Playing action video games may cause depletion of grey matter in the brain, increasing the risk of diseases such as depression, schizophrenia and Alzheimer’s, a study has warned. Researchers from University of Montreal (UdeM) in Canada found that habitual players of action games have less grey matter in their hippocampus, a major part of the brain that is responsible for orientation and for recalling past experience. Previous studies have shown that hippocampus depletion puts a person at risk of developing brain illnesses and diseases ranging from depression to schizophrenia, Post traumatic stress disorder (PTSD) and Alzheimer’s disease.

“Video games have been shown to benefit certain cognitive systems in the brain, mainly related to visual attention and short-term memory,” said Greg West, associate professor at UdeM. “But there is also behavioural evidence that there might be a cost to that, in terms of the impact on the hippocampus,” West added. There is another important part of the brain called the striatum that counterbalances the hippocampus, researchers said. It has an area known as the caudate nucleus that acts as a kind of “autopilot” and “reward system” – getting us home from work, for example, and telling us when it’s time to eat, drink and do other things that keep us alive and happy, they said. Gaming has been shown to stimulate the caudate nucleus more than the hippocampus, 85 per cent of players rely on that part of the brain to navigate their way through a game.

Researchers found that the problem is that the more the people use caudate nucleus, the less they use the hippocampus, and as a result the hippocampus loses cells and atrophies. The team recruited close to 100 people (51 men, 46 women) and got them to come in and play a variety of popular shooter games like Call of Duty, Killzone and Borderlands 2, as well as three-dimensional games from the Super Mario series, for a total of 90 hours. The team scanned the brains of habitual players of action video games and comparing them to non-players, and found that less grey matter in the hippocampus of habitual players. They then followed that up with two studies to establish causality and found that it was indeed the gaming that led to changes in the brain.