But it's not just a game -- it's also therapy. National experts in aging say the use of mental exercises to maintain or improve memory in older people could help change the model of aging from survival to success.
The specific goal for the various kinds of brain training is to increase the connections among nerve cells in your brain.
"The theory is that the more connections you start out with, the more you can lose before Alzheimer's starts affecting your day-to-day life," said Dr. Murali Doraiswamy, a Duke psychiatrist who studies Alzheimer's disease.
And it's almost never too early to start the process, Doraiswamy said: "Sometimes in your 40s and 50s, the Alzheimer's process starts kicking in."
At Abbotswood, the 19 residents who gathered last week for class with elder-care instructor Martha Grove Hipskind seemed as interested in having a good time as in protecting themselves from memory loss.
"We think it's fun; that's why we come," said Esther Harlan, 90.
In an activity room at the 124-resident facility, people in the class fired off answers to Hipskind's puzzles, trivia questions and word play.
"[Blank]... makes the heart grow fonder," the instructor said, looking for the first part of the saying.
"Absence!" most of the class said. "Absence," Lib Richie, who has been physically slowed by Parkinson's, chimed in softly from her seat in the back of the class. In rapid succession, members of the group spelled words backward, identified famous women from one-sentence clues and came up with words containing "us" based on definitions from Hipskind.
"A delicious, chilled, whipped chocolate dessert!' she said.
"Mousse!" they chorused.
"Your aunt's or uncle's children!" she said.
"Cousins!" they said.
It's all really about the search, Hipskind said after class.
"It's like getting a hard drive to spin," she said. "Whether they know the information or not, they are still looking."
But the benefits of mental aerobics still haven't been put to the most reliable test: No scientific trial has looked at people who go through the exercises and contrasted their mental acuity with people who have not.
"The information that people have looked at is the frequency with which people do mentally stimulating activity," said Marilyn Albert, co-director of the Alzheimer's Disease Research Center at Johns Hopkins University. "How often do they read books? Do they play bridge? Do crossword puzzles?"
The question of what most influences memory retention is complex, Albert said. For instance, the conviviality of the Abbotswood group goes along with the idea that social interaction can also act to ward off memory loss. There are no best practices for memory training that are based on randomized trials, which are viewed as the most conclusive, Albert said.
"People would love that, and we just don't have it," she said. "There's a lot of desire to have clinical trials and find out how much mental and physical activity is good for people, but right now we are just trying to extrapolate from the observed studies."
It's possible, and in some cases easier, to exercise the brain at home, Doraiswamy said.
"The two types of activity that seem to produce the biggest brain boost are reading and performing math -- if people just want day-to-day things they can do," he said. "They produce very robust increases in [the brain's] blood supply."
Commercially marketed programs such as Nintendo's Brain Age can be of value for seniors who have computers, Doriswaimy said. Woodland Terrace, a sister facility to Abbotswood, has used the brain training software made by PositScience, staffer Connie Miller said.
A National Institutes of Health committee that looked at existing studies suggested early this year that researchers should "pursue the avenue of brain health maintenance with as much vigor as is brought to the quest to understand the pathophysiology of brain disease."
