Brains Benefit from Greater Bandwidth but Less Communication

I've definitely spent some time - and split some attention - at Heroes and Legends in downtown Spokane, Washington.

When I go to a bar to watch a football game on Sunday afternoon – something I do regularly because I’m a Cleveland Browns fan and nowhere but Cleveland do they broadcast the Browns – I often have trouble concentrating on my game. With so many screens showing so many different games, my attention often is drawn elsewhere. In short, when given more options, I tend to use all of them at least a little.

Though my brain is responsible for utilizing all of these options instead of focusing on one, it seems that other parts of my brain are wired oppositely. Some parts actually do a better job of focusing when presented with more options. Specifically, when more connections are available for the brain’s two hemispheres to communicate, they communicate less, and this is a good thing.

The human brain is a staggeringly complex thing that science really hasn’t even begun to understand. Part of the problem is that almost no process occurs in only one section. There is so much cross-communication with different stimulants activating several regions that keeping track of it all is an extremely difficult task.

However, one result that has been confirmed is that the left and right hemispheres are fairly independent, at least when it comes to motor skills. If you’re sitting at your computer right now using the mouse with your right hand and not doing anything else at all, that motion is almost completely controlled by the left half of your brain.

But that doesn’t mean your right half isn’t trying to chime in.

In a new study published in Frontiers in Systems Neuroscience from the University of Michigan’s School of Kinesiology and Institute of Gerontology, researchers have shown that there is cross-communication between the two halves of the brain even when a person isn’t doing a thing, which is a novel result in and of itself. What’s more, the study shows that sometimes one side’s chatter can hinder the performance of the other, even though previous studies have shown that increased activation in both sides is beneficial for many tasks.

Since the participants were all right handed, the right half of the brain should have been silent when playing the game. Here, the older adults showed more activation in the right hemisphere than younger adults.

The communication between the two sides of the brain is controlled by the corpus callosum. Sometimes it acts as a bridge, facilitating the flow of communication. At others, it acts as a barrier, effectively telling one side of the brain to shut the hell up.

As we age, the corpus callosum shrinks, increasing the amount of connectivity in the brain. Some studies have shown that greater activation from both sides of the brain in older adults can help in many situations, such as solving problems or understanding garbled speech. I mean, you have to figure that two halves of a brain is better than one. But this usefulness turns into a hindrance when attempting to control the fine motor functions of just one side of the body.

The research group took two dozen 60-somethings and two dozen 20-somethings, and put them in a pretty simple competition. All they had to do was control a joystick in their right hand in order to move a cursor from the center of a computer screen to a target as soon as it appeared. While each participant played the simple game, an fMRI machine measured the activity of their brain. The results showed that the inability to suppress signals from the wrong side of the brain let the young-un’s beat the geriatrics every single time.

Here’s where the results get tricky. In fact, trying to figure this out let me staring blankly at the computer screen and rereading several passages over and over again.

Apparently there is a difference between connectivity and activation between the brain’s hemispheres, and it’s the increased activation that is a hindrance to simple, single-sided movements. Interestingly, in the older adult test group, those individuals with more connectivity were actually better able to suppress the unnecessary activation from the opposite side of the brain. For some reason, the more channels there are for cross-communication, the easier it is for the brain to not cross-communicate.

Weird, huh?


About bigkingken

A science writer dedicated to proving that the Big Ten - or the Committee on Institutional Cooperation, if you will - is more than athletics.
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