The Choluteca Bridge (Puente Sol Naciente) in Honduras was built between 1996 and 1998 and designed to withstand the most powerful storms and hurricanes. In the very same year the bridge was completed, Honduras was struck by the catastrophic Hurricane Mitch. The bridge itself survived the hurricane with relatively minor damage, but the landscape surrounding it did not. Massive floods and landslides completely reshaped the terrain and diverted the course of the Choluteca River several hundred metres away. The river no longer flowed beneath the bridge, but beside it, while the access roads on both sides were completely destroyed. The bridge remained standing intact in the middle of dry land, a "bridge that leads nowhere and crosses nothing." In 2003, the bridge was finally reconnected to a new road system and redirected towards the river's new course.
Just as a river changes its course, first through the force of nature and later through human intervention, something remarkably similar happens through the neuroplasticity of our brain. When we repeat a particular habit, thought, or skill for years, the brain builds a "bridge", a strong, automated neural connection that, over time, becomes an old neural pathway. When major changes occur, as in the case of a brain injury, sudden stress, or simply a conscious decision to break a harmful habit, the previous way of functioning no longer serves its purpose because "the water no longer flows through the old riverbed." Just as the river carved a new path through the landscape, the brain, under the influence of new experiences and learning, creates entirely new neural networks, a new neural pathway. Neuroplasticity allows us to build new access roads and adapt our thoughts and behaviour to a new reality. The pathways of our mind are not carved in stone: just as the course of a river can change, the brain can reshape itself throughout our entire lives.
My twin daughters were born at 31 weeks and, almost thirty years ago, spent the first two months of their lives in hospital, nearly one of those months in an incubator. Naturally, they came home with a whole collection of rather unpleasant prognoses and diagnoses, but their story is perhaps one of the clearest examples I know of how neuroplasticity works in real life. They are almost a textbook example of functional neuroplasticity and what is known as brain reorganisation. When damage occurs early in life, certain neurons may be lost, but the brain of a young child has an extraordinary capacity to redirect functions. Under certain circumstances, other neural networks, including neighbouring regions, can gradually take over or support part of the function of the damaged area. Rehabilitation and repeated stimulation can help the brain through this process by continuously providing the stimuli it needs in order to learn and reorganise itself. At the time, we repeated the exercises three times a day for half an hour, and with every movement and every exercise we were sending a powerful signal to the brain: "We need this movement." Repeating those movements every single day encouraged the strengthening and reorganisation of neural connections. Repetition is not easy for either the parent or the child because it is enormously emotionally exhausting - at least it was for me. That moment when you are already repeating every exercise almost mechanically, no longer expecting anything to happen that day, and then suddenly your child performs that movement entirely on her own, without your help, is a feeling that cannot really be compared with anything else. At that moment, you are the happiest person in the world. That one tiny movement, something that comes naturally to a healthy child and that the rest of us take completely for granted, becomes an extraordinary gift for a child who is struggling to achieve it.
Alongside all that persistence and continuous work, we also had a little bit of luck, and luck is desperately needed. Work and effort alone are not always a guarantee, because there are severe diagnoses for which even the strongest will and the most relentless work cannot bring the outcome we desperately hope for. The miracle is not only in progress; the miracle is life itself and every single step within it. The intensive exercises continued until they were seven years old, after which swimming, dancing, and other activities gradually took their place. Today, my daughters are beautiful, independent young women preparing their doctoral dissertations. Their story remains, for me, one of the most beautiful examples of just how complex the human brain is and how extraordinary its capacity for adaptation can be.
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If we go back a little through history, neuroplasticity was not discovered at a single moment in time; our understanding of it developed gradually over several centuries. For a long time, scientists believed that the adult brain was "fixed" and irreversibly defined, but a series of important discoveries eventually transformed that scientific paradigm. As early as the late eighteenth century, the Italian anatomist Michele Vincenzo Malacarne provided one of the earliest indications that experience and training might be associated with changes in the brain. William James used the word plasticity in 1890, while Jerzy Konorski introduced the term neural plasticity in 1948. A year later, Donald Hebb laid the foundations for the principle that would later be summarised in the famous phrase: "neurons that fire together, wire together." During the 1960s and 1970s, scientists such as Marian Diamond, Paul Bach-y-Rita, and Michael Merzenich conducted crucial experiments that challenged the long-held image of the adult brain as an unchanging structure and demonstrated that neural networks can reorganise themselves in response to experience, learning, the environment, and injury.
In addition to the functional neuroplasticity mentioned above, today we also speak of structural plasticity - the brain's ability to change its physical structure under the influence of experience, learning, and repetition. While functional plasticity allows the brain to reorganise the way different regions perform particular functions, structural plasticity refers to changes within the neural connections and networks themselves. When we learn a new skill, develop a new habit, or persistently repeat something, certain neural connections can become stronger, others can weaken, and entirely new synaptic connections can also emerge. In other words, experience does not merely change what we know, it can also change the way our brain itself is organised.
Every time we learn something again and again, our brain, in a sense, leaves a trace of the path we have travelled. The more often we walk that path, the more familiar it becomes and the easier it is to travel again.
Neuroplasticity is one of the most powerful pieces of evidence that a human being is never a completely finished project. We cannot control everything that happens to us, but we can influence the pathways that we repeatedly create and strengthen through our experiences, learning, and repetition. By learning, practising, changing our habits, and changing the way we respond to the world, we also change the brain through which we experience that world. And by changing our brain, we change our world.