Add Yahoo as a preferred source to see more of our stories on Google. Brain-training games sell themselves as a way to maintain cognitive function, but the evidence isn't there yet. Eva-Katalin/E+ via ...

Some 2.3 million of U.S. adults over 65 – more than 4% – have a diagnosis of dementia. But even without a diagnosis, a certain amount of cognitive decline is normal as age sets in. And whether it’s ...