Michael Merzenich, neuroscientist at the University of California, San Francisco, is ruthless as he describes how my 37-year-old brain is going to turn to mush over the years to come.

“You’re going to slowly decline in operating speed,” he says. “Your brain will become noisier and noisier in its processing.” And I will have more and more trouble figuring out exactly what it was I just heard or saw. The villain: age-related cognitive decline, which Merzenich says is a combination of physical changes and something called negative brain plasticity—the cerebral equivalent of what has happened to Arnold Schwarzenegger’s biceps.

A way to combat negative brain plasticity is to train regularly using any of an increasingly wide range of software products designed expressly for the purpose, says Merzenich, who founded Posit Science, which makes one such package.

Cognitive training is growing in popularity as baby boomers age. From 2005 to 2007 the U.S. brain fitness business increased from $100 million to $225 million, according to a report by SharpBrains, a market research company specializing in cognitive health. The growth was driven to a large extent by the success of Nintendo’s Brain Age [see my review of it and two other brain-training games in “Circuit Training”; Scientific American Mind, June/July 2006]. Research does confirm that regular brain exercise is beneficial to elderly people. ACTIVE, a nationwide clinical trial of 2,802 seniors that began in 1998, found that training in specific areas such as “processing speed” ­resulted in improvements that persisted at least
five years.

I recently tried out eight of the latest brain fitness programs, training with each for a week. The programs ranged widely in focus, quality and how fun they were to use. “Like physical exercise equipment, a brain exercise program doesn’t do you any good if you don’t use it,” says Andrew J. Carle, director of the Program in Assisted Living/Senior Housing Administration at George Mason University. And people tend not to use boring equipment. “I remember when NordicTrack was the biggest thing out there. Everyone ran out and bought one, and 90 percent of them ended up as a clothes rack in the back of your bedroom.”

After eight weeks of testing, I have learned some useful things about the software, although I certainly do not feel any smarter. That is not a surprise; I am not old yet, and I do not have cognitive difficulties. “If you have a serious problem,” says Jonas Jendi, CEO of Cogmed America, “the training is worth a lot more.”

There is the question of whether any of these programs are as good as exercising your brain on your own—by playing chess, say, or learning to play a musical instrument. Possibly not, but they are convenient packages that integrate training from many areas.

Is any one of the programs aimed at adults better than the others? Hard to say, and a proper comparative study may never be done. Start with the reviews below, which are organized by program target areas, and then take advantage of the many free trial offers online to see what works best for you. What matters most is whether you enjoy using one and whether it challenges you at the right level. Will you stick with it, or will it become a clothes rack? Your brain health is at stake.

AURAL APPRECIATION

Maker: Posit Science
Name: Brain Fitness Program Classic
For: Seniors
Price: $395 (single user); $495 (two users)
What you get: CD-ROM, instruction manual, headphones
Where to buy: www.positscience.com

Brain Fitness Program Classic improves your ability to recognize sounds as speech and comprehend language. It begins at the most elementary levels—upward and downward frequency swoops common in spoken language—and progresses to syllables, words, sentences and stories. Its effectiveness is backed by scientific trials carried out with children and older adults.

Brain Fitness has a gold-plated user interface, as if you are at an expensive private clinic. The on-screen buttons are huge. The instructions are geared toward users whose response times are a little slower than those of the average middle-age adult—it is pretty clear what you are supposed to do most of the time, although older adults may find the long intro sections more helpful than I did.

During the training period I could notice my hearing acuity improve, in the way you would become able to discern the woodwinds in a Mozart symphony after taking a music appreciation class.

I found the Brain Fitness exercises extremely repetitive, however, and thus about as much fun as running on a treadmill. The designers try to compensate for this lack of novelty with images and Flintstones-like animations, which provide the user with a reward for sticking it out. Waiting to see exactly what bland shenanigans the piano player and his dog would get up to in the next clip kept me motivated sufficiently to finish the week. Merzenich, now 66, says that an improved version of Brain Fitness, out sometime in the spring of 2009, will be more gamelike and entertaining.

NEURO CARDIO

Maker: HappyNeuron, Inc.
Name: Brain Fitness
For: Adults
Price: $89.95 for CD-ROM; $9.95/month or $99.95/year for online membership
What you get: CD-ROM or online membership
Where to buy: CD-ROM at www.amenclinics.com/store in Games section; online membership at www.happyneuron.com

When I signed on to HappyNeuron’s Web site, I was greeted by an electronic “coach” that offered me a program tailored to my needs and a­bility. The coach is like a trainer at a fitness club, says Laura Fay, CEO of HappyNeuron, the U.S. subsidiary of a French company that first released its software in Europe in 2002. Like a coach, “it attempts to make an appropriate challenge,” Fay says. “But it never stretches the goal so far you would injure yourself.”

The coach did not speak, but using HappyNeuron’s Brain Fitness felt like doing cardio with a trainer who has a French accent. The instructions had quirky syntax and occasional Franco spelling, although it is obvious that someone has redesigned the games on the surface to appeal to Americans. Basketball in New York, for one: the object is to rearrange various numbers of balls in different nets. But to a North American sports fan, there is just something wrong about three basketballs sitting one on top of the other in a hoop.

I enjoyed Decipher, in which you have to decode a quote from fake Egyptian hieroglyphs. The sources of the quotes range from Shakespeare to rappers such as The Game. (Useful clue: rappers like to mention their own names a lot.)

Underlying the games, Fay explains, is the theory that there are five distinct domains of cognitive activity: memory, attention, language, visuospatial skills and executive function. The games are designed to stimulate the neural networks in brain regions that have been linked previously to these activities by functional magnetic resonance imaging.

GAMES ON THE GO

Maker: Nintendo
Name: Brain Age2
For: Adults
Price: $19.99 for game; $129.99 for DS console
What you get: Handheld game console and game chip
Where to buy: Many locations, some listed at www.nintendo.com/consumer/retail/retail_retailers.jsp

Playing Nintendo’s Brain Age2 on the Washington, D.C., Red Line train into work one morning, I look up from my console to see my seatmate, a young fellow, intent on his own Nintendo game—one involving a spaceship firing off a lot of missiles. “I’m reviewing this program for a magazine,” I say, hoping he won’t think my mental faculties are actually in poor repair.

I need not have worried. “What’s the ideal brain age, something in your 20s, right?” asks the man, John Benton, 23, a congressional assistant. Benton knows about Brain Age2 because he played the first version when it came out a few years ago. “I always scored pretty old.” This news is good for me because after a week of play, my official brain age is still 52. Benton also has the same beef I did with Nintendo’s character-recognition software: “You write something, and it thinks you wrote something else.”

Brain Age2 is loosely based on the research of Ryuta Kawashima, a neuroscientist at Tohoku University in Japan. Kawashima’s bobbing noggin greets you when you start and carries on one-sided conversations about the time of day or how you are faring. In my case, usually, “Are you tired? Dust yourself off and try again tomorrow.”

You begin with simple games, such as making words out of a rotating circle of letters. The more you play, the more games are unlocked. And the games in Brain Age2 are, for the most part, different from those in the original Brain Age, making it fun to discover what new workouts the game designers cooked up to exercise my prefrontal lobes. It is a good thing that Brain Age2 dangles the incentive of variety if you play regularly, rather than if you improve your scores, because I did not get any better over time.

Maybe part of my problem was that I played only on the train. Brain Age2, played on a handheld controller, would seem to be ideal for train commuters—it lets you skip games you don’t like so you don’t have to be the obnoxious guy apparently barking “Rock, paper, rock, rock, scissors” at his BlackBerry. But the paradox of convenience, I found, is that you need a quiet environment to concentrate. The yammering voices on a crowded subway car—not to mention valid thoughts that you might be missing your stop—are distracting.

SUPERMIND

Maker: Cognifit
Name: MindFit/Cognifit Personal Coach
For: Seniors
Price: $139 for download; $149 for boxed CD-ROM; $19.99/month for online membership
What you get: Download, CD-ROM or online ­membership
Where to buy: www.e-mindfitness.com

MindFit is the brainchild of Shlomo Breznitz, a psychologist at the University of Haifa in Israel and CEO of Cognifit, a company based in Israel with offices in the U.S. and Europe. The ideal training regimen is an hour a week, split into three sessions. “If you can increase your short-term memory by one to two items,” Breznitz says, “it can be revolutionary in everyday life.”

I tested a beta version online called Cognifit Personal Coach. I signed in and immediately the program conducted an exhaustive—and exhausting—assessment. One test worked hand-eye coordination, requiring me to track a ball through a maze. I fear that in Cognifit’s database my name is linked to a high klutz factor, although I do not think it is all my fault. Perhaps the game’s designers had not considered this fact, but ordinary mouse pads are not designed for dragging the mouse around for stretches of six inches or longer. As a result, I failed the test. Thereafter I was subjected to more coordination exercises to remedy my alleged deficiency.

Nevertheless, I genuinely enjoyed some of the games. Supermind, a version of the board game Mastermind in which you deduce a sequence of symbols, was one. In another, I had to find words hidden crossword-style in a giant matrix. I laughed, however, at short words such as “BELL” camouflaged in a giant carpet of letters.

Cognifit Personal Coach differs from the competition, according to Breznitz, in a way that is not apparent to the user. It uses sophisticated artificial intelligence to tabulate the user’s scores in different cognitive dimensions and to carefully calibrate challenges. If the program senses you are reaching a plateau in a particular mode, for instance, it will give you a break for a while. “Then you can come back later and go farther,” Breznitz says. He uses Cognifit himself but says that what really keeps him sharp is working with bright young programmers who ask him tough questions.

CORTEX SPORT

Maker: Lumosity
Name: Lumosity
For: Adults of all ages
Price: $9.95/month; $79.95/year
What you get: Online membership
Where to buy: www.lumosity.com

Lumosity was the program I was most eager to play each day. Its content appears not to be much different from that of its competitors. But its user interface is as well designed as Nintendo’s.

My only complaint was that my daily training was over so quickly. Complete sessions took less than 15 minutes. Can such short stints accomplish anything? On the other hand, I realize, I have been doing stomach crunches for less than 15 minutes a day for the past few months, and my abs are more beach-worthy than they were before I began. Maybe the same holds true for the brain.

Ostensibly, the goal is to increase a quantity called your “lumosity.” This notion rang my quack-alert bell at first, but it is just intended to whet your competitive appetite. Each training session you are assigned four or five games, and you progress through a primer stage to modules covering attention, memory, processing speed and cognitive control. Then you hit extended stages devoted to each of these modes.

Lumosity’s games are standard issue but tarted up in a way that makes them genuinely fun. For example, in an exercise to work visuospatial attention you stare at a four-by-four grid on which cartoon monsters pop up along with vegetable loot. After the graphics disappear, you have to trace a route that avoids the monsters but picks up bonus veggie points. And I loved the bird-watching game, in which pigeons, storks, and so on appear briefly at random locations, and you have to click a camera icon where they were while remembering the letters that flashed in the middle of the screen. The game’s appeal, I confess, owes something to skeet shooting.

BRAIN STRAINER

Maker: MyBrainTrainer
Name: MyBrainTrainer
For: Adults of all ages
Price: $9.95/three months; $29.95/year
What you get: Online membership
Where to buy: www.mybraintrainer.com

If Posit Science’s program felt like an exclusive, if boring, Swiss clinic, MyBrainTrainer felt like the office of one of those doctors who advertise between the true-crime shows on daytime TV.

The homepage is unbelievably cluttered—in effect, giving you your first brain workout. It was a challenge just figuring out how to get to the games. On day three, after the first exercise I was shunted back to what appeared to be the wrong page and spent several minutes clicking on anything that seemed promising. Once I got back to the right page, however, it was unclear whether I was supposed to play each game once or twice.

The games appear to be as valid as any. But I imagine that many users would quickly become discouraged and give up on MyBrainTrainer.

DO THE TWIST

Maker: University of Bern, Switzerland
Name: BrainTwister
For: Seniors or children who have ADHD
Price: $60 (one user); $325 (site license)
What you get: CD-ROM, including manual in PDF form
Where to buy: www.braintwister.unibe.ch

Working memory, the short-term storage that allows you to focus your attention, is crucial for reading comprehension and problem solving. Better working memory correlates with academic and professional success.

A few years ago Martin Buschkuehl was a doctoral student at the University of Bern in Switzerland conducting a study that attempted to increase working memory in older people. His subjects played a suite of brain-training games. “After the study ended, a lot of participants asked if they could have the program to take home,” says Buschkuehl, now a researcher at the University of Michigan at Ann Arbor. Buschkuehl and his Ph.D. supervisor Walter Perrig decided to make a version for use on Macs or PCs, which they called BrainTwister.

BrainTwister is intended for older people who are faced with cognitive decline or for young children who have conditions such as attention-deficit hyperactivity disorder (ADHD). But anyone who would actually benefit from BrainTwister would need a coach or instructor to get started and keep motivated. I had to use all my computer savvy to get the program going, and then I had to delve into the manual to figure out exactly what I was supposed to be doing.

What was it like to use once I got going? Although the games are basic—one of them asks you to remember a series of animals while clicking the right or left mouse button to indicate if each rooster or cow is upside down or right side up—the difficulty accelerates every time you get a test right. BrainTwister quickly had me begging for mercy. I found myself trying different strategies such as mnemonics, chanting a string of the animals’ names or just trusting my caveman instincts to remember what they looked like. I managed six or seven. Buschkuehl says that a girl once reached an “incredible” number of animals, 12 or 13, by humming a tune.

BrainTwister also features a fearsome N-back exercise in which you are presented with a long sequence of images, one at a time, and have to remember whether the image on the screen is the same as that which appeared one, two, three or more places previously. N-back, clearly, is not for wimps. Try the version that combines both audio and vision only if you like to bleed from your ears and eyeballs at the same time.

WORK IT, BABY

Maker: Cogmed America
Name: Working Memory Training
For: Children who have ADHD
Price: Varies; includes practitioner fee
What you get: CD-ROM and coaching assistance
Where to buy: Qualified practices listed at www.cogmed.com/cogmed/articles/en/78.aspx

Like BrainTwister, Cogmed’s Working Memory Training is more work than fun. That doesn’t mean it is unpleasant, though—just that you have to be dedicated. “In the U.S. our target user is an 11-year-old boy with attention issues like ADHD,” says Jonas Jendi, CEO of Cogmed America. Cogmed insists that its product be used only with the help of a licensed coach—a psychologist or physician selected by Cogmed who has undergone a one-day training session. In the U.S. there are 105 such practices.

Working Memory Training consists of eight exercises in a friendly design scheme remi­niscent of a certain Swedish furniture store. ­Ideally you would use the program five times a week for five weeks. It takes about half an hour to get through the exercises, which resemble those from BrainTwister: staring at a matrix of gray buttons, you must remember the order in which they flash orange; you listen to a series of letters or numbers and then ­recite them in reverse order. But there is no N-back, thank God. And although Cogmed’s program is like BrainTwister in that when you get something wrong the exercises get easier again, the decline in difficulty is more cushioned and therefore less discouraging.

Cogmed originated in Sweden. The exercises in Working Memory Training are based on research by Torkel Klingberg of the Karolinska Institute in Stockholm, and their efficacy is well documented.

Note: This article was originally printed with the title, "Brain Trainers".