Beyond hardwired: Explore the science of neuroplasticity and how to leverage it for change.

What is plasticity?

The idea that the brain can change its own structure and function through thought and activity is, I believe, the most important alteration in our view of the brain since we first sketched out its basic anatomy and the workings of its basic component, the neuron.

I can hear you ask, what the hell is plasticity?

Neuroplasticity as a term is derived from the combination of words neuro as in “neuron” the nerve cells in our brains and plastic for “changeable, modifiable”. It refers to the brain’s ability to change its own structure and function by forming new neural connections through thought and activity.

At its core, the theory of neuroplasticity, has been challenging the traditional belief that our brains work like computers with a set memory and processing powers. However, over the last half-century, scientific discoveries have been consistently confirming that our brains possess the ability of changing themselves through our personal experiences and thoughts.

What this means is, we are not “stuck” with the brains that we have been given at birth.

This revolutionary work has set the stage for life-altering inventions and interventions that affect human life; like cochlear implants that allow the deaf to hear, rewiring of the brain to overcome obsessions, traumas and learning disabilities, as well as assisting stroke survivors in regaining mobility.

It is an incredibly powerful ability that potentially allows us to change ourselves in anyway we want.

However, according to Doidge, this power is also the reason for our most stubborn habits and disorders. He claims, once a particular plastic change becomes well established in our brains, it can hinder other potential changes.

In the following parts I will explain how “critical period” works for children and how competitive plasticity affects us as adults.

Let’s begin.

Brain's Learning Phase: Critical Period

The brain’s greatest period of learning is not university, not medical school, not law school, but the period from birth to six.

Marian Diamond

A definitive scientific evidence on plasticity, although hinted in many pieces of research, has not emerged until the 1960s.

One of these crucial research mentioned in the book is David Hubel and Torsten Wiesel’s research on Optical Development in Kittens. Hubel and Wiesel were using microelectrodes into visual cortex of kittens in order to micromap the visual cortex and learn how vision is processed. During their research, they discovered that there is a “critical period” from third to eighth week of life when the newborn kitten’s brain had to receive visual stimulation to develop normally.

In their research, they first denied one eye of the kitten the visual stimulation. When they later on provided the visual stimulation to this eye, they figured out that visual areas in the brain map that normally processed input from closed eye had failed to develop, leaving the kitten blind in that eye for life. Surprisingly, when they examined the brain map for the blind eye, they realised the brain did not stay idle and it began to process visual input from the working eye, clearly proving that the brain was plastic and its structure literally shaped by experience.

The discovery of “critical period” changed medical practice. Children born with cataracts no longer faced blindness, instead they went through corrective surgeries and got the necessary light to form crucial neural connections.

Hubel & Wiesel received a Nobel prize for their work. And, as a result of this discovery, the critical period became famous in late 1900s and a lot of research on other neural systems has been done. Since then, it has been proven that each neural system had different critical period, during which it was especially plastic, sensitive to the environment and had rapid formative growth.

For example, critical period for language development begins in infancy and ends between eighth years and puberty. What this means is, after puberty we start having problems learning a new language. In fact, according to the book, our brains store the language that we learn in our critical periods, in different location than the other languages we learn after the critical period. This is one of the reasons why we have trouble learning a new language in our adult lives.

While critical periods are extremely important in early phases of life, it does not permanently close the doors on learning later in life. Plasticity is the default function of the brain and we can always shape it by adapting our behaviours and habits.

Also, I will not be mentioning it in this issue, but Doidge also mentions other experiments that successfully “reactivated” critical periods in adult life. If you are interested in it, let me know with the button below, or writing me an email/DM and I will write about it.

Anyway, let’s now look at how plasticity works for adults.

There is a turf war going on in your brain right now

The brain is not an inanimate vessel that we fill; rather it is more like a living creature with an appetite, one that can grow and change itself with proper nourishment and exercise.

Let me introduce you to Michael Merzenich.

He is a pioneering neuroscientist and a rockstar in the world of brain plasticity. Although he is not the first scientist to demonstrate neuroplasticity but he has been at the forefront of groundbreaking research that's totally reshaped how we understand the brain's ability to adapt and evolve over time.

According to the book, initially, mainstream neuroscience believed the human brain maps were hardwired and could not be changed. Even after Hubel & Wiesel’s discovery, that plasticity exists in infancy, they (including Wiesel) rejected that plasticity continues into adulthood. They only accepted plasticity because infant brain was in the midst of development. However, starting from the end of 1960s, Merzenich’s research continuously showed evidence, proving the opposite.

One of these experiments was to block all sensory input to a brain map and observed how it reacted. And for this experiment he used a monkey’s hand.

Apparently a monkey hand, just like a human hand, has three main nerves: radial, median, and ulnar. In the experiment, Merzenich cut the median nerve, the nerve that conveys sensation from middle of the hand. Two months later, when he checked the brain map of the monkey, he observed, that the area in the brain that used to respond when he stroked the middle of the hand, showed no activity. This result was expected, however, shockingly when he stroked the sides of the monkey’s hand (which conveys sensation with radial and ulnar nerves) the median nerve lit up.

The connections dedicated for the radial and ulnar nerves expanded into the unused median nerve area. Which proved that sensory deprivation led to neural reorganization and increased brain map areas for active nerves. Thus, it was an undeniable proof for brain’s plasticity and the concept of use it or lose it in brain processing.

The study also emphasized our brains’ competitive nature for processing resources. It showed that at any moment in time, there is a turf war going on in our brains. When we are learning something new, when we are scrolling through social media, when we are doing sports etc., we support a side in this war.

Similarly, the more we practice a new skill, the more area it takes over and the better we become. Or, when we stop exercising some of our skills, we don't just forget them; other skills and behaviours we practice more take over their space.

Again, let’s take learning a new language as an example. We use our native languages almost every day. And the more we use it, the more it dominates our linguistic map space. Thus, competitiveness of plasticity, makes it extremely hard for a new language to challenge the space that our mother tongue possesses.

According to Doidge, competitive plasticity in adults also explains why it is difficult to break or “bad habits”.

Competitive plasticity also explains why our bad habits are so difficult to break or "unlearn." Most of us think of the brain as a container and learning as putting something in it. When we try to break a bad habit, we think the solution is to put something new into the container. But when we learn a bad habit, it takes over a brain map, and each time we repeat it, it claims more control of that map and prevents the use of that space for "good" habits. That is why "unlearning" is often a lot harder than learning, and why early childhood education is so important — it's best to get it right early, before the "bad habit" gets a competitive advantage.

Summing u

It got a bit gloomy at the end, right?

But it's not all bad news when it comes to breaking bad habits or learning new things. After all, our brains are adaptable. Even though it can be tough to change, with enough determination and practice, we can make room for new skills.

Just like that proverb, “You are what you eat.” but in this case “You are what you do.” Consistency is key, which is what all those super successful self-help books like Atomic Habits, Willpower Doesn't Work or The Compound Effect tell. In general, these books talk about creating systems that enable you to follow through small but consistent actions over time. And these small actions allow these habits to take over some brain area slowly but consistently.

As I close, I’d like to state that I only scratched the surface. This is a subject that many neuroscientists worked for decades. But if you are interested in more of this subject, I can create a part 2, in the next issue explaining how plasticity enables habit stacking to work, or what kind of effect consistent practice have on your motor control.

As always, feel free to write a comment, text me, email me.

See you guys next time

Quote of the week

Repetition is not repetition. The same action makes you feel something completely different by the end.

-Pina Bausch