Action video games might harm your brain, Montreal scientists find

A study out of the Université de Montréal says people who play action video games might be harming their brains. 
Researchers found that grey matter deteriorated in the brains of people who spent a lot of time playing games like Call of Duty, Killzone and Borderlands 2. The study also found that grey matter increased when playing games that relied on spatial learning, such as those from the Super Mario series.
The loss of grey matter in question was noticeable in the hippocamp