Did you play video games when you were a child? They weren't around until I was in college. But nowadays, kids all over the country are spending a lot of time in front of the TV or computer, playing those games. That's a big change. And with the arrival of

ever-better technologies, video games are increasingly vivid, realistic - and addicting. I've wondered for years whether playing these games influences brain development. I think it might make a kid's brain work faster, able to process more visual information. But I've also wondered if there's a dark side to brain development, induced by the shocking brutality in some of the videos. Now, for the first time, I've found new evidence that violent video games do alter brain functioning.

Researchers at Indiana University in Indianapolis used Magnetic Resonance Imaging (MRI) to map out which parts of the brain are stimulated when kids play different types of video games. One group of adolescents played a violent game called "Medal of Honor," while another group played an equally exciting but non-violent game called "Need for Speed." After 30 minutes, doctors collected the MRI data. The teens playing the non-violent game showed activity in the frontal area of the brain. This is the area associated with concentration, inhibition, and self-control. The teens playing the violent video game showed no activity in the frontal area of the brain. Instead, the game activated their amygdala. This is the "reptilian" brain that's associated with emotional arousal - especially anger.

This study is sobering for a number of reasons. The reptilian, or limbic, brain is the least cerebral and most animal-like part of the brain. It's where your most basic instincts reside. Instincts to do with things like feeding, survival, and procreation. This works well in times of crisis. If you're starving, your reptilian brain will drive you to find food. If someone is chasing you and you're in danger, this part of your brain will put you into "fight or flight" mode. In other words, to protect yourself, you'll either become violent or you'll run for your life.

But this area of your brain has no capacity for logic, reason, or objective decision-making. It has no way to express tolerance, understanding, or love. Now consider that millions of teenagers are over-stimulating this portion of their brain for hours every day. Cause for concern? I think so. Because other research has shown that both repetitive actions and repetitive thoughts hardwire your brain, reinforce whatever actions or thoughts you're practicing, and make it more likely you'll repeat them in the future.

What do I mean by "hardwire"? There are connections between your brain cells that are called dendrites. Repeated activities stimulate dendrites and create neural pathways between different parts of your brain. The more you practice a certain activity, the stronger that neural pathway becomes. These structural changes are the physical mechanisms of learning. And your brain, like the rest of your body, follows the "use it or lose it" rule. Neural pathways that are not being used eventually get "pruned." The Indiana University study, coupled with what we know about conditioning and learning, is not proof that playing video games leads to violence. But it does give us reasonable cause to suspect that children who spend a lot of time firing up their reptilian brains may be more prone to violence - and may be less likely to have self-control. An extreme example of this occurred when authorities discovered a teenage girl who had been locked up in her bedroom for her entire life. Her parents never spoke to her, never touched her - never even acknowledged her. They kept her alive by sliding trays of food under her door. When police arrested the parents and rescued the girl, she was 12 years old. She was unable to communicate with words, as she had never spoken or been spoken to. Psychologists tried to teach her to speak, but she couldn't learn to do it. After running brain scans, they discovered the area of her brain that rules speech had atrophied. Due to lack of use, the neural pathways had collapsed - in this case, irreversibly.

I'm not suggesting that all kids who play violent video games will go nuts and lose their ability to be rational. But the nature of the human brain is clear: Practiced behavior becomes dominant. Functions that are ignored get cut off - sometimes forever. I've never bought my son a video game. Yet they are so popular among his friends, he is still exposed to them. I suspect your children or grandkids are too. And I think there is reason to keep the violent ones away from them as much as you possibly can.

I have one other practical piece of advice for you if your child or grandchild is having a hard time controlling his or her aggression. You might consider a nutritional supplement. Studies show that omega-3s have the power to reduce aggression and violence. For instance, British researchers gave violent prisoners a fish oil supplement along with their regular daily meals. In a matter of days, the prison guards started to notice a change among those prisoners. The results showed that the group taking the supplement had a 37 percent decrease in violent offenses and a 26 percent decrease in overall offenses. Your brain is 60 percent fats, and omega-3 fats are essential for your brain to function properly. Children today suffer from a dramatic omega-3 deficiency. And violent video games just might be making a nutritional deficiency worse.

To give a child a daily teaspoon of cod liver oil as a natural source of omega-3 fats seems to be a good idea. These days, you can find it without the bad taste of the cod liver oil my grandmother used.

[ Note: When you can't spend time in the sun, cod liver oil is the most effective and reliable source of vitamin D.]