To tackle the job, the study’s lead, University of Illinois at Urbana-Champaign psychology professor Daniel Simons, alongside his research team, reviewed the 130 studies most commonly cited by brain-training game companies. The study, titled “Do Brain-Training Exercises Work?”, offered this concise summary of their goals: And of their results:

Scientists Already Suspected As Much

The news isn’t completely unexpected. Scientists have been going back and forth about the benefits of brain games for years, as tech site Gizmodo explains: What’s the impact? In the billions. According to research reported on by the Atlantic’s Ed Yong, brain-training game users “spent $715 million on these games in 2013, and are set to spend $3.38 billion by 2020.” That’s not pocket change. But if the game companies want to keep reeling in the cash, they’ll need to come out with another 130 studies.