Here's a new way to bond with your grandson: Instead of telling him to turn off the videogames and get outside, tell him to move over so you can join him.

Videogames don't always deserve the bad rap they get, and many of them are more than just mindless fun. They've got plots so rich and elaborate that they rival those of books and movies -- and because you have to move the action forward yourself, they require plenty of brainpower, too.

That makes them a great way to keep your mind strong, and a new study finds one in particular can help keep yours as sharp as a battle-axe: World of Warcraft.

Seniors in a new study who spent an hour a day lost in this game's world of warriors, warlocks, and druids showed big-time cognitive improvements over just two weeks when compared to seniors who didn't play the game.

Even better, the seniors who scored the lowest on tests given at the start of the study actually enjoyed the biggest cognitive leaps -- so if you've felt your own mind slip a bit, you might want to join the online gaming world sooner rather than later.

One of the reasons WoW is such a brain booster is that it's so involved. It's not just you versus a microchip -- it's a game that places your character into an online world populated by 10 million other human players (even if they don't look quite human on the screen).

Together, you join these other players in a series of quests and battles that help develop your character -- and these tasks often require knowing a lot more than which button will let you swing your sword or wave your wand.

They require serious thought, being engaged with the environment and interacting with others -- basic skills that have shown time and again to be brain boosters no matter how you get them.

If Warcraft doesn't sound like the world for you, then feel free to pick another game -- because at least 20 other studies have found that videogames in general have terrific benefits for the brain.

You can read more about those brain-boosting video game studies on the website of Healthier Talk.

Now you'll have to excuse me. I'm being chased by some trolls, and they don't look happy.