Do brain training games work? Only at the games themselves.
A few minutes of brain-training games a day makes you generally sharper and holds off decline.
Owen et al. (Nature, 2010) trained 11,430 people over six weeks: they improved at the trained games and at nothing else. Simons et al., reviewing the field for Psychological Science in the Public Interest (2016), found the same absence of transfer across the literature. In 2016 the US Federal Trade Commission fined Lumosity $2 million over claims it could not support.
Check it yourself: doi.org/10.1038/nature09042
You get better at what you practise, so practise the actual thing. For general cognition the evidence points at aerobic exercise and at sleep — both of which are laws in this manual.
Every law on Useful Mind tells you how strong the evidence behind it is. The ones that failed are kept here rather than quietly deleted, because knowing which advice is wrong saves you as much as knowing which is right.
See the ones that held up