brain improvement game websites

Is the research behind the claims of websites like legit? I understand that the fee to use them (beyond the free games) is like paying for any game, in a way, but are the claims to help legit? Seems like the amount of play would have something to do with any possible result, so they cann’t promise much.

How funny; I came here to ask basically the same question. Anyone?

They don’t according to the study reported by the BBC:

NB: this is just a section of the article.