I was bouncing off the trampoline with my 4-year old daughter some days ago when, to my surprise, she started asking me questions about the human brain!
We have been watching together an old Italian children series about the human body (freely available on Youtube), and one of the episodes talks about the brain.
Perhaps that sparked some curiosity in her.
I was only able to offer some generic answers.
So, I decided to do some research around the subject, because I kind of knew that many advancements have been achieved in this branch of medicine only relatively recently.
The 10% myth
Misattributed to many, including to Albert Einstein, there is a quote you might be familiar with:
“Humans only generally use 10% of their brain”.
Although an alluring idea, it turns out this myth is so wrong “it is almost laughable”, says neurologist Barry Gordon at Johns Hopkins School of Medicine in Baltimore.
“We use virtually every part of the brain, and [most of] the brain is active almost all the time” Gordon adds. “Let’s put it this way: the brain represents three percent of the body’s weight and uses twenty percent of the body’s energy.”
It is unclear how the 10% credence originated.
Some believe the start of it happened in the 1890s when Harvard psychologists William James and Boris Sidis were running some non-intrusive experiments on Sidis’ child prodigy, William Sidis. At the time, the claim that people only use a tiny fraction of their mental potential, sounded credible.
In the last two decades, though, rapid advancements in neuroimaging techniques (known also as brain imaging) have helped scientists to clear all doubts, while also offering unprecedented insights on the workings of our brain.
While it’s true that we have been able to make significant progress in neuroimaging only fairly recently, attempts at imaging the structure and functions of our nervous systems are not a new trend.
The very first chapter of the history of neuroimaging takes place in Italy, with neuroscientist Angelo Mosso designing the “human circulation balance”. This was a non-invasive technique invented to measure the redistribution of blood during emotional and intellectual activity.
William James was aware of Mosso’s work at a high level but the detailed functioning of the ‘balance’ would remain largely unknown until the early 2010s, when Stefano Sandrone picked it up in this volume of academic publication “Brain”.
In the last century, incredible achievements have been accomplished in the field of brain imaging, with technological advancements that go from Computerized Axial Tomography (CAT scan) and Magnetic Resonance Imaging (MRI) of the 1970s, to the more recent functional Magnetic Resonance Imaging (fMRI). These and other techniques’ discoveries are now coupled with the largest ever computing and processing power that enable extraction, collection and analysis of data as well as the ability to create high-resolution brain maps.
What we know now
Thanks to such progress and the research that we have been able to conduct using these technologies, we can now firmly confute the 10% thesis.
Specifically, from all the work and break-throughs of the last two decades, we can derive three key insights.
1. Neuroplasticity
Have you heard of the saying “You can’t teach an old dog new tricks”? Well, it turns out that this is also not true.
The brain has the ability to change its response to intrinsic and extrinsic stimuli by changing shape. Neurons can modify the strength and efficacy of their synaptic transmission (a phenomenon also known as synaptic plasticity).
Plasticity helps the brain recovering from damages that are due to stroke or traumatic injury. The fact that specific neuronal pathways and synapses can be manipulated has tremendous implications for therapeutic interventions.
All the most recent research has repeatedly demonstrated that neuroplasticity is a key feature of the nervous systems across various species, from insects to humans. For humans in particular the malleability of the brain has clear implications in the way we learn.
Perhaps a topic for another post, but neuroplasticity is exactly why learning techniques such as spaced repetition, calibration or desirable difficulty all demonstrably work great.
2. Hebb’s rule
Donald Hebb, the Canadian psychologist best known for his work “The organization of behavior”, is considered the father of neuropsychology and neural networks.
In his 1949 book, Hebb says: “when the axon of a cell A is close enough to excite a B cell and takes part on its activation in a repetitive and persistent way, some type of growth process or metabolic change takes place in one or both cells, so that increases the efficiency of cell A in the activation of B”.
Hebb’s rule might sound confusing at first but it’s perhaps easier to get in its summarized form:
“Neurons that fire together, wire together”
The more we learn the more neural paths we create which change the shape of our brain. So to speak, the more features we can link to a piece of information, the better we are going to remember that information.
Connected to this consideration, there is also a reflection around memory and memorization techniques.
While for quite some time experts and neuroscientists used to compare memory and its role to “a filing cabinet”, we now understand this is quite far from reality.
A better way of describing memory is to associate it to a clay tablet instead: malleable and easy to shape.
In this sense, one of the most interesting developments and research outcomes of the last decades is the understanding that, every time you go back to a memory to “remember it”, that very action changes the memory itself. Mind-blowing.
3. Decision Making
If you know me (or have at least browsed this page) you are already familiar with the book “Thinking fast and slow”.
In that book, Daniel Kahneman describes the work that kept him busy over a few decades together with his colleague Amos Tversky.
The book is a highly recommended read. I won’t attempt to summarize it because I will most certainly do a poor job at it. I will, however, highlight here a couple of takeaways as case in point.
The entire work from Kahneman and Tversky is based on the hypothesis that our way of thinking fluctuates between a System 1 (our quick, automatic thinking mode) and a System 2 (slow and more deliberate).
Often we think we are using System 1 in our reasoning but, in reality, we end up being victims of our own cognitive biases.
In a way, we can say that all Kahneman tried to prove through his empirical research is that most people, including you and me, are indeed dumb. We make impulsive decisions all the time and our behavior is predictably irrational (to quote the work of another expert in the field, Dan Ariely).
Kahneman himself admits that even him, after a life spent anaylsing and researching our brain’s biases, probably only managed to achieve a marginal advantage in his way of reasoning.
This seems at odds with our first two points but it actually isn’t.
Kahneman simply shows that “brain perfection” is not achievable and that the process of consistently running our own mind in debug mode is a hard one.
Conclusive Thoughts
Next time you hear somebody telling you that Einstein once said we only use 10% of our brain abilities… stop, breathe, activate your System 2 and make an effort to explain why that is not true.
Conquering our brain completely seems like a daunting task. But perhaps it’s not even required to notice an improvement in our day-to-day life.
Our scientific researchers have still a long way to go to fully comprehend the intricate workings of our cognitive system, however becoming more aware of the knowledge we currently do have can help us live a better life.
Knowing that we are naturally subject to biases but that we can also actively work to overcome them is a liberating piece of information.
If you are strong-willed, then you can truly set a path for improvement in front of yourself, confident in the knowledge that your brain can support you in achieving the changes you are after.
Also, I now have so much more information I can share with my child!