Unbeknownst to many of her peers, 70-year-old Barbara Sainte-Hilaire, MTV's "senior" video game correspondent and star of the blog "Old Grandma Hardcore," is a sensation in video game circles.

A video gamer for three decades, the foul-mouthed granny who favors role-playing games and admittedly stinks at sports titles, says she indulges her habit for about 10 hours a day — significantly more than her 23-year-old grandson, Timothy.

She has an extensive collection of game consoles that would turn many teenaged boys green with envy, and has just finished playing a pair of zombie-slaying titles — "Dead Rising" on Microsoft's (MSFT) Xbox 360 and "Resident Evil" on Nintendo's GameCube.

• Click here to visit FOXNews.com's Video Gaming Center.

"This is my form of relaxation ... I'm not hurting anyone by swearing at our television," said Sainte-Hilaire.

While not all senior citizens possess Sainte-Hilaire's grit and gusto, many are discovering that video games are more than just entertainment.

They reinforce what a variety of scientific studies suggest: that video games can help keep aging brains nimble, encourage social interaction and quicken reaction times.

According to the Entertainment Software Association, 25 percent of U.S. gamers are 50 and older — the same group that is eligible to join the American Association of Retired Persons, whose own Web site (www.aarp.org) offers video games and articles about the benefits derived from playing them.

Pogo.com (www.pogo.com), the online game site of No. 1 game publisher Electronic Arts (ERTS),has been a lifeline in more ways than one for 84-year-old Anna Regan of upstate New York.

Her husband of 55 years died in 1998 and his cousin from Florida sent her a computer. She fired it up, and the rest is history.

"You do meet some odd people and some excellent friends ... I'm addicted," said Regan, who has befriended players from Maine to Texas through the service.

The spirited octogenarian has also met four people in her own area, whom she now counts among her real-life friends.

Regan, who needs a walker because arthritis makes it difficult for her to move around, said her gaming obsession also helped save her life. A dizzy spell caused her to fall from her chair and she was able to send her son a plea for help via instant message.

BRAIN GAMES

Nintendo, known for its kid-focused handheld players and iconic games like "Super Mario," is sponsored a gaming contest in New York this past Saturday to celebrate Grandparents Day, which fell on September 10, the following day.

[According to the Grandma Hardcore blog, Barbara Sainte-Hilaire narrowly won the Nintendo Grandparents Day Brain Age tournament.]

The company's "Brain Age" mind-training game, based on the research of prominent Japanese neuroscientist Dr. Ryuta Kawashima, has made a splash with the international grandparent set.

Its success has spawned a new genre.

MyBrainTrainer.com offers a variety of mental exercises designed to stimulate different parts of the brain.

And Dr. Gary Small, director of UCLA's Center on Aging and author of "The Memory Prescription" and "The Longevity Bible," is teaming with Radica Games (RADA) on an upcoming "brain aerobics" title based on his research.

"I think it's great that the game companies are getting into this," said Small.

He sees the social benefits of gaming but notes that moderation is key, as overdoing it puts seniors at risk of addiction, or joint injuries.

Ralph Swalsky, 66, shrugs off such concerns, saying he plays word games like "BookWorm" whenever he has down time between family and his full-time job.

"I find it's like a crossword puzzle. It keeps you mentally alert," said Swalsky, adding that he has no worries about overdoing it. "I'm more addicted to my grandchildren than to video games."

Indeed, video games are part of the glue that bonds Barbara Sainte-Hilaire to grandson Timothy, who launched the Grandma Hardcore blog at http://oghc.blogspot.com to let friends know what she was up to.

Timothy said his grandmother has always been different in a good way: "Kids would say, 'Something's wrong with your grandma, she's playing Nintendo in her bedroom.'"

"I always thought there was something wrong with their grandparents," he said.