Friday, July 9, 2010

A Little Means A Lot

Did you know that our DNA only differs from chimpanzees by 2%. That is right. We share 98% of our DNA with those furry things that swing from trees, eat bananas and screech. So what is it exactly that makes us human and keeps them being chimps?

Scientists, as part of the human genome project, identified specifically which genes are different. Turns out one of them is the regulatory gene that determines how many neurons humans can make and when the process stops.

Human neurons are basically identical those of chimpanzee neurons and even those of a marine snail. Hard to believe, isn’t it? The big difference is in the total number of neurons each ends up making. Humans end up having about 100 billion neurons. Yes, billion. Chimpanzees stop a little earlier so that they have brains about one-third the size of ours.

Each neuron makes thousands of connections. This leads to the possibility of a staggering amount of neural circuits, a ten followed by a million zeros. This huge number allows the human brain to be so complex and to be capable of performing such a vast array of mental functions and behaviors.

This also explains how the brain is capable of massive change through neuroplasticity. Before the discovery and acceptance of neuroplasticity (the ability of the brain to physically change itself and it's function based on a person’s experiences and behaviors) it was pretty much believed the only way the brain could change its structure was through the long, painstakingly slow process of evolution.

Plasticity offers a new way for the brain to change and evolve other than genetic mutation. For example, when a person learns to read, it changes the biological structure of their brain. Reading is taught to the next generation and, subsequently changes their brain and so on.

However, this process of learning not only changes the brain circuits in one area of the brain, but also many modules that are connected to the ones actually used in reading are changed. Plastic change tends to “flow” through the brain. When areas of the brain are linked together in a new way by a new activity, the brain modules involved are changed by the interaction. This creates synergy and a new whole which has greater capabilities than it’s individual parts is formed.

This may explain how our hunter-gatherer brain and more cognitive-cerebral brain work together to make us “civilized.” Becoming civilized is basically a process of learning to restrain or channel brute predatory and dominance instincts into acceptable expressions such as contact sports, board and computer games, art and literature.

The basic instincts are still there, for instance, when a fan yells “Kill him!” at a football game. Yet, when the instinct to stalk prey is linked up to an activity with rules and acceptable behaviors, the neuronal networks are also linked and temper each other.

Civilization is a series of processes where the hunter-gatherer brain teaches itself to rewire itself. Because the plastic brain can always allow brain functions that have come together to separate, regression is always possible. Civilization is always, at most, only one generation deep.


  1. Hi Debbie,
    Oooh goodie, another post with neuroplasticity roots. I'm loving this!

    I think what scares me most about neuroplasticty is thinking about the nature of social media and the internet (two-second bites of everything!). I wonder how this is changing our brain's structure and our ability to maintain attention on one thing for a long time (e.g., writing a book, crafting a painting, or enjoy dinner with family).

    Sorry, I'm a little off topic, but I was just thinking about this as I was reading.

    Profound it is, indeed, to realize that civilization is always one generation deep. I find that to be remarkable.

    Again, great post, Debbie! Sorry I drifted a bit in my comment.

  2. Lori, for some reason it says one comment, but when I go to view it...nothing. Oh well,I can view it in my email.

    You make a very good point. Did you know there is actually marketing geared at taking advantage of neuroplasticity. It is called "neuromarketing" and is really gaining some use. Scary. There are also expensive toys and games now which utilize neurofeedback. Very irresponsible. Through, plasticity, these are actually changing the brainwaves of users without any regard as to whether it is a desired change or not. You better believe that our use of technology is having a plastic effect on the brain. Some good, but mostly not so good.

    All this is for anther blog. I have been filing away the research on it. Certainly does have some huge implications for us as a society.

  3. I always look for blogs with a positive theme and this post definitely fits the bill. While it isn't really talked about (or I haven't come across it), There's a form of neuroplasticity I refer to as making decisions. One looks for and often finds evidence to support one's decisions. That includes deciding to persevere and make a positive life for yourself. Thankfully at least a part of you was "programmed" as a survivor, the depth of which you found out when placed in extraordinary circumstances. That we can mold ourselves and our world view to fit in with such evidence is a form of plasticity that is rarely, if ever, talked about. Thankfully you found and have strength and the plasticity to mold an engaging and productive life.

    May we all find the plasticity necessary to effect and allow positive change in our lives and go beyond merely surviving to thriving.

  4. Mark...thanks for the thought. I like the idea of the act of making decisions being one of neuroplasticity. I agree whole heartedly. That is what I have experienced in my own life. By changing my decision making and perspective and thought processes, it permanently changed my brain over time to become the default and, in turn, changed my life for the better.

    This is the super powers we all possess. Amazingly powerful yet simple stuff which indeed allows anyone to thrive instead of just survive!