The link between computer images of brutality and the real thing may go further than first thought.Violent computer games trigger a mechanism in the brain that makes people more likely to behave aggressively, says a recent US study.
The study, which considered the effects of popular games such as Doom, Mortal Kombat and Grand Theft Auto, which involve brutal killings, high-powered weaponry and street crime, indicates that avid users become desensitized to shocking acts of aggression. Psychologists found that this brain alteration, in turn, appeared to prime regular users of such games to act more violently.
The research, conducted by the University of Missouri-Columbia, stands apart from other studies in that it set out to identify a causal link between violent games and the subsequent behaviour of players.
There have been many previous studies which linked violent games to aggression, but their findings are debated on the basis whether violent games were the cause of aggression, or they just attracted players more prone to violence.
Results of the latest study, reported on the New Scientist website, found that, while participants who played violent video games demonstrated diminished brain responses to images of real-life violence such as gun attacks, they reacted normally to other emotionally disturbing pictures such as those relating to animals and young children.
The study was conducted on 39 experienced gamers and measured brain activity in response to particular images comprised mainly of neutral scenes, but including some violent and negative non-violent scenes.
An EEG provided a reading of the perceived emotional content of an image, which increased when participants were surprised or disturbed by an image. The researchers measured a type of brain activity called the P300 response which reflects the emotional impact of an image.
When the game players were given the opportunity to punish a pretend opponent those with the greatest reduction in P300 meted out the severest punishments.
Subjects with the highest level of experience with violent games were found to have a smaller and delayed response to the violent images. The findings will back up what many have argued over recent years with the growth in games with scenes of graphic violence.
Bruce Bartholow, a psychologist involved in the study told New Scientist: 'As far as I'm aware, this is the first study to show that exposure to violent games has effects on the brain that predict aggressive behaviour.'
Last year's most violent games, as assessed by the US watchdog Family Media Guide, included:
Resident Evil 4: Player is a special forces agent who is sent to rescue the President's kidnapped daughter. Images include a woman pinned to a wall by a pitchfork through her face
50 Cent: Bulletproof Loosely based on the gangster lifestyle of the rapper. Player engages in shootouts and loots the bodies of victims to buy 50 Cent recordings and music videos
Grand Theft Auto: San Andreas Player is a criminal on a mission of murder, theft and destruction. Health is improved by visiting prostitutes, with bonuses for killing them
God of War: A warrior hunts the gods who tricked him into killing his family. Prisoners are burnt alive, victims torn in half