In virtually every aspect of today's entertainment world (TV, movies, video games, music) violence is ubiquitous and often glorified.

Suspension of disbelief is entertaining. Sitting passively and watching The Dark Knight Rises or playing Grand Theft Auto is a fun way to relax and forget about real life for a bit. Where’s the harm in that?

The evidence continues to mount that it’s not all good. A study by the Indiana University School of Medicine examined young men and violent media exposure. There were visible alterations in MRI brain scans after only one week of playing a violent video game. In particular, there was a significant decrease in the activation of prefrontal portions of the brain and a greater activation of the amygdala.

A quick lesson: The prefrontal cortex is the so-called “thinking part” of the brain which deals with , , and inhibition while the amygdala is part of the limbic system, the so-called “emotion center” that serves many emotional functions, but can be the trigger for , anger, , and impulsive behavior.

To my knowledge, this is the first prospective study showing actual brain differences in those that play a violent video game versus those who do not.

Of course, just because the brain has changed does not prove causality. If it were all bad, we would be dealing with millions of aggressive, violent young killers, and that's simply not the case.

But the findings are intriguing and beg the question: Does an activation of the limbic system and an inhibition of the prefrontal cortex predispose to violent behavior? This is a relatively easy proposition to test and I suspect we will see more studies soon.

Other interesting studies

The Virginia Tech Research Division showed students several non-violent movies, followed by super-violent movies. Results indicated violent films can increase hostile behavior.

The University of Alabama conducted a similar study and obtained similar results. The study concludes with a caution for parents that immature and/or aggressive children should not have access to violent films.

The Macquarie University Children and Families Research Centre found that children who watch violent movies are more likely to view the world as an unsympathetic, malicious and scary place and that this stimulates aggression.