Do crossword puzzles.
That's the advice that appears in almost every news report about preventing Alzheimer's disease. Do crossword puzzles, Sudoku, the daily word jumble — anything to keep your brain active. Mental stimulation supposedly keeps your brain strong the way lifting weights keeps your muscles strong.
But does it really?
The answer is probably, somewhat.
Can scientists prove it? Sort of.
You won't find any rock-solid scientific evidence showing that crossword puzzles specifically will keep your brain healthy, but you'll find plenty of evidence suggesting that mental activity of almost any type, including puzzles, card games, reading, and even plain old conversation, helps to keep the aging brain in good working order.
"I encourage my patients to stay mentally active, but I don't make specific suggestions," said Dr. Steven R. Cohen, a neurologist at Suncoast Neuroscience Associates in St. Petersburg. "I suggest they do something they enjoy, because if they don't enjoy it, it may help the brain, but it won't make them happy. I happen to hate crossword puzzles, but many people love them."
Listen to this
What is it about mental activity that helps the brain?
Any type of mental challenge forces brain cells to make new connections with each other. This process, known as plasticity, enables the brain to retain impressions from the senses, form memories and store the knowledge we acquire. When plasticity becomes sluggish, as it often does in old age, new connections don't form as easily, and new knowledge becomes harder to acquire and retain. Many scientists now believe that Alzheimer's disease results from the exhaustion of brain plasticity.
But muscles that get slack with age respond to exercise, and scientists think that neurons that get sluggish with age respond to mental stimulation.
Michael Merzenich, a professor emeritus at the University of California in San Francisco, has taken that idea to the bank. After distinguishing himself as a neuroscientist through his research into the brain's ability to form new connections, he formed Posit Science Corp., which sells computer games based on his ideas about stimulating brain plasticity.
His Brain Fitness program, for example, introduced in 2004, is designed to build the brain's ability through a variety of exercises, including one that involves recognizing sounds.
What do sounds have to do with memory?
According to Merzenich, the loss of plasticity in the aging brain reduces a person's ability to process information that comes in through the senses. Improve that processing and you strengthen everything about the brain, Merzenich believes, including memory.
"When neuropsychologists think of (memory) deficits, their instinct is to say, 'You can't remember, so let's practice remembering,' " Merzenich says. "That's very wrong-headed. The reason people can't remember is not that they've lost the trick of remembering. It's usually because the quality of information delivered to the memory is degraded. We train the person to more accurately process information."
For example, people who use Brain Fitness listen to electronic sounds that rise or fall. At first it's easy to tell the sounds apart, but gradually the sounds become very brief, and detecting whether they are rising or falling becomes very challenging. Listening closely to these sounds challenges not just hearing, but discrimination, attention, focus and other skills that tend to grow weaker with age. Brain Fitness includes other exercises that involve listening to syllables that sound very similar, and to stories, which demand attention to detail. Merzenich also sells a program called InSight, which contains similar exercises for vision. His programs sell for $295 for one user, or $395 for two (www.posit science.com).
As evidence that his methods work, Merzenich points to a 2006 study that found 93 percent of the elderly participants who used Brain Fitness for several months showed lasting cognitive improvement. Some, he says, improved their memory to the point where they performed as well as people decades younger on tests of memory and other mental abilities.
Give video games a try
Such results, combined with the financial success of Posit, have spawned an array of competitors. In 2005, Nintendo launched Brain Age, also known as Dr. Kawashima's Brain Training. Ryuta Kawashima, a Japanese neuroscientist, wrote a book in 2005 called Train Your Brain: 60 Days to a Better Brain, which caught the eye of Nintendo executives. They developed an electronic version of the book containing puzzles and games. Performance is timed; as users get faster their "brain age" goes down, and Kawashima's face appears on the screen shouting encouragement. Nintendo reportedly has sold 17-million copies of the game at $20 to $30 and recently released a second version. It's played on a handheld game player that costs around $130.
Luminosity is a subscription-based game system ($24.95 for a three-month subscription, or $79.95 a year) launched a year ago on the Internet. It markets its games as recreation rather than therapy. However, the games clearly challenge your short-term memory, concentration and processing speed. (Try a free subscription at www.lumosity.com.)
Happy Neuron (www.happy-neuron.com) features games that test memory, attention, "executive function" and other brain abilities. A free trial is available, and a subscription costs $9.95 a month or $99.95 a year.
Just type "brain games" into Google and you'll find hundreds of sites offering puzzles, brain teasers and other mental challenges, some free and some for a fee.
Keep it fun
But you don't have to pay anything to stimulate your brain. Reading remains a potent challenge to the brain. So does socializing.
Dr. David Bennett, director of the Rush Memory and Aging Project in Chicago, has conducted several studies that show maintaining a strong network of social relationships confers protection against Alzheimer's disease. "Remain cognitively and socially and physically active," he advises. "Remaining active seems to be good for you."
The important point is to stay mentally active somehow.
"The brain is an organ just like any other," says Cohen. "People who exercise get better lung and heart capacity. The brain is no different."
However, whatever you do to keep the brain active, whether it involves games, reading, social activities or a hobby, should be fun, according to Cohen.
"The key thing is enjoyment. Whatever you do should be something you enjoy doing."
Freelance writer Tom Valeo writes about medical and health issues. Write to him in care of the St. Petersburg Times, P.O. Box 1121, St. Petersburg, FL 33731, or e-mail firstname.lastname@example.org.