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Defenders of the video game industry say they’re unfairly blamed for the actions of criminals, arguing that movies, books, and TV shows promote just as much violence and aberrant behavior. So what’s different about video games?

Some experts on digital addiction and psychology say games are a training ground for killing people: Their interactive nature pulls you into the gore, they argue, and reward you for being a killing machine.

Special Series

Editor's Note: This is Part Three in a series exploring the connection between video games and violence.

Part One: 'Training simulation:' Mass killers often share obsession with violent video games

Part Two: 'Frag him:' With today's ultraviolent video games, how real is too real?

Part Three: 'Watch this:' How ultraviolent games and films different

Part Four: 'Case study:' Has Grand Theft Auto finally grown up?

“We can’t say video games caused the Newtown shootings,” said Dr. David Greenfield, the director of the Center for Internet and Technology Addiction. “But we can say [Adam Lanza's] actions in killing those kids as well as he did was enhanced.”

Greenfield argues that games train your nervous system to be more efficient at killing. In the human brain, dopamine fires as a physical reward for accomplishing goals such as clearing a room quickly or sniping an enemy from a great distance. Movies, shows and books don't have the same level of reward, he told FoxNews.com.

“How could you make the statement that this has no effect?” he said.

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David Ryan Polgar, a noted tech ethicist, says video games rarely have a strong storyline equal to that in a book or movie. This creates a lack of empathy in the gamer for that character. He says the added realism of next-gen consoles makes this more problematic.

“The prospect of being Travis Bickle from the movie 'Taxi Driver' or Holden Caulfield from 'Catcher in the Rye' as opposed to viewing them would offer the highest level of altered perception and potential increased levels of aggression. That wouldn’t causally lead gamers to violence, but it may blur the lines between reality and the virtual world for an unstable user.”

Chris Ferguson from Stetson University, who has studied the effects of games on psychology, disagrees that playing games can cause violent behavior at all -- or that movies, TV shows, or books can cause violence.

“We find no evidence for either violent video games or television having an impact on youth violence,” Ferguson told FoxNews.com, referencing a study published in April in the "Journal of Youth Adolescence." He said the idea of a first-person shooter being a trainer for killers is absurd and moralistic.

“Your brain also releases dopamine when you read a good book, have sex, enjoy a sunset or a nice meal,” he said. “Playing a videogame is no different in this respect from eating a cupcake. It’s psychobabble to make a perfectly natural process sound much scarier than it actually is.”

'The prospect of being Travis Bickle from 'Taxi Driver' as opposed to viewing him would offer the highest potential increased levels of aggression.'

— Tech ethicist David Ryan Polgar

Ferguson says connecting game use to the Newtown shooting is absurd as well. “How efficient do you need to be when using an AR-15?” he asked.

Microsoft, Ubisoft and several other gamemakers declined to comment but referred to existing research related to game violence and to the game associations.

“Scientists have found there is no connection between playing games and acting violently,” said Dan Hewitt, a spokesman for the Entertainment Software Association.

Hewitt points to reports by the U.S. Secret Service, the U.S. Department of Justice, findings at the Supreme Court, and other research that has determined games do not cause violence. “If you talk to folks in the military, they say games don’t teach you how to shoot a real gun,” he said. “You can play a flight simulator all you want but it doesn’t teach you how to fly a 747.”

Another expert says we need a more balanced understanding. Kevin Roberts, the author of "Cyber Junkie: Escape the Gaming and Internet Trap" and a video-game-addiction counselor, says he works with kids who have violent tendencies, but there is no research to suggest a videogame can cause those reactions more than any other entertainment media.

“Watching violent videos over time desensitizes people to the violence they see in videos, a fact that can literally be measured by brain scans,” he told FoxNews.com. “Playing violent video games arouses certain areas of the brain, leading to a feeling of intensity. But most people who watch violent movies or play violent video games will never turn to violence. However, people at risk for violence might be further induced down this path by both forms of media.”

For gamers thinking of storming the castle in October, there is no clear answer. No current research compares the effects of playing games to the effects of watching other media. What's clear is that more violence is coming.