From the time of your birth, your parents were bombarding you with messaging. Everything from "Eat your peas" to "Listen up, young lady, this better be the last time you convince your little brother to climb into a laundry basket and then kick that basket down the stairs." (Don't worry, I survived.) Messaging is the very essence of being a parent. And that external messaging is a partial key to who you grow up to be. But what about the internal messaging: how does that happen?
The mass of 200 million interwoven fibers linking your brain's left and right hemisphere is known as your corpus callosum. This high speed communication bridge ensures the two hemispheres work in sync with each other, connecting parts that handle vision, hearing, spacial reasoning, and thought.
So in the case of severe epilepsy, when doctors decide to sever the corpus callosum to keep the epilepsy isolated in one hemisphere, you'd think this would spell doom for the patient. And yet, that is not necessarily the case. Because of the brain's extreme plasticity, the brain of the afflicted patient can create new pathways to carry the messaging even when the bridge is out. The brain's ability to rewire itself is the hallmark of what makes humans such a force to reckon with. (That, and opposable thumbs.) Our brains on a daily basis are constantly rewiring based on a whole host of influences.
Interestingly, these adjustments happen behind the curtain; we are, for the most part, unaware of it. Rewiring tends to follow patterns. It's as if the brain is on the lookout for repeated process and, once detected, says, "Oh, so that's what we're doing now--this must be important." For example, if every day you come home from work, eat dinner and then plant yourself like a slug in front of the TV, your brain's basal ganglia, (home of habit) responds with the new protocol. Before you know it, you've gained 10 pounds as you mindlessly channel surf the barren wasteland of late night television.
Of course, the same is true if you start exercising after dinner every evening. The brain makes little distinction between healthy endeavors and the unhealthy ones. When it finds a pattern, it's like a bear finding a picnic basket: the feast is on.
So what happens if your corpus callosum is stunted, or missing altogether? Well, it can be problematic, according to Claudia Christine Wolf in "The Mystery of the Missed Connection" from this month's Scientific American Mind. It's a daily reality for 1 in 4000 children. Causes include fetal alcohol syndrome, and possibly autism and schizophrenia. Symptoms include problems with verbal or auditory memory, lessened hand-eye coordination, and some developmental delays. On the bright side, the condition is generally nonfatal, and many people with diminished corpus callosums go on to lead normal lives.
Given the brain's changeable nature, you may be wondering if there's a way to boost your corpus callosum. It turns out that children who learn to play a musical instrument before the age of seven show markedly greater neuron fiber connecting their hemospheres. Which is pretty good news if one or both of your parents put the screws to you when you were a kid and made you take piano lessons. According to neuroscientist Gottfried Schlaug in a 2008 Harvard Medical Study, that whole childhood piano business also increases the auditory and motor areas of a budding musician's brain.
My folks were just such screw-wielders, and even though I eventually got kicked out of piano class for being a wise guy and failing to learn my recital piece ("Moon River"), I thank my parents for doing what they could as far as my brain was concerned.
Some of that old wiring must still be hanging around; hardly a day goes by that I don't sit down and bang away at the piano. (Much to the chagrin of my family members, should they get the urge to watch TV, talk on the phone, or carry on a conversation at a normal volume.) I used to think on some level I was simply idling away my time, plunking out my little melodies like auditory doodling. Now I prefer to think of it in terms of brain maintenance. With every tickling of the ivories, my connections grow a little stronger. There's hope yet. Now if I could just train myself to last more than one stanza of "Moon River" without getting too bored to continue...