December 1, 2007
Rebecca Johnson

One thing scans don’t reveal is intelligence. For that, I turned to Michael Merzenich, PhD. In the world of neuroplasticity, Merzenich is kind of a rock star. He holds 50 patents, is an endowed chair as professor of neuroscience at the University of California, San Francisco, and is the chief scientific officer of Posit Science, the company currently at the forefront of software designed to combat neurological deterioration, a.k.a. aging ( As early as 1979, Merzenich was designing experiments to demonstrate how a monkey’s brain is capable of reassembling itself in response to injury. Twenty years later, head n a handful of others applied those principles to design a computer game to retrain the minds of children who suffer from a certain form of dyslexia.

Merzenich was not surprised to hear that I am no longer as sharp as I once was. “On a statistical average, people start heading south somewhere in their 20s,” he explained. “Your knowledge may grow, but your memory is less precise and your ability to process complex information declines.” This was not what I wanted to hear. Moreover, it made no sense. I know plenty of people in their 20s. They are idiots.

“Twenty-year-olds may seem stupid,” Merzenich said, laughing. “But they are processing information more quickly and can interpret it more accurately than you or I. Intelligence and stupidity are complex issues.” By the time we move into adulthood, he explained, the skills we will use for the rest of our lives have pretty much been acquired. What we call adult wisdom is mostly pattern recognition–having been there and done that, the brain can fly through the available options more efficiently and (theoretically) with a better outcome.

The problem is, wisdom makes us lazy. We stop challenging ourselves as the brain ages partly because the challenge itself gets harder. This, as Norman Doidge explained it, is the paradox of plasticity. “It’s like a mountain covered with snow,” he said. “When you are at the top, there are a lot of different paths you can take down, but once you take a path, the second time down it becomes easier to take the same, or a very similar , path, Eventually, it becomes a rut. The plasticity that allows us to do new things is the same one that makes us develop the ruts.”

Getting out of a rut requires consistent and progressive challenges over a long period of time. People think that means redoubling your efforts at finishing the Sunday crossword puzzle, but it’s not that simple. “This has been poorly understood by the public,” Merzenich lamented. “So much of what is being done in this field is bullshit ” in some cases by earnest people and in some cases by charlatans. We are at the beginning of a revolution, but it’s a long process. How do you get a 30-year-old to understand that starting to do the brain stuff now will make a difference when they do get old?”

Just as you nee to exercise in order to keep your body fit, Merzenich maintains that the brain also needs exercise. Being a more complex organ, it needs more complex exercise, which is generally beyond the reach of the average person. Merzenich’s company isn’t the only one pushing computer-based exercise to stave off cognitive decline-type “brain fitness” into Google and the choices are overwhelming–but it’s got the most science behind it. Just this year, scientists from the University of Southern California and the Mayo Clinic completed a multimillion dollar study measuring the effect of Posit Science’s program on more than 500 participants ranging in age from 65 to 90, the results of which will be published in the next year. Previous studies have shown that after people completed the 40-hour program–one hour, five days a week, for eight weeks–they could turn the clock back on cognitive function (as measured by speed and accuracy on the test) by more than ten years.

Merzenich is right that the average 30-40 year old is unlikely to spend an hour a day at the computer struggling to distinguish whether a sound swoop is going up or down (a lot harder than you might think) or whether the computer just said “Toe,” “Doe,” “Goo,” or “Gah.” I spent $400 on his software and clocked about five of the recommended 40 hours but did not manage to change my initial score of–average,–but having done so badly on my brain scan a few weeks earlier, I was delighted to find myself deemed–age appropriate.”

Simply understanding the principle of neuroplasticity is enough to change your life. It did mine. Growing up, I was taught that people should do what comes naturally to them. Math was a struggle for me, so I concentrated on English. I enjoyed piano lessons but played so badly I dropped them out of embarrassment. It’s human nature to gravitate toward you are good at, but looking back, I wish I had stayed with what was hard.