaene-Lambertz, in which premature babies’ heads were fitted with sensors to monitor electrical activity and blood flow. She discovered “that even babies born two and a half months before term respond to spoken language: their brain, although immature, already reacts to changes in syllables as well as in voices.”
It goes beyond language. Newborns also possess built-in understanding of objects, numbers and even probabilities. “Babies’ brains already know the laws of physics,” writes Dehaene.
It sounds unlikely - but then why would infants react with surprise when they see magic tricks, if they didn’t already understand that objects can’t just disappear or pass through each other? Studies have analysed those expressions of wonder, and how babies react to changes in numbers and when statistically improbable things happen.
We can even see how facial recognition skills develop before birth. Shine three lights through the wall of the uterus, positioned in the pattern of two eyes and a mouth, and a foetus is more likely to be attracted to them than if they’re arranged in the shape of a pyramid.
This research isn’t being conducted out of pure curiosity. The questions driving Dehaene and other neuroscientists to find out more about our brains and how they develop are important and plentiful. How can we improve our treatments of medical conditions? Could we change our education systems to teach more effectively? What ideas can designers of supercomputers take from how our bodies function?
Speaking to i from his Neurospin office, Dehaene’s enthusiasm and wonder at what goes on inside our skulls is inspirational, even at the end of a long day after he’s returned from a conference. “The brain,” he says, “is the most complex object in the known universe.”
Unravelling our mental mysteries requires some of the most advanced machinery ever constructed. Neurospin has six MRI scanners to look into our heads using magnetic fields and radio waves. It is one of the few places in the world that can do this for babies’ brains. People of all ages are examined, however - including 54-year-old Dehaene himself.
“I have a scan from 17 years ago and a scan from two weeks ago. Fortunately my brain still looks healthy - I haven’t aged too much,” he says.
Neurospin is currently installing the biggest MRI scanner in the world, five metres (16 feet) in diameter, which should be operational by 2022. Its size matters, because the stronger the magnetic field, the more detailed the scans will be.
“At the moment, we scan the brain at the resolution of approximately one millimetre,” Dehaene explains. “There are tens of thousands of neurons within each of these cubic millimetres. In that respect the scans are still very coarse, because the neuron is the unit of coding in the brain. We need to look at assemblies of neurons and be able to decode much more finely than we’re able to do now.
“It’s a rather extraordinary machine,” he adds of the new scanner, named Iseult. “The people who designed it are the people who designed the magnets at Cern.”
So is this the brain equivalent of Cern’s Large Hadron Collider, the vast, £6bn underground device in Switzerland which confirmed the existence of the Higgs boson, the so-called “God particle”?
“Well, it’s much cheaper,” Dehaene says with a laugh. “But I think the proportions are a bit like that. We are chasing the unknown.”
One of the biggest conundrums in all science, not just the neuro variety, is how consciousness works. How do we form our sense of the world around us and of our own existence?
It’s a topic that philosophers have considered for centuries - it was another Frenchman, René Descartes, who coined the phrase “Cogito, ergo sum” or “I think, therefore I am”. But it is now coming under greater scientific scrutiny than ever before.
For example, says Dehaene, it’s “amazing” that we “give people anaesthetics, but we still don’t understand what they do to the brain” - and most worryingly, why sometimes they don’t work, leaving people awake and often able to feel the pain of their operations. “They are paralysed but they’re still conscious, and it is a traumatic experience.”
Research has found that this might affect 5 per cent of all patients who are given anaesthetic - causing pain in almost half of these cases - though mercifully many of them cannot remember it afterwards.
Dehaene hopes his work will also help us in “understanding coma, understanding vegetative state, finding out who is ‘locked in’ and cannot communicate but is still conscious”.
Research has already led to useful technology being deployed in hospitals. “We have devices that use brain imaging to predict whether a patient is still conscious or not, and also to predict the recovery of consciousness,” he points out.
However, there remains a divide in the research community over which parts of the brain are most important to consciousness, and how it works. To resolve this, a $20m project to test two theories was announced by the Templeton World Charity Foundation in October last year.
Dehaene is seen as the world leader behind the global workspace theory (GWT), while Giulio Tononi of the University of Wisconsin-Madison has put forward the competitor: the integrated information theory (IIT).
As the journal Science explained following the announcement of the Templeton prize: “The GWT says the brain’s prefrontal cortex, which controls higher order cognitive processes like decision-making, acts as a central computer that collects and prioritises information from sensory input. It then broadcasts the information to other parts of the brain that carry out tasks. Dehaene thinks this selection process is what we perceive as consciousness.
“By contrast, the IIT proposes that consciousness arises from the interconnectedness of brain networks. The more neurons interact with one another, the more a being feels conscious - even without sensory input. IIT proponents suspect this process occurs in the back of the brain, where neurons connect in a grid structure.”
So how confident is Dehaene that his proposal will win? “Well, there’s still a lot of debate,” he says. “But the fact that we are able to predict to a large degree which patients are conscious or unconscious based on the theory makes me a little bit…” He pauses, perhaps wary of hubris in predicting victory. “I think we have cracked the box open. There are many states of consciousness that remain under study.”
What is his relationship like with his rivals? “We get along very well. We are all interested in the truth,” he says. “And I tell you one thing: I think it’s quite possible that in the end, we will find that we’re not talking about exactly the same thing. Part of the scientific process is to take words like ‘consciousness’ and to redefine them from the point of view of science. And in doing so, sometimes we find that there are two different concepts.”
When the subject is as intangible and complicated as consciousness, even scientists can struggle to define what exactly they are studying.
Dehaene’s work is celebrated by his peers. Uta Frith, emeritus professor of cognitive development at University College London, who like Dehaene is a fellow of the British Academy, tells i that he “has done more for educational neuroscience than anyone else. His groundbreaking work on literacy tells us how the brain changes with learning to read, while his work on maths has thrown light on the sense of number.”
Dehaene himself is determined that his research should prove to be useful in the real world. That’s why he is disappointed that significant research findings revealing how we learn have not led to changes and improvements in how we teach in schools, to improve education not only for the benefit of children but for the society they will grow into.
“There is a huge distance between the lab discoveries and the classroom,” he says. “We need to progressively fill this gap.”
He admits putting research to real-world use isn’t easy. “It’s just like in pharmacological science - you get a drug that seems to work in the petri dish but then doesn’t work with the whole person, or it works in mice but not in humans.”
Two simple but crucial factors he thinks everyone should embrace when trying to learn something new are how important it is to consolidate the knowledge you’ve already gained as you take new steps, and recognising the value of sleep for our brains to be able to absorb and process new information.
Dehaene and his wife have three sons, and watching them learn as they grew up “made me super-curious in everything that they were doing,” he says. “We were often doing many experiments in the home, especially as my wife is also a scientist. We did wonderful brain teasers.
“Now the boys are 25, 28 and 30. My kids all became engineers and mathematicians for some reason.”
Sometimes resistance to new teaching methods also has to be overcome within traditionalist education circles, and Dehaene cites phonics as an example. This is the method of learning to read by linking sounds, or phonemes, and the letter groups that represent them, graphemes - sometimes mixing real words with made-up ones.
Phonics is sometimes viewed with suspicion - when phonics testing was introduced to the English curriculum by Michael Gove during his time as Education Secretary, authors including Michael Morpurgo and Philip Pullman criticised the focus on this technique - but it has now become standard practice.
“We’ve known for about 30 years that phonics is superior,” says Dehaene. But but he says “confusion” over how it works delayed its introduction. “Once teachers understand it, then they are quite happy, I think.”
More broadly, Dehaene feels that we all suffer when science - of any field - is ignored or undermined, perhaps because of populism, fear or a sheer lack of will to understand it.
“I am quite shocked that the political spheres often lack knowledge of science, are often very ignorant of science. In fact, sometimes they’re quite proud of it. It’s always intriguing how you can brag about not being good in maths,” he says.
“When we look at the climate crisis, for instance, in retrospect we can see that for 30 years or more the scientists have been right. All of the curves that we are now lamenting were actually predicted, fully, right on track. Science is an extremely powerful way of telling the truth, whether you like it or not, and I wish that people were listening a bit more.
“There’s one message in the book that I’d like people to remember,” he concludes. “Don’t underestimate your kids or your pupils. Their brains are supercomputers. They know much more than you think.”