“The brain is… the most complex thing we have yet discovered in our universe. It contains hundreds of billions of cells interlinked through trillions of connections. The brain boggles the mind.” – Nobel laureate James D. Watson

“Human beings, by changing the inner attitudes of their minds, can change the outer aspects of their lives.” – Psychologist William James

The brain is a powerful tool for growth. By understanding a bit about biology and how the brain works, we can gain an incredible advantage in achieving our goals. Rather than fighting our natural tendencies we can work with them, so that learning and growing become fun!

Structure of the Brain

Over the past century, scientists have developed a fairly comprehensive understanding of the physical brain and how it functions.

If you make a fist out of both hands and bring your palms and middle knuckles together, that’s about how big your brain is. The total surface area is actually the same size as one to two pages of newspaper,1 but it is wrinkly and folded to allow it to fit in your head (just like a sheet of paper can be made to fit into a much smaller space by folding).

The brain itself is made up of special cells called neurons. Neurons connect to one another through long, thin arms, called axons, to create a vast web of linked cells.

Think of neurons as houses along the frontier that is your brain. If you walk back and forth between two houses for long enough, a path will form. The more you walk, the more defined the path becomes. In this analogy, axons are kind of like the path that connects the two houses.

Let’s say a new neighbor builds another house nearby, so you decide to go visit. Slowly a path forms between the three houses. Eventually you might decide to put down some mulch, or gravel. Maybe someday you pave the path.

Soon, there are a bunch of houses connected by a well maintained street. Then, someone discovers another group of houses nearby, and a road is built between them. Eventually the houses become a city, and the city is connected to other cities with a local highway.

As more and more traffic begins to flow between houses and cities, more infrastructure is built in order to make it easier to travel. A similar process happens in the brain.

Anatomy of a Thought

When you have a thought, an electrical signal passes back and forth between the various neurons responsible for that thought. Because the brain is always trying to become more efficient, every time two cells communicate with one another the brain makes it easier for them to do so in the future by building up the connection between them. Technically, it does this by building a myelin sheath2 around the axon, which facilitates the transmission of the electrical signal.

The more you have a thought, the more the sheath gets built up, and the easier it is for electrical signals to pass between cells. The easier it is for electrical signals to pass, the easier it becomes to have the same thought in the future. As the father of neuropsychology Dr. Donald O. Hebb famously said, “neurons that fire together wire together.”

The process can be thought of as similar to the way that construction crews might add another lane to a well traveled street or highway to make it easier for cars to travel. Every time you have a thought it’s like giving a signal to the construction crews that more thought-traffic is coming, so they prepare by building more infrastructure.

This is essentially how habits are formed. As Michael J Gelb describes in his great book Brain Power, “habits are simply neurological patterns that build up networks of probabilities by forming ‘memory traces’ along the pathways between your brain cells.”


Lucky for us, research has shown that throughout life the connections between neurons are continuously growing and changing. This is referred to as neuroplasticity: “neuro” – from neuron, and “plasticity” – meaning the ability of something to be molded or change. When you practice learning or thinking in new ways, your brain cells automatically rearrange themselves to better serve you in the future.

No matter how old you are or what current mental state you’re in, you can change the structure of your brain and improve the way you think; it just takes practice!

Just as roadways take time to build because crews need rest and new supplies, infrastructure in the brain also takes time to develop. Roads that are built quickly in the physical world will not last long, and it’s the same with your brain. That’s why cramming for a test may work for a day or two, but for long term learning it’s consistency that counts.

Even established infrastructure causing thought-traffic to head in a “bad” direction can be changed over time. When you don’t revisit a thought or memory, the brain takes it as a signal that it is no longer important. Just as a neglected road will eventually fall into disrepair, the connections between neurons are slowly broken down as your brain focuses on building others.

If you’ve got a negative thought pattern you’d like to change, set up roadblocks and detour signs that help point your thought-traffic in a better direction!

Building Your Mental Infrastructure

So the question is: where do you want to make it easier for thought-traffic to flow? Invest in infrastructure to those places. When you spend your time or energy thinking a certain way, your brain lays down infrastructure to make traveling there easier to do in the future.

One of the reasons I do a journal practice every morning and night is to consistently tell my brain where to build more infrastructure, in order to make it easier to have the kind of thoughts I want to have. Focus on the positive, on being grateful, on envisioning your dreams and goals, and that is where your brain will develop. Focus on the past, on regrets, on complaints or negative thoughts, and that is where your mental infrastructure will get built.

It’s an ongoing process, so it’s never to late to start pointing your thought-traffic in a better direction! Again, where do you want to make it easier for traffic to flow?

  1. http://science.howstuffworks.com/life/inside-the-mind/human-brain/brain7.htm []
  2. http://en.wikipedia.org/wiki/Neuron []