Seems to me that even if it didn't slow down the "rate" of mental decline, starting from a higher point because of "brain training" for want of a better term would still be good, no?
Yes, but you don't really get to pick your starting point - in the study, cognitive function at age 11 predicted crossword puzzle use and eventual cognitive decline. So if you're fortunate enough to be sharp at age 11 (thanks to your genes, your parents, and your environment), then you're in great shape. But that's not a solution that can be applied to all of us.
That makes the assumption that any kind of brain training raises the bar in a way that mental decline then diminishes. Overall mental degeneration could be a parallel process to cognitive ability that 'blocks' its application. Until all vectors are tested and analysed any assumption is as right or wrong as any other.
