(CN) — Playing action video games can reduce gray matter in a major part of the brain, increasing the risk of developing brain illnesses and diseases, according to a study published Monday in the journal Molecular Psychiatry.
While some neuroscientists have encouraged patients to play video games as a way to improve mental functioning, the new research finds that playing action games leads to decreases in gray matter in the hippocampus, a seahorse-shaped brain area involved in memory of experiences — episodic memory — and orientation, or spatial memory.
“Video games have been shown to benefit certain cognitive systems in the brain, mainly related to visual attention and short-term memory,” said lead author Greg West, an associate professor of psychology at the Université de Montreal in Canada. “But there is also behavioral evidence that there might be a cost to that, in terms of the impact on the hippocampus.”
Gray matter depletion in the hippocampus increases a person’s risk of developing brain illnesses and diseases such as schizophrenia, depression, PTSD and Alzheimer’s disease.
The report finds that playing action games leads to an imbalance between the hippocampus and an area in the striatum called the caudate nucleus, which serves as a kind of “autopilot” and “reward system.”
Gaming stimulates the caudate nucleus more than the hippocampus, which leads to the latter losing cells and atrophying, according to the study. About 85 percent of players rely on the caudate nucleus for in-game navigation.
To test the effects of video games on the human brain, the team recruited 51 men and 46 women at the Université de Montreal and had them play a variety of popular shooter games, including “Call of Duty,” “Borderlands 2,” and “Killzone,” in addition to 3D games from the “Super Mario” series. Each participant played for a total of 90 hours.
Before playing the games, the participants had to navigate through a “4-on-8” virtual maze on their computer, which allowed the researchers to determine whether they were spatial learners, who favored the hippocampus, or response learners, who relied on the reward system.
The participants started out in a virtual central hub, from which they had to navigate down four identical-looking paths and capture specific objects. After finding the target objects, the gates were removed and they went down the four other paths.
The team found that spatial learners oriented themselves with the help of landmarks in the background, which included a rock, mountains and two trees.
Response learners ignored the landmarks and focused on memorizing the sequence of a series of right and left turns from the starting position.
After establishing their learning strategy, the participants began playing the games.
Playing action games for 90 hours led to hippocampal atrophy in response learners.
Playing 3D games for the same amount of time, however, increased gray matter in the hippocampal memory system of all participants.
The team recommends that action-game manufacturers adjust in-game designs to stimulate spatial learning.
As is, “players can easily choose to navigate with a response-route-following strategy without relying on the relationships between landmarks, fundamental to the spatial strategy,” the researchers wrote.
“Action video games designed without in-game GPS, or (without) wayfinding routes overlaid on the game’s display for the player to follow, could better encourage spatial learning during action video game playing.”