I believe that gaming can be really an addiction, as I know several children and students doing it. Not everyone develops an aggressive attitude but it is an escape into another world where no one can follow except of the co-players. The velocity is so high that the players must experience when they stop that the world is standing still and that everything is very boring. I think they must see the real world as in still motion and it is the difference of spacetime that causes the development of a schizophrenic condition. Gaming is stepping into an artificial time-machine.

The tools to communicate in reality are missing the power of the games. Also the game industry uses the sophisticated psychological knowledge.

I would suggest using 'empathy' as something to measure in relationship to game playing.  The depersonalization of violence through the use of virtual characters may lead to the reduction of empathy, especially in those 'addicted' to playing violent games.  I agree with Rita that players have entered a virtual world where their own personality adjusts to that world to some degree and carries over to their behavior in the 'real' world.  Monitoring how subjects react to pictures or videos that show pain and suffering as well as joy, for example, may show such differences and may even correlate to characteristics found in prison population.  I think this is a very important area for study.

Two Google Science Fair projects submitted in 2012 looked at specific physical manifestations of First Person Shooter (FPS) play.  One submission looked at whether FPS play (4 hours) changed physical reaction time (i.e., the time it takes the individual to react to a simple visible change on a computer screen), while the other submission looked at whether playing an FPS game (4 hours) altered neuro-muscular control required to bounce a ping pong ball through a hoop (skill task).  The studies found no significant improvement in either reaction time or skilled task success rate.  The first study, however, discovered that FPS players, perhaps because of the need to anticipate ones opponents moves, had a highly and statistically significant increased error rate in reaction time testing (i.e., the subject identified a visual cue before it was offered).  The controls for the second study showed what we all know to be true, practicing a skill task can result in more success.

I suspect that video games can be used to test a wide range of human behavioral characteristics in great detail.  Such tests will, however, require the use of specific controls and limits to appropriately test those behaviors.

sir, if you can relate the addictive property of games through involvement of mental stress associated hypothalamic pituitary adrenal (HPA) axis activation , then salivary cortisol, plasma cortisol , salivary alpha amylase, salivary chromogenin estimation at specific point of intervals i.e, before & after playing game compared to a control subjects playing non violent games. i think addictive property or pleasurable effects of action games in individuals is due to a altered HPA axis activity.

I think the main difference between watching a violent movie and playing a violent game (aside from things like point of view and graphics/realism etc) is the degree of interactivity. Consider what happens at a behavioural level when a person plays a violent first person shooter such as Call of Duty. The character is almost always doing something. Shooting, running, aiming, changing weapons, stabbing, throwing a grenade, taking cover or crouching. Every single one of these actions results from players fingers moving dextrously over the controller and inputting a complicated sequence of buttons. Suffice to say, when playing a violent video game, there is a near constant stream of input. Now consider what is happening at a neural level. Every single one of these hand movements to press the button results in an increase of excitability in the motor cortex. These hand movements and the resultant excitability in the motor cortex are, near instantaneously, causing the actions of the character on screen. It could be said that the activity in the motor cortex is 'synchronised' with the on screen actions. More specifically, it does not matter what these actions are, merely that there is an ‘association’ between the motor activity inputting commands which cause actions within the game. From this perspective, it could be argued than when there is high degree of synchronisation between the motor cortex and the actions on screen, there is a high degree of interactivity, conversely, when there is a low degree of synchronisation in the motor cortex and the actions on screen there is a low degree of interactivity.

Recent advancements in neurophysiology demonstrate the feasibility of using noninvasive brain stimulation known as transcranial alternating current stimulation (TACS) to entrain cortical oscillatory activity such that activity between two regions can be synchronised or desynchronised to produce behaviourally measurable effects. You could in principle simulate interactive violence by using this brain stimulation. Specifically, “phase synchronization between the motor cortex and cortical region associated with aggression at a behaviourally relevant frequency (perhaps in the theta band)” could simulate a high degree of interactive violence. Conversely, phase deynchronisaiton between the motor cortex and a cortical region associated with aggression in the same frequency could simulate a low degree of interactive violence. 

Overall, I think this method, though very speculative, and not not fully thought out, has the potential to be incredibly useful because it can potentially get around the differences in realism of graphics, differences in point of view, physiological arousal ,engagement or even motor movement that most researchers struggle to control for in their studies. To use this "method" to simulate interactivity, a person only needs to be watching a movie/video game footage. Nothing more. The only difference between "interactive" and "less interactive" or " non interactive" is the degree of synchronisation between the two brain regions. You could then administer any behavioural test or some currently available measure to determine the effects of violent video games without having to worry about any of the aforementioned confounds.  

Again, these ideas aren't that well thought out, but I'm curious to see what people here think.

the repercussions of playing so called "violent" video games on social behaviors have to be assessed in regard to the competitive nature of those games rather than their "violent" content.

The increase in aggressivity, impulsivity etc in hardcore gamers would come from the competitive stress they expose themselves to by playing those games on line versus other players.

To assess this hypothesis, I would design a protocol revolving aorund comparing the alteration of behaviors of subjects playing "violent" video games in single player mode (PvE i.e. Player Versus Environment), vs players playing the same game in on online competitive mode only (PvP), versus players playing something like computer chess or a tennis game of sorts in a competitive (PvP) / non competitive (PvE) environement.

I would excpect to see a correlation in behavioral alterations in competitive groups in both violent and non violent games but not in the non competitive groups, therefore demonstrating that long term exposure to competitive gaming is inducing behavioral alterations but not the "violent" nature of the game being played.

Interesting idea Arnaud. You seemed to imply this, but you could potentially compare elite/hardcore gamers (that play in e-sports or various tournaments), to those who play more casually (at home/with friends etc) and might expect a greater degree of behavioural alterations in those who are more competitive?

Here is an afterthought ...

Most gamers, myself included, become immersed within the game being played. For all intents and purposes, the game becomes an alternate, although temporary, reality within which the player performs a specific set of tasks (e.g., kill an opponent, navigate an impossibly complex and lethal maze, etc.).  

Within First Person Shooter (FPS) games, the gamer is often placed in a model "life and death" situation where they must shoot to kill their opponent or be shot dead. The gamer is obviously aware of the lack of true consequence (i.e., when killed the gamer often re-spawns back into the game). Furthermore, the gamer may not identify with team mates and opponents actions, controlled by other gamers, reflects an outcome against another human.  It seems that FPS games are devoid of human empathy.

So here is the question .... Can gamers develop behaviors mimicking Post Traumatic Stress Disorder (PTSD) as a result of game play?  In instances where one gamer is capable of winning every encounter - either as a result of being much more adept at the game, a much higher experience level, or cheating - does the loser adopt behaviors one might expect in stressed individuals?  To what extent can behaviors of violent video game players illuminate behaviors observed on an actual battlefield?  

Testing such questions might be as easy as adding consequence to a game being played (i.e., a tournament where one loses with one player death in an FPS game). 

I've referenced a couple of articles that look at violent/aggressive behavior. I think that if you look at cortisol levels, other measures you may consider are ACTH, late night salivary cortisol, NE, DA, 5HT, DHEA, oxytocin, FSH/LH, 5-alpha-reductase, and genetic variations (ie; COMT, MTHFR, CACNA1C, SERT). Oxytocin and DHEA tend to suppress the cortisol response. Other variations may cause increased aggression. Those are some considerations...though it's a lot for one study. :(

Bohnke, R., Bertsch, K., Kruk, M., & Naumann, E. (20`0). The relationship between basal and acute HPA axis activity and aggressive behavior. Journal of Neural Transmission, 117(5), 629-637.

Gowin, J., Green, C., Alcorn, J., Swann, A., Moeller, F., & Lane, S. (2013). The role of cortisol and psychopathy in the cycle of violence. Phychopharmacology, 227(4), 661-672.

Ivarsson, M. (2014). Psycho-physiological reactions to violent video gaming: Experimental studies of heart rate variability, cortisol, sleep and emotional reactions in teenage boys. [Doctoral Thesis]. Stockholm University, Sweden.

I am not a video game player, but it seems to me there are two important conditions to state out the outset: 1) Is the subject at risk to becoming violent or aggressive, independent of the video gaming? and 2) How long after the video game experience is the subject tested for the effects of playing video games?

I think you will get different results, depending on these two conditions.

Anecdotally,  in my child and adolescent practice  parental concerns raised centre around the child becoming alienated from their families and family values.    Interactions with family members become increasingly more aggressive as does withdrawl from the family life.  The rewards for killing and maiming far outweigh the rewards obtainable from joining in with family meals, playing sport, doing homework or emptying the dishwasher.  Within families, the gamers lack of responsibility for  impulsive lashing out, especially when the rage involves destruction of family property because the gamer has been thawarted, (being asked to stop playing, or only given a specific amount of time) lack of empathy towards other family members and, the inability of the gamer to make the relationship between violent games and poor or no empathy, causes considerable family stress and breakdown.

The instant rewards from dopamine for violence are far easier from the computer than real life. The high emotional arousal and increases in stress hormones resulting from playing are then increased even more when requested  to cease playing. These variables appear to play a significant role, contributing to the lack of empathy, impulsivity and poor decision making.  How one goes about measuring that is out of my area of expertise, parental reports invariably state the child did not exhibit these sorts of behaviours before they became so involved with gaming.  ? genetic vulnerability

It seems to me that in order to properly asses the neuropsychological effects of violent and action video game play we will need to control for a wide variety of variables. To limit such controls, such a study must necessarily include an appropriately narrow definition of the potential neuropsychological effects, violence, action, and game play. Perhaps most important, however, is pre-determining how any such study might be useful clinically.

It seems reasonable to assume that an individuals pursuit of violent and action video game play fills a very basic human need.  It seems that people can become addicted to a variety of games  (e.g., gambling, non-violent and violent computer games, etc.)  like they would to an opiate. The common underlying neurobiochemistry of such addicition might be a good place to begin the study of neuropsychological effects of violent and action game play.