The Brain Change Program (eBook)

Chapter 2

Use It or Lose It: Neurons, Pathways, and Habits, Oh My

I was meeting with Harold at his apartment, searching for a place to sit among his many leather working tools. Sadly, our conversation was not about this new hobby he’d picked up while in recovery but about his recent relapse. He refused to meet my gaze and instead stared down at a half-finished belt, twisting it in his hands.

“Were you depressed?” I asked.

“No,” he replied, twisting the belt harder.

“Lonely?”

“No.”

“Were you angry about something?”

“No.”

After going through a litany of possible scenarios that might have emotionally contributed to his relapse, he finally blurted out, “There was no reason! I was feeling fine. I was just walking down the sidewalk past the bar I used to go to. Next thing I knew, I was in my usual seat, drinking my usual poison, and my year and a half of sobriety was gone. I don’t remember opening the door or anything.”

How did Harold turn into a robot that did exactly what he didn’t want to do? To figure this out, we have to look at the brain. The brain has over one hundred billion nerve cells and over one trillion support cells with over a quadrillion connections among them. Until recently, most scientists thought the brain, with all its cells and connections, was a hardwired machine incapable of change. The prevailing thought was that the brain stopped growing around age eighteen and only slowly declined with age. And any lost cells or connections never returned. But beginning in the 1960s and ’70s, various scientific discoveries revealed that the brain physically transforms itself with the activities it performs, rewiring and perfecting its circuitry. I’ll share plenty of examples of this throughout this chapter, so stick with me.

The brain creates new neurons, lays down new circuits, and forms new connections and branches that carry messages to and from other neurons. At the same time, it removes unused connections and prunes dormant or unused neurons, much like the owner of a houseplant will prune dead and dying leaves.

To illustrate this pruning process, imagine a new neuron develops and then heads out into the great wide world of your brain in search of a home where it can attach and grow. Let’s say the new neuron heads over to the area in your brain responsible for kindness. Because you’re already a kind person, the new neuron arrives and sees plenty of kindness neurons hustling and bustling with activity. The new neuron says, “Wow! So much activity! These neurons must need help.” Your new neuron will then connect, grow, and become part of the hard-working crew in this area of the brain. And by gaining a new neuron in this area, your kindness grows and strengthens, and kind responses become even more instinctual.

If, however, the brain belongs to a consistently mean person, the new neuron arriving in the kindness area will find low activity and say, “Oh, the productivity in the kindness area is so slow that this neglected area might be ready to close up shop. No reason to attach here.” The neuron then fails to connect, dissolves, and is reabsorbed by the body.

New neurons are attracted to active, frequently used areas of your brain but do little with inactive, seldomly used areas. But you have the power to alter activity levels in areas of your brain. If the mean person, for example, consciously puts forth the effort to practice kindness, then the kindness area will attract new neurons, and the boost in activity will convince new neurons to attach and become part of the kindness work crew.

Neural Plasticity

Alterations in the brain come from more than adding and removing neurons. Existing neurons can also change. This is, in part, how we transform our brain and the actions associated with it: by exercising choice in our thoughts and behaviors. Neurons become stronger through repeated use and weakened through inattention, so we know that they are malleable. Said in another way, continually stimulating a neuron increases its ability to respond, and repeatedly neglecting a neuron weakens its ability to respond. This ability is called neural plasticity.

Let’s say you want to learn French, so you start learning and practicing the language. As a result, a bunch of your neurons start to develop in relation to French. They start out weak, and you face challenges as you learn, but as French neurons become stronger and faster, you find it easier to use the language. Eventually you’re able to speak French fluently or maybe even dream in French. However, if years go by without practice, you will have probably forgotten a lot of the language when you try to use it again. By neglecting these French neurons, they weaken.

Like muscles, frequently used neurons get stronger, and unused neurons atrophy. They follow the “use it or lose it” concept. A helpful, often-used metaphor that explains how the brain works is sledding down a snowy hill. The hill itself and whatever obstacles may be on it, like trees or bumps, symbolize our genetics, or our starting point. Then, when we sled down the hill, we inevitably leave paths in the snow wherever we choose to steer. If we spend an entire afternoon sledding, then we’ll have worn deep grooves into the snowy paths we steered down most.

Like muscles, frequently used neurons get stronger,
and unused neurons atrophy. They follow the “use
it or lose it” concept.

We lay down mental paths in a similar way. When we choose the same thought or make the same choice over and over again, we create a rut in our mental path that can be tricky to get out of. Then, try as we might to steer another course, we slide into the rut and follow it all the way down the hill.

We can forge new paths, but it’s a challenging undertaking because the old paths are deeper and faster. These paths establish our habits. Repeat a thought or action long enough, and the path becomes an even deeper rut or more “neurologically entrenched.” In this way, mental training is just like sledding down a snowy hill.

Brain Training

Philosopher Alicia Juarrero relates that the effect of neurons strengthening or weakening is a change in probabilities. Learning and training alters your brain structure, increasing or decreasing the likelihood that a group of neurons will fire the same way in similar situations.1 For example, most people run from danger, but rescue personnel intuitively run toward it. They changed their automatic response through training and practice.

In neurological literature, musicians, taxi drivers, and jugglers are other prime examples of training and experience shaping the brain. All of these people show substantial changes to their brain shape and function, and these changes are a product of acquiring on-the-job skills.

Neuroscientist Eleanor Maguire found that certain regions of a taxi driver’s brain were larger depending on how long the person had been driving a taxi.2 That is, a driver with a little experience showed some neural development, but a driver with years of experience showed significantly more development—a big, new brain region. Note that these brain changes do not exist in people who do not drive cabs; they are specific to cab drivers. To put it another way, taxi drivers’ brains are uniquely shaped by the actions they repeatedly perform for their job—memorizing streets, directions, and traffic patterns.

The old static model of the brain might suggest that some people are born with brains uniquely suited to driving taxis, but the reality is that you become what you do. And this doesn’t strictly apply to taxi drivers but also to most other occupations. People’s brains are uniquely shaped by their jobs. You could even say, “Change jobs, change your brain.”

You become what you do.

Turning to musicians, not only are their brains different from non-musicians, but instrument-specific differences also exist among them, highlighting the importance of training.3 Those trained in reading music had structural and functional changes in brain areas responsible for processing sequences, and this training even translated into improved functioning in sequencing tasks outside of the musical domain.4

Musicians also show substantially increased brain activity in regions associated with body movement when listening to musical pieces they know compared to pieces they don’t know,5 and they demonstrate higher brain activity when listening to music they’ve previously practiced.6 This means that practice in a particular area results in a greater ability to recognize and respond to material within that same area in the future.

Another experiment involving musicians revealed that the earlier in life a person begins musical training, the greater their performance potential—greater than those who start later but have the same length of training.7

Finally, turning to jugglers, those who practiced juggling for three months showed structural changes in the brain. But when jugglers refrained from practice for three months, those changes began to disappear.8 This shows that failure to practice results in skill regression—just like our earlier example of losing the ability to speak French by not practicing it.

Taxi drivers, musicians, and jugglers teach us about the relationship between behavior and the brain. If you memorize streets and directions, play an instrument, or...