There’s always been a time in our lives when we thought, if given enough time, we’d learn a new language, a new instrument, acquire a new skill. Some of us have successfully accomplished this in the wake of the pandemic, and probably a few of us are somewhere in between — realizing that the whole thing is a lot harder than we ever anticipated and maybe it’s just out of our skill set — that we’re too old to learn new things and the whole thing is hopeless. Our brains have already reached their maximum capacity.
For many years, this was conventional wisdom even in the medical community, when it was thought that the brain was limited to how many connections it could make and what information it could hold, and that after a certain age, our brains are fully formed, with no extra materials left over. Fortunately, it’s far from the truth.
The brain’s ability to undergo biological changes — whether it’s rebuilding individual neurons at the cellular level, to the complete rewiring of entire regions of the brain, is known as “neuroplasticity.” The concept itself isn’t all that new either — the phrase was coined back in 1948 by the physiologist Jerzy Konorski. Konorski and his wife, physiologist Lilliana Lubinska, conducted a number of experiments together at their lab in Warsaw and believed that the brain could be conditioned to overcome forgetfulness and create new connections between regions after old ones grew weaker.
Unfortunately, Konorski and Lubinska weren’t able to see the brain as it functioned, but their experiments overlapped with the research of learning expert Donald Hebb, who proposed a similar theory around the same time. In the decades that followed, and as neuroscience grew as a field, researchers became interested in patients recovering from strokes, asking why some patients tended to make better recoveries than others — something we now know is due to portions of their brain being able to rewire in different ways. In recent years, with the advent of functional MRI technology, neuroscientists have distinguished between two types of neuroplasticity: “structural” and “functional.”
Structural plasticity refers to the brain’s ability to alter its neuronal connections. There are new neurons constantly being produced and incorporated into the central nervous system throughout one’s life. This is determined by the volume of gray matter found in the brain — a buildup of neurons, the glial cells that insulate and hold them together, as well as synapses and capillaries. It plays a role in both basic motor function and sensory perception.
Functional plasticity, however, is the brain’s ability to modify and adapt the functional properties of its neurons. These changes could be the result of activities done to acquire memory — such as when we take in the information needed to perform a new kind of task, like playing a new instrument — a phenomenon known as “activity-dependent plasticity,” or it could be to retrieve memories following the misfire or destruction of neurons, known as “reactive plasticity” — such as when an individual recovers from a stroke and needs to relearn some of their basic motor skills. It also describes the changes taking place when you learn how to juggle or how to play a new video game console.
Retracing Our Steps
So how does the brain go about reprogramming itself? Dr. Harriet Dempsey-Jones conducted a study with her colleagues at the University College London that surveyed an unlikely demographic: artists who had learned to paint using their feet due to the loss of a hand. Her team suspected that the answer lied somewhere in the brain’s somatosensory cortex, which acts like something of a switchboard between neurons across the various regions of the brain. In an analysis of the patients’ brains, Dempsey-Jones and colleagues made a unique discovery: specific areas of the human brain fused together in order to coordinate the fine-tuned movement of each toe.
These connections have their roots in a chapter of our evolutionary history that we share with monkeys who require the use of all fingers and toes as they leap from tree to tree. Since most of us have become acclimated to using just 10 fingers to navigate much of the world, however, the brain connections that coordinate our fingers are much more strongly pronounced than the ones in the toes, which are largely dormant and are pruned away over time as the brain makes new connections.
