Researchers find that playing action video games can lead to hippocampal atrophy.
The impact of video games on our health and well-being has often been studied and discussed, and it is still a very controversial topic. According to the Entertainment Software Association, at least one person in 63 percent of households across the United States plays video games for at least 3 hours per week, making gaming one of the most popular leisure activities.
A new study led by researchers from the Department of Psychology at the Université de Montréal, and from the Douglas Institute in Québec, both in Canada, has now found that action video games, specifically, have a direct negative effect on the brain.
Lead study author Dr. Gregory West, an assistant professor at the Université de Montréal, has published the team's findings in the current issue of Molecular Psychiatry.
Action games' effect on brain
The current study stems from two considerations. First, the researchers noted that action video games - which are defined as "first- and third-person shooting games" - are sometimes recommended by specialists to increase the visual attention of children and adults.
Secondly, according to previous research conducted by Dr. West, action video game players employ a particular kind of navigational strategy called "response learning," which is based on forming a navigational "habit" and relying on it.
Response learning is also associated with a decrease in the gray matter of the hippocampus, which is a part of the brain linked to episodic memory and orientation. A low amount of gray matter in this brain area is related to Alzheimer's disease, depression, and post-traumatic stress disorder.
In looking at the effects of action video games on the hippocampus, Dr. West and his colleagues also took into account any links with the striatum, which is a brain area that receives signals from the hippocampus.
The striatum also contains the caudate nucleus, which plays an important role in the formation of habits and procedural memory - that is, the kind of memory that we rely on to know how to walk, swim, or ride a bicycle.
According to existing research, Dr. West and his colleagues note that "the caudate nucleus shares an inverse relationship with the hippocampus."
This means that if we rely too much on habit and procedural memory, we end up underusing the active learning capacities promoted by the hippocampus. This may cause the hippocampus to atrophy, leading to an unhealthy brain structure overall.
"That's why we decided to do a full neuro-imaging study, [...] and what we saw was less gray matter in the hippocampus of habitual players. We then followed that up with two longitudinal studies to establish causality, and we found that it was indeed the gaming that led to changes in the brain."
Dr. Gregory West
Fifty-one male and 46 female gamers were recruited for the current research and were eventually tasked with playing either action video games - which, in this case, were shooter games such as Call of Duty - or 3-D platform video games from the Super Mario series.
Response learners lose gray matter
The participants were first tested to see whether they were "spatial learners," relying on visual clues and landmarks to make their way through a particular environment, or "response learners," relying on acquired habits to navigate. Spatial learners have a more active hippocampus, whereas response learners tend to underuse it.
For this test, the researchers developed a "4 on 8 virtual maze," which is a task that encourages the players to come up with a navigational strategy that links to either the hippocampus or the caudate nucleus.
"The virtual reality task consists of an eight-arm radial maze situated in an enriched environment. The environment contains both distal [far from the player's perspective] and proximal [close to the player's perspective] landmarks: two trees, a rock, and mountains," the researchers explain.
After establishing which players were response learners and which were spatial learners, the researchers asked them to play the action and 3-D platform video games.
It was found that the same amount of time (90 hours) dedicated to gaming had different effects depending on the kind of game that was involved: action games led to hippocampal atrophy, whereas platform games increased the volume of gray matter.
The researchers believe that response learners might be able to increase their gray matter volume by "be[ing] encouraged to use spatial strategies" instead. Dr. West and his colleagues also suggest that game developers might even be able to prevent action games from leading to the atrophy of the hippocampus by changing the games' design.
Action games, they say, "[...] often include an overlaid head-up display which displays an in-game GPS [global positioning system] to direct players to their next location or event," discouraging players from actively employing spatial strategies. Without this, the researchers suggest, the games' negative effect on the brain might be avoided.
Considering these findings, Dr. West and his colleagues advise caution in "prescribing" action video games to young players, as they might end up doing more harm than good. However, the researchers suggest that game training must be adapted to the necessities of the individuals involved.
"For example," they say, "patients with Parkinson's disease who also present with dementia and patients with Alzheimer's disease, schizophrenia, depression, and post-traumatic stress disorder" should not be exposed to action video games, as they already have lower volumes of gray matter.
"In contrast," the researchers add, "patients with Parkinson's disease without dementia do display dysfunction in the basal ganglia, and may benefit from action video game training."