Kids who play video games have better memory and better control over their motor skills than kids who don’t, according to a new study looking at adolescent brain function.

Video games might not be responsible for those differences — the study can’t say what the causes are — but the findings add to a bigger body of work showing gamers have better performance on some tests of brain function. That lends support to efforts to develop games that can treat cognitive problems.

“This study adds to our growing understanding of the associations between playing video games and brain development,” said Nora Volkow, director of the National Institute on Drug Abuse, in a statement.

The study used data from the Adolescent Brain Cognitive Development (ABCD) study, which launched in 2018 and is tracking brain development in thousands of children in the United States as they grow into adulthood. Participants periodically go through a battery of assessments, including brain imaging, cognitive tasks, mental health screenings, physical health exams, and other tests.

To study video games and cognition, the research team on this new study pulled from the first set of assessments in the ABCD study. It included data on 2,217 children who were nine and 10 years old. The ABCD study asked participants how many hours of video games they played on a typical weekday or weekend day. The research team divided the group into video gamers (kids who played at least 21 hours per week) and non-video gamers (kids who played no video games per week). Kids who only played occasionally weren’t included in the study. Then, the research team looked at the kids’ performance on tests that measure attention, impulse control, and memory.

The video gamers did better on the tests, the study found. They also had differences in brain activity patterns from the non-gamers — they had more activity in brain regions involved with attention and memory when they were performing the tests. Notably, there were no differences between the two groups on measures of mental health (more evidence rebutting widespread concerns that video games are bad for emotional well-being).

This study adds to a large body of work showing differences in the brains of gamers compared with non-gamers and hinting that gamers have an edge on certain types of brain function. Companies are trying to leverage those differences to develop video games that treat cognitive conditions. Akili Interactive, for example, has a prescription video game to treat ADHD, and DeepWell Digital Therapeutics wants to find the therapeutic value in existing games.

But despite all that work, it’s still not clear why there are differences between gamers and non-gamers in this age group. It could be that video games cause the improvements in cognition. It could also be that people who already have better attention for tasks like the ones in this study are more drawn to video games. There are many different types of video games, as well — this new study, for example, didn’t ask what games the gamers played.

“Large gaps in our knowledge on this topic persist,” wrote Kirk Welker, a neuroradiologist at the Mayo Clinic, in a commentary accompanying the study.