Jogging Your Memory

That's why many scientists are more interested in what we can accomplish naturally, without drugs. "With a reasonable amount of effort, you can improve your memory 30 to 40 percent," says Dr. Barry Gordon, founder of the memory clinic at Johns Hopkins. In the past year, research has shed new light in particular on the benefits of both mental and physical activity. It's been known for a while that aerobic exercise increases levels of a brain chemical called BDNF, which encourages neurons to form new synapses and strengthen existing ones. "I call BDNF brain fertilizer," says Carl Cotman, director of the Institute for Brain Aging and Dementia at UC Irvine. But in the Proceedings of the National Academy of Sciences this year, Small at Columbia showed that exercise in 11 volunteers did even more. Aerobic exercise—an hour a day, four days a week for three months—led to changes on brain scans that seemed to indicate the birth of new neurons in the hippocampus. "My lab members are dusting off their sneakers," he says.

Mental workouts, too, encourage the formation of neural connections. Last month Peter Penzes at Northwestern University published a study showing that brain activity boosts the function of a protein called kalirin-7, whose function had been unclear. Penzes demonstrated that kalirin enlarges and strengthens synapses. By contrast, blocking kalirin causes synapses to shrink. "The old saying was right—use it or lose it," he says.

But the problem with traditional memory exercises has been that practicing one type of task rarely improves performance on others. Working crossword puzzles doesn't help you remember a shopping list. That's why a presentation last month at the Gerontological Society of America seemed so intriguing. In a study of 524 healthy adults ages 65 and over, those who worked an hour a day for eight weeks on a computer-based learning program called Brain Fitness 2.0 from Posit Science showed improvements in a variety of unrelated memory tasks. "The gains were equivalent to turning back the clock 10 years," says lead investigator Elizabeth Zelinski of the University of Southern California. By contrast, participants who were given documentaries to watch showed only marginal improvement (although improvements of any kind are better than declines). Brain Fitness doesn't teach memory tricks, but instead asks users to discriminate between similar sounds and follow auditory commands, in a series of increasingly difficult tests. The ultimate effect is to sharpen the brain's systems of attention—although it's not clear yet how long after training the benefits will last.

But the truth is, there are limits. Even Brad Williams's memory isn't foolproof. In 1993, acting in an amateur theater production, he blanked on the name of one of the play's characters. "You'd think I'd be able to remember it," he says. "It was my own name—Williams." It's so comforting to know he's human, too.

© 2007