Neuroplasticity - we have a brain that keeps changing
Neuroplasticity is probably the single most important concept in all of neuroscience.
It simply means that your brain can, and in fact, is always changing. Since your brain is the centre of everything that you think, feel, and do in life, when your brain changes, so do we, the lives we lead.
As you will see in the examples to come, neuroplasticity is today an indisputable fact. But up till only about 25-30 years, we believed that after puberty, the brain can only decline. But we now know conclusively (after years of brutal scientific fighting), that even in adulthood, our brains can change remarkably - we are not limited by age.
I have broken neuroplasticity into 2 parts:
Here, in part 1, we will cover what and how neuroplasticity takes place, and what this means for our learning and our lives.
Cool let's get started.
How does neuroplasticity occur?
Our brains are made up of cells called neurons, up to a hundred billion of them. In turn, each neuron can be connected to ten thousand other neurons.
You can think of each neuron as containing a little signal or a little piece of information. Everything that happens in our lives, every thought, every recollection, every reaction, every skill performed, every habit lived, every emotion felt occurs because (a group of) neurons are activated. For simpler things, like remembering where the "r" is on the keyboard, it only requires a few neurons to activate.
For more complex assessments, like learning about neuroplasticity, more neurons need to be activated, and crucially at the same time - some store the new information coming, while others link the information to existing knowledge. For really complex assignments, like giving a speech on neuroplasticity, even more neurons need to be activated and work in sync - all the neurons that store your knowledge on neuroplasticity, plus neurons involved in organising information, in speaking, in remembering what works in previous speeches. One network of neurons ned to activate another and another, and collectively, they need to activate at the same time for this complex assignment to work.
An analogy makes this clearer. There are many people in each society - these are our neurons.
If we want a small change in society, say we want to clean up around the house, then only a few people in the family are involved.
But what if we want to clean up the neighbourhood? This would require more people to be involved, and different types of people. Some who had the initiative to want to start the action, others to persuade more people to join in. Finally, everyone needs to participate in the clean-up together - it won't work if someone wants to start an action, and then it takes 3 years to get the word out, and then 4 years later some folks agree.
What about an even larger goal? We want to enact a law to fine people who litter. Now, not only do people need to be involved but also institutions where groups of people with defined roles - like social groups, the lawmakers, the police, and the media to let everyone know that a new law has been introduced. These institutions are like different brain regions or large, established neural networks in our brain, involving many interconnected neurons.
Here is the time to introduce the golden adage of the workings of our brain - neurons that fire together, wire together.
Neuroplasticity is the process where the connections between neurons can be changed, allowing more neurons to wire together and fire together, that can effect bigger and more lasting changes.
How does this happen? At a few different levels:
The first is chemical. The neurons in your brain "talk and listen" to each other by transferring chemicals. So more chemicals can be produced, or the same amount of chemicals can be better received, which causes neurons to be able to influence another more effectively. Back to our analogy, this is akin to better communication between members of the family, so that everyone agrees and takes part in cleaning the house. But it's important to note that at this level, changes are small and not permanent. Only the house is cleaned. More importantly, if all that is improrved is communication, then the process must start again the next time the house has to be cleaned.
When you are first introduced to a concept which you are interested enough to pay attenton to, there is greater chemical activity between some neurons, trying to code this new information. You might be come more sensitive to this concept in the future, but if you are going to hear this information just once, you're not likely to learn much from it.
The second level is structural. This happens where existing neurons form new connections with neurons they previously didn't have a connection with. This interaction creates new meaning and new developments that were prevously lacking. Back to our analogy. Cleaning up the neighbourhood means that you have to work together with people you did not know previously. And even though people didn't know each other before, they establish something new, they get to know each other better as they clean up the neighbourhood, and they share a common experience together, which becomes a memory.
Compared to level 1, we can see that structural changes require more time, more work, and different types of work to develop. It's not possible to just gather a few people (or a few neurons) and speak to them. Just like it takes time and work for community of people to come together to tackle a bigger problems, a community of neurons, each responsible for one part of the body of knowledge, only forms after we put in time and work to read through, learn, watch videos and test ourselves on the topic.
Some of these networks become so large, we can even observe them changing physically - they litrally get bigger. A great example are London cab drivers, who had to memorise a map of London to get their cab driver license. In brain scans, we see that the brain regions related to memory and spatial judgement grew larger. Similarly, if you were to start learning say braille, the part of your brain devoted to sensory inputs will enlarge. Finally, quite remarkably, we can actually grow new neurons, in a process called neurogenesis - this was again heavily disputed in the past, but is now an indisputable fact. Find out more about neurogenesis here.
Interestingly, just as neuroplasiticty allows our neurons to form new bonds, it can also cause old bonds to slowly weaken and die off. Being open to changes works both ways. After getting together to clean up the neigbourhood, if there is no further contact, people will slowly lose touch with each other. If we learn about neuroplasticity just once, and never revisit again, 20-30 years down the road and we asked to recall what we have learnt, we realise there are gaps in what we remember. Some links between neurons or community of neurons have expired.
The third level of plasticity occurs at the functional level. As you use a brain region it becomes more and more excitable and easy to use again. And as your brain has these areas that increase their excitability the brain shifts how and when they are activated. Again, back to our analogy, what if we wanted to enact a major law that affects everyone. This would require different groups to agree with this notion, push for it, and as more and more momentum builds, eventually a law can be passed.
We can see this in the formulation of habits. When you first start playing the piano or riding a bicycle, different parts of your brain is trying to figure out how things work. In fact, in the early stages of learning a new skill, many parts of our brain are invovled. But over time, this becoems easier and easier. Our neurons become very attuned to performing the skill, until it reaches a point where it becomes a habit, we can perform the skill automatically without neding to run throught the steps. As you move from learning to making it a habit, the prts of your brain involved also changes, from many parts at the start, to eventually shifting to just one part - your basal ganglia.
And we also have a negative example. A soldier involved in war finds himself facing traumatic events daily. The amgydala - the part of the brain that regulates fear, anger, anxiety, and aggression gets more and more active (and expands) after each traumatic event. And even when the soldier retuns to normal life, he suffers from post-traumatic stress disorder. He is anxious and edgy, even when there is no threat. He struggles to get back to normal life.
But the most obvious examples of functional difference comes from those who suffer from brain injury or a disorder or a disability, and are able to rewire their brains (most of the time partially) to return to some form of normalcy. This has a stronger medical element, which falls outside of what were interested in. For good reading on this, consider Norman Doidge's "The Brain that changes itself".
Great! So what does all this neuroplasticity mean for me?
Our brains are always learning throughout our lives from our experience and our behaviour. And it reconfigures itself to better perform what is repeatedly emphasised from our choices. And this is a tremendusly empowering realisation.
Your brain is different from when you first started reading this article (at a very miniscule level). Your brain changes between the time you get up to the time you go to bed. There are limits to how much your brain can change, but most of us never come close to these limits. We can always learn new skills, change past habits, reinvent and become better versions of ourselves. And we can do so throughout our lives, even into our senior years.
But this learning is neutral. The reconfiguration does not distinguish between what is good or bad for us, merely what is emphasised, especially through repetition.
If we feel anxious over everything in our lives, we get better and better at feeling anxious. Conversely, if we emphasise to ourselves to examine our anxieties and not over-react to anything that's not perfect, we adapt to becoming less edgy.
The more time we spend learning new knowledge or new skills, our brains reconfigure to get better at it. But this new skill could be learning to skydive, learning a new language, or learning to check out phones every 5 minutes to distract ourseleves from present reality.
This is the nature of a plastic brain.
The graphc appended below is quite a good summary of neuroplasticity from the National Institute for the Clinical Application of Behavioral Medicine. Click to expand.