The author does mention this under '2. Challenge Yourself': > I'm going to shatter some of that stuff you've previously heard about brain training games. Here

The author does mention this under '2. Challenge Yourself': > I'm going to shatter some of that stuff you've previously heard about brain training games. Here goes: They don't work. Individual brain training games don't make you smarter—they make you more proficient at the brain training games.