There have been studies by certain groups on the relation on brain activity and violent videogames. 

These supposed studies say that people that play video games's brain show more activity and blood flow to the so called "copy cat" part of the brain. AKA they're more susceptible to  copy what they see happening in the videogames.

This is false, one because the studies produce a nice colored image that looks "official" so the general public who doesnt know any better would agree. 
Two because increased blood flow to a certain area is a VERY broad category, that doesnt translate to any particular behavior.
Three, these studies are all AGENDA driven, meaning they were specifically LOOKING to prove a particular point, Which is NOT how one does research.