Buff up your brain

Exercise improves your health. That's a no-brainer. But do the new brain-fitness programs improve your mental health?

By Robert Burton

Read more: Science, Neurology, Brains, Life, Mind Reader

March 31, 2008 | I was watching PBS the other night when, during one of those interminable pledge breaks, I learned that with a donation I could receive a gift of the "Brain Fitness Program." By doing a few simple mental exercises, I could improve my memory and prevent the mental ravages of aging. "Brain Fitness Program," made by a company with the impressive name Posit Science, is one of the many new brain games that promise to sharpen our gray matter and even stave off symptoms of Alzheimer's disease. In 2007, sales of brain-improvement games totaled $225 million.

It's certainly true that good health practices, physical and mental exercise, and stress reduction are associated with lower rates of mental decline. But do brain fitness programs add any additional specific benefits? The optimistic answer is they might. The realistic answer is that it's hard to know. Despite what the makers of the games claim, there isn't a reasonably foolproof way to measure a program's specific effects on mental performance. In other words, buyer beware.

Let's begin with a look at "Brain Fitness Program." Its Web site explains that as we grow older, the processing speed of our brains slows down. Thus the program is "designed to speed up auditory processing, improve working memory, and encourage the brain to produce more of the chemicals that help it remember." Taken together, "these changes help people feel better equipped to communicate in every setting, making them more confident and more willing to engage in new experiences."

The training consists of six exercises. One involves listening to sounds and determining whether the pitch rises or falls. Originators of the program believe the ability to process these sounds, similar in frequency to human speech, will lead to "quicker thinking, faster responses and fuller understanding." A second exercise promises to "strengthen your brain's ability to perceive and remember subtle differences between similar sounds that are common in English."

Immediately these claims bring us face-to-face with a seldom-discussed problem in contemporary cognitive science -- how to detect changes in mental performance. If you want to study whether a drug lowers the rate of progression of coronary artery disease, you have objective endpoints. You can compare the incidence of laboratory-documented heart attacks or heart-related deaths in a treated group and a non-treated or control group. Ditto for cancer treatment. You can assess cancer-related mortality with and without treatment. Even with the inevitable differences of design and interpretation, studies with clear-cut endpoints are the bedrock of evidence-based medicine.

But measurements of reading skills, ability to navigate mazes, memorize nonsense words, or the speed with which we learn new material -- the kinds of improvements heralded by brain games -- aren't subject to the same kind of independent confirmation. Functional brain imaging can show whether areas of the brain are more or less active than a control group, but cannot accurately predict how these changes will be reflected in ordinary activities of daily life.

At present, the only way a brain fitness program can demonstrate its value is through traditional "neuropsychological testing." But these tests are subjective. They are not an objective counterpart to EKGs, cardiac muscle enzymes, coronary angiogram and death certificate registries. Their validity is solely dependent upon the establishment of "statistical norms" against which a subject's performance is compared.

For example, if 1,000 randomly chosen people read a paragraph in an average of 50 seconds, and you take 55 seconds, that doesn't mean that you have a 10 percent impairment in your reading skills. The test can't tell you the meaning of the five-second difference. Because brain-fitness games rely on the quantification of mental performances to substantiate their claims, we need to understand some of the inherent limits imposed by neuropsychological testing in general.

Neuropsychological testing is good at detecting changes in mental abilities but isn't very good at telling us why these changes are occurring. One major limitation is their relative inability to sort out cognitive changes due to psychological factors. After an in-depth review of neuropsychological tests, the American Academy of Neurology concluded, "Anxiety, depression, psychosis, apathy, and irritability all have an impact on the patient's ability to cooperate with testing and may directly affect cognition." If we're depressed or anxious, or even if we are uninterested, it will be reflected in our test scores.

The converse is also true. If we feel good about taking a test, and yes, even about the men or women administering the test, we will tend to do better. The caveats common to all mental test performances, from IQ tests to SAT scores, are intrinsic to neuropsychological tests, but with a mega-difference. IQ and SAT tests don't suggest why we perform well or poorly. But in order to know whether a "brain therapy" is worthwhile, we need to know whether a test score improvement is a direct and real effect of the therapy.

To put this into everyday perspective, imagine asking Al Gee, a perfectly healthy 65-year-old retiree, to learn a new foreign language. Al randomly picks a computer program in beginning Greek -- "It's Greek to Me" -- and studies the program for a month. His performance, including speed of recognition of individual Greek letters and comprehension of simple phrases, is measured before beginning the program, at the end of the program and periodically over the next five years.

On formal testing, Al's speed of processing new visual symbols (Greek letters) would dramatically improve, as would his Greek-reading ability; a good percentage of this skill would persist months, even years later. None of this is surprising. Even old-timers can learn to play golf or the piano, albeit not as proficiently as when younger, and, once learned, these skills deteriorate relatively slowly over time. Their fMRI scans will show increased activity in regions related to whatever skill they acquired. This measurable improvement is to be expected; by itself, it tells us nothing about the overall "mind enhancement" of acquiring a new skill.

Next page: Understanding the games' placebo effect