The article is crap but referring to the sample size without considering the baseline success rate is misleading. If, say, the task were to be creating a billion dollar company, and the treated group had even one success, then that would be quite serious evidence for an effect, just because of how rare success is.
As is usus, consider such data to be within expected parameters unless mentioned.
NPR reports on a study giving volprioc acid to adults and training them on pitch (singing):
Brain plasticity is useful for a whole lot more than learning pitch. As the article notes it would be invaluable for training one's ear to pick up sounds of foreign languages, but also it seems reasonable to this commentator that high levels of plasticity during rationality training or other forms of self-development would result in more transformative results.