I’m just started reading The Shallows: What the Internet is Doing to Our Brains by Nicholas Carr, which was written almost a decade ago. Hey, once something gets on my reading list, it stays there until I at least try to read it. In this case, I’ve stopped reading it about one-fifth of the way through to give myself time to absorb the information, which I will not do if I’m race-reading. Naturally I read more quickly when I’m interested, so unless I pace myself, stuff I’m keen to learn is the stuff I am least likely to retain.

A paradox.

Another paradox is that neuroplasticity has a serious downside. By now, you probably know the current science on neuron regrowth is that is happens continuously throughout life. This is great news if you’re starting a new career. If you become blind, your other senses may expand enough for you to live and work productively. Doctors have even reversed paralysis in certain cases. The process can be slow or seem capricious, and may be less vigorous as we age, but it is real.

Neurons can even be mapped by thought. In one case, a group of non-musicians learned to play a simple tune on the piano, then were divided into two groups. One group practiced the tune on the instrument, while the other spent the same amount of time sitting at the piano and imagining playing the tune. The expected neuronal growth occurred identically for both groups.

Cue the Twilight Zone theme.

Neurons want to fire, so the ones that become unused try to find something to do. Imagine losing a hand. At first, the neurons continue firing, giving you the impression that your hand is still there. Lacking stimulation, they remap to cover something you commonly do, which ideally would be controlling your new prosthetic hand. To achieve that goal, you have to spend a lot of time practicing moving your hand, perhaps even moving it physically using your other hand until the neurons catch on. If instead you get a hook, some of those neurons may control new movements associated with using that, while others may map to your other hand, on which you now rely more. Neurons will be flock to any activity you do regularly.

That’s the problem.

Any habit, good or bad, is reinforced every time you do it, reinforced even to the point of gene selection–yes, neurotransmitters can do that–while unused neural pathways literally disappear as those neurons seek activity. So if I stopped reading every day and instead watched hours of TV, over time I would become disinclined or even unable to read, and would find myself increasingly compelled to stare at the television.

Each time I take a drink of alcohol, I make it more likely that I will drink alcohol. Just sayin’.

This effect is very notable with disease. If you focus on how bad you feel, you will continue to feel bad. This may explain why some people seem to have a lot of ailments that limit their activities, while others rarely give in to anything. The Shallows posits NP as a major factor in chronic depression, OCD, and even tinnitus.

When–if–we swap good habits for bad ones, we hasten intellectual decay. So if there is something you don’t like about your life, don’t dwell on it. Instead, try something new. Your brain will diversify to enable you.