After reading Doidge's book, Debbie began living what she calls a "brain-healthy" life. That includes yoga, meditation, visualisation, diet and the maintenance of a positive mental attitude. Today, she co-owns a yoga studio, has written an autobiography and a guide to "brain-healthy living" and runs the website thebestbrainpossible.com. The science of neuroplasticity, she says, has taught her that, "You're not stuck with the brain you're born with. You may be given certain genes but what you do in your life changes your brain. And that's the magic wand." Neuroplasticity, she says, "allows you to change your life and make happiness a reality. You can go from being a victim to a victor. It's like a superpower. It's like having X-ray vision."Debbie's not alone in her enthusiasm for neuroplasticity, which is what we call the brain's ability to change itself in response to things that happen in our environment. Claims for its benefits are widespread and startling. Half an hour on Google informs the curious browser that neuroplasticity is a "magical" scientific discovery that shows that our brains are not hard-wired like computers, as was once thought, but like "play-doh" or a "gooey butter cake." This means that "our thoughts can change the structure and function of our brains" and that by doing certain exercises we can actually, physically increase our brain's "strength, size and density." Neuroplasticity is a "series of miracles happening in your own cranium" that means we can be better salespeople and better athletes, and learn to love the taste of broccoli. It can treat eating disorders, prevent cancer, lower our risk of dementia by 60 percent and help us discover our "true essence of joy and peace." We can teach ourselves the "skill" of happiness and train our brains to be "awesome." And age is no limitation: neuroplasticity shows that "our minds are designed to improve as we get older." It doesn't even have to be difficult. "Simply by changing your route to work, shopping at a different grocery store, or using your non-dominant hand to comb your hair will increase your brain power." As the celebrity alternative-medicine guru Deepak Chopra has said, "Most people think that their brain is in charge of them. We say we are in charge of our brain.""You're not stuck with the brain you're born with. You may be given certain genes but what you do in your life changes your brain"
Debbie's story is a mystery. The techniques promising to change her brain via an understanding of the principles of neuroplasticity have clearly had tremendous positive effects for her. But is it true that neuroplasticity is a superpower, like X-ray vision? Can we really increase the weight of our brain just by thinking? Can we lower our risk of dementia by 60 per cent? And learn to love broccoli?Some of these seem like silly questions, but some of them don't. That's the problem. It's hard, for the non-scientist, to understand what exactly neuroplasticity is and what its potential truly is. "I've seen tremendous exaggeration," says Greg Downey, an anthropologist at Macquarie University and co-author of the popular blog Neuroanthropology. "People are so excited about neuroplasticity they talk themselves into believing anything."For many years, the consensus was that the human brain couldn't generate new cells once it reached adulthood. Once you were grown, you entered a state of neural decline. This was a view perhaps most famously expressed by the so-called founder of modern neuroscience, Santiago Ramón y Cajal. After an early interest in plasticity, he became sceptical, writing in 1928, "In adult centres the nerve paths are something fixed, ended, immutable. Everything may die, nothing may be regenerated. It is for the science of the future to change, if possible, this harsh decree." Cajal's gloomy prognosis was to rumble through the 20th century.It's hard for the non-scientist to understand what exactly neuroplasticity is and what its potential truly is
But Cajal's prognosis also contained a challenge. And it wasn't until the 1960s that the "science of the future" first began to rise to it. Two stubborn pioneers, whose tales are recounted so effectively in Doidge's bestseller, were Paul Bach-y-Rita and Michael Merzenich. Bach-y-Rita is perhaps best known for his work helping blind people 'see' in a new and radically different way. Rather than receiving information about the world from the eyes, he wondered if they could take it in in the form of vibrations on their skin. They'd sit on a chair and lean back on a metal sheet. Pressing up against the back side of that metal sheet were 400 plates that would vibrate in accord with the way an object was moving. As Bach-y-Rita's devices became more sophisticated (the most recent version sits on the tongue), congenitally blind people began to report having the experience of 'seeing' in three dimensions. It wasn't until the advent of brain-scanning technology that scientists began to see evidence for this incredible hypothesis: that information seemed to be being processed in the visual cortex. Although this hypothesis is yet to be firmly established, it seems as if their brains had rewired themselves in a radical and useful way that had long been thought impossible.Merzenich and Bach-y-Rita proved the scientific consensus was wrong. The adult brain was plastic. It could rewire itself, sometimes radically
Adding extra tangle to the already confused public discussion of neuroplasticity is the fact that the word itself can mean several things
One way in which science has been exaggerated has been by the blending of these different types of change. Some writers have made it seem as if almost anything counts as 'neuroplasticity,' and therefore revolutionary and magical and newsworthy. But it's definitely not news, for example, that the brain is highly affected by its environment when we're young. Nevertheless, in The Brain that Changes Itself Norman Doidge observes the wide variety of human sexual interests and calls it "sexual plasticity." Neuroscientist Sophie Scott, Deputy Director of London's Institute of Cognitive Neuroscience, is dubious. "That's just the effect of growing up on your brain," she says. Doidge even uses neuroplasticity to explain cultural changes, such as the broad acceptance in the modern age that we marry for romantic love, rather than socioeconomic convenience. "That isn't neuroplasticity," says Scott.The truth is neuroplasticity does exist, and it does work, but it's not a miracle discovery that can turn you into a broccoli-loving, disease-immune genius
Another limitation, for the person hoping to develop a superpower, is the simple fact that every part of a normal brain is already occupied. "The reason you get reorganisation after an amputation, for example, is that you've just put into unemployment a section of the somatosensory cortex," he says. A healthy brain just doesn't have this available real estate. "Because it keeps getting used for what it's being used for, you can't train it to do something else. It's already doing something."Age, too, presents a problem. "Over time, plastic sets," says Downey. "You start off with more of it and space for movement slowly decreases. That's why a brain injury at 25 is a total different ballgame to a brain injury at seven. Plasticity says you start off with a lot of potential but you're laying down a future that's going to become increasingly determined by what you've done before."Robertson speaks of treating a famous writer and historian who'd had a stroke. "He completely lost the capacity for all expressive language," he says. "He couldn't say a word, he couldn't write. He had a huge amount of therapy and no amount of stimulation could really recover that because the brain had become hyper-specialised and a whole network had developed for the highly refined production of language." Despite what the currents of our culture might insistently beckon us towards believing, the brain is not Play-Doh. "You can't open up new areas of it," says McManus. "You can't extend it into different parts. The brain isn't a mass of grey gloop. You can't do anything you like."Even the people whose lives are being transformed by neuroplasticity are finding that brain change is anything but easy. Take recovery from a stroke. "If you're going to recover the use of an arm, you may need to move that arm tens of thousands of times before it begins to learn new neural pathways to do that," says Downey. "And, after that, there's no guarantee it's going to work." Scott says something similar about speech and language therapy. "There were dark days, say, 50 years ago, where if you'd had a stroke you didn't get that kind of treatment other than to stop you choking because they'd decided it doesn't work. But now it's becoming absolutely clear that it does, and that it's a phenomenally good thing. But none of it comes for free."Those who over-evangelise emerging disciplines like neuroplasticity or epigenetics can sometimes be guilty of talking as if the influence of our genes no longer matters. Their enthusiasm can make it seem, to the non-specialist, as if nurture can easily conquer nature. This is a story that attracts people in great numbers, to newspapers, blogs and gurus, because it's one our culture reinforces, and one we want to believe: that radical personal transformation is possible, that we have the potential to be whoever and whatever we want to be, that we can find happiness, success, salvation—all we need to do is try. We are dreamers down to our very synapses, we are the people of the American Dream.Of course, it's our malleable brains that have moulded themselves to these rhythms. As we grow up, the optimistic myths of our culture become so embedded in our sense of self that we can lose touch with the fact that they are just myths. The irony is that when scientists carefully describe the blind seeing and the deaf hearing, and we hear it as talk of wild miracles, it's the fault of our neuroplasticity.This story originally appeared on Mosaic with the headline, "Can you think yourself into a different person?" It is published under a CC BY 4.0 license.Despite what the currents of our culture might insistently beckon us towards believing, the brain is not Play-Doh