Being a different person?

“I can look back on giving lectures at Edinburgh University to students where I gave wrong information, based on the dogma which said that, once dead, a brain cell cannot regenerate and plasticity happens in early childhood but not later,” he says.

It wasn’t until the publication of a series of vivid studies involving brain scans that this new truth began to be encoded into the synapses of the masses.

In 1995, neuropsychologist Thomas Elbert published his work on string players that showed the “maps” in their brain that represented each finger of the left hand — which they used for fingering — were enlarged compared with those of non-musicians (and compared with their own right hands, not involved in fingering). This demonstrated their brains had rewired themselves as a result of their many hours of practice.

Three years later, a Swedish– American team, led by Peter Eriksson of Sahlgrenska University Hospital, published a study in Nature that showed, for the very first time, neurogenesis — the creation of new brain cells — was possible in adults.

In 2006, a team led by Eleanor Maguire at the Institute of Neurology at University College London found that the city’s taxi drivers have more grey matter in one hippocampal area than bus drivers, because of their incredible spatial knowledge of London’s maze of streets.

“Neuroplasticity is a constant feature of the very essence of human behaviour,” says Robertson.

This understanding of the brain’s power, he says, opens up new techniques for treating a potentially spectacular array of illnesses. “There’s virtually no disease or injury, I believe, where the potential doesn’t exist for very intelligent application of stimulation to the brain via behaviour, possibly combined with other stimulation.”

Does he agree that the power of positive thinking has now gained scientific credibility? “My short answer is yes,” he says. “I do think human beings have much more control over their brain function than has been appreciated.”

The long answer is: yes, but with caveats.

First, there’s the influence of our genes. “My own crude rule of thumb is a 50–50 split in terms of the influence of nature and that of nurture,” Robertson says. “But we should be very positive about that 50% that’s environmental.”

Adding an extra tangle to the already confused public discussion of neuroplasticity is the fact that the word itself can mean several things. Broadly, says SarahJayne Blakemore, deputy director of London’s Institute of Cognitive Neuroscience, it refers to “the ability of the brain to adapt to changing environmental stimuli”.

But the brain can adapt in many different ways.

Neuroplasticity can refer to structural changes, such as when neurons are created or die off, or when synaptic connections are created, strengthened or pruned. It can also refer to functional reorganisation, such as those experienced by the blind patients of Paul Bach-y-Rita, whose contraptions triggered their brains to start using their visual cortices, which had previously been redundant.

On the larger, developmental scale, there are two categories of neuroplasticity. They are “really different”, says Blakemore. “You need to differentiate between them.”

Throughout childhood our brains undergo a phase of “experienceexpectant” plasticity. They “expect” to learn certain important things from the environment, at certain stages, such as how to speak. Our brains don’t finish developing in this way until around our mid-20s.

“That’s why car insurance premiums are so high for people under 25,” says Robertson. “Their frontal lobes aren’t fully wired up to the rest of their brains until then. Their whole capacity for anticipating risk and impulsivity isn’t there.”

Then there’s “experience-dependent” plasticity. Blakemore explains: “That’s what the brain does whenever we learn something, or whenever something changes in the environment.”

The “deep question”, says Chris McManus, professor of psychology and medical education at University College London, is: “Why do people, even scientists, want to believe all this?

“People have all sorts of dreams and fantasies and I don’t think we’re very good at achieving them,” says McManus. “But we like to think that when somebody is unsuccessful in life they can transform themselves and become successful.

“It’s Samuel Smiles, isn’t it? That book he wrote, Self-Help, was the positive thinking of Victorian times.”

This myth — that we can be whoever we want to be, and achieve our dreams, as long as we have sufficient self-belief — emerges again and again, in our novels, films and news, and TV singing competitions featuring Simon Cowell, as well as unexpected crazes like that for neuroplasticity.

One previous, and remarkably similar, incarnation was neurolinguistic programming, which had it that psychological conditions such as depression were nothing more than patterns learned by the brain and that success and happiness were just a matter of reprogramming it. The idea appeared in a more academic costume, according to McManus, in the form of what’s known as the standard social science model. “This is the idea from the 1990s where, in effect, all human behaviour is infi- nitely malleable and genes play no role at all.”

But the plasticity boosters have an answer to the tricky question of genes, and their heavy influence over all matters of health, life and wellbeing. Their answer is epigenetics. This is the relatively new understanding of the ways in which the environment can change how genes express themselves.

The alternative medicine advocate, Deepak Chopra, has said that epigenetics has shown us that, “regardless of the nature of the genes we inherit from our parents, dynamic change at this level allows us almost unlimited influence on our fate”.

But Jonathan Mill, professor of epigenetics at the University of Exeter in the United Kingdom dismisses this kind of claim as “babble”. “It’s a really exciting science,” he says, “but to say these things are going to totally rewire your whole brain and gene functioning is taking it way too far.”

Not all treatments are created equal. Just as epigenetics doesn’t fulfil our culture’s promise of personal transformation, nor does neuroplasticity.

Even some of the more crediblesounding claims are, according to Robertson, currently unjustifiable. Take the one about reducing our risk of dementia by 60%. “There’s not a single scientific study that has ever shown that any intervention of any kind can reduce the risk of dementia by 60%, or indeed by any percentage,” he says. “No one has done the research using appropriate controlgroup methodologies to show that there is any cause-and-effect link.”

Indeed, the clinical record for many famous treatments that use the principles of neuroplasticity is notably mixed. In June 2015, the Food and Drug Administration in the United States permitted the marketing of the latest iteration of Bach-yRita’s on-the-tongue “seeing” devices for the blind, citing successful studies. And yet a 2015 Cochrane Review of constraint-induced movement therapy — a touchstone treatment for neuroplasticity evangelists that offers improvements in motor function for people who have had a stroke — found that “these benefits did not convincingly reduce disability”.

It’s perhaps understandable that crazy levels of hope are raised when people read tales of apparently miraculous recovery from brain injury that feature people seeing again, hearing again, walking again, and so on. These dramatic accounts can make it sound as if anything is possible.

But what’s usually being described, in these instances, is a specific form of neuroplasticity — functional reorganisation — which can happen only in certain circumstances. “The limits are partly architectural,” says Greg Downey. “Certain parts of the brain are better at doing certain kinds of things, and part of that comes simply from where they are.”

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 totally 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 about 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 hyperspecialised and a whole network had developed for the highly refined production of language.”

But 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.”

Neuroscientist Sophie Scott, deputy director of London’s Institute of Cognitive Neuroscience, 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 overevangelise emerging disciplines such as 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 nonspecialist, as if nurture can easily conquer nature.

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.