Studies show that mental activities like card games, and their social aspects, may reduce the risk of dementia. “It’s what keeps us going,” says Georgia Scott, 99, center, at her retirement community.

By BENEDICT CAREY


LAGUNA WOODS, California - The ladies in the card room are playing bridge, and at their age the game is no hobby. It is a way of life, a daily comfort and challenge.

“It’s what keeps us going,” said Georgia Scott, 99. “It’s where our closest friends are.”

In recent years scientists have become intensely interested in what could be called a super memory club - the fewer than one in 200 of us who, like Ms. Scott, have lived past 90 without a trace of dementia. It is a group that, for the first time, is large enough to provide a glimpse into the lucid brain at the furthest reach of human life, and to help researchers figure out what, exactly, is essential in preserving mental sharpness to the end.

“These are the most successful agers on earth, and they’re only just beginning to teach us what’s important, in their genes, in their routines, in their lives,” said Dr.Claudia Kawas, a neurologist at the University of California, Irvine. “We think, for example, that it’s very important to use your brain, to keep challenging your mind, but all mental activities may not be equal. We’re seeing some evidence that a social component may be crucial.”

Laguna Woods, a retirement community of 20,000 south of Los Angeles, is at the center of the world’s largest decades-long study of health and mental acuity in the elderly. Begun by University of Southern California researchers in 1981 and called the 90+ Study, it has included more than 14,000 people aged 65 and older, and more than 1,000 aged 90 or older.

The results of this study are starting to alter the way scientists understand the aging brain. The evidence suggests that people who spend long stretches of their days, three hours and more, engrossed in some mental activities like cards may be at reduced risk of developing dementia. Researchers are trying to separate cause from effect: Are they active because they are sharp, or sharp because they are active?

The researchers have also demonstrated that the percentage of people with dementia after 90 does not plateau or taper off, as some experts had suspected. It continues to increase, so that for the one in 600 people who make it to 95, nearly 40 percent of the men and 60 percent of the women qualify for a diagnosis of dementia.

At the same time, findings from this and other continuing studies of the very old have provided hints that some genes may help people remain lucid even with brains that show all the biological ravages of Alzheimer’s disease.

To move into the gated village of Laguna Woods, people must not need full-time care. Their minds are sharp when they arrive, whether they are 65 or 95.

The very old who live here diagnose each other, based on careful observation. And they have learned to distinguish among different kinds of memory loss, which are manageable and which ominous.

Here at Laguna Woods, many residents make such delicate calculations in one place: the bridge table.

Contract bridge requires a strong memory. It involves four players, paired off, and each player must read his or her partner’s strategy by closely following what is played. Good players remember every card played and its significance for the team. Forget a card, or fall behind, and it can cost the team - and the social connection - dearly.

“When a partner starts to slip, you can’t trust them,” said Julie Davis, 89, a regular player living in Laguna Woods. “That’s what it comes down to. It’s terrible to say it that way, and worse to watch it happen. But other players get very annoyed.”

Most regular players at Laguna Woods know of at least one player who, embarrassed by lapses, left their regular game. “A friend of mine, a very good player, when she thought she couldn’t keep up, she automatically dropped out,” Ruth Cummins, 92, said. “That’s usually what happens.”

In this world, as in high school, it is all but impossible to take back an invitation to the party. Some players decide to break up their game, at least for a time, only to reform it with another player. Or, they might suggest that a player drop down a level, from a serious game to a more casual one. No player can stand to hear that. Every day in card rooms around the world, some of them will.

“You don’t play with them, period,” Ms.Cummins said. “You’re not cruel. You’re just busy.”

The rhythm of bidding and taking tricks, the easy conversation between hands - after almost a century, even for the luckiest in the genetic lottery, it finally ends.

“People stop playing,” said Norma Koskoff, a regular player here, “and very often when they stop playing, they don’t live much longer.”