Eric Kandel, 77, who shared the 2000 Nobel Prize in medicine, maintains an active lab at Columbia University and mentors younger scientists. "I think I do science better than I did when I was younger," he says. "In science, judgment is so important, and I now have a better understanding of which problems are important and which aren't."
Discoveries of brain functions that hold up, or even improve, through the decades could affect corporate and public policy. As baby boomers age, many are resisting mandatory retirement. Air-traffic controllers in the US are asking federal agencies to reconsider the requirement that they retire at age 55, and the Federal Aviation Administration in January proposed pushing back the mandatory retirement age for commercial pilots, currently at 60.
The emerging neuroscience is on their side. One of the most robust cognitive abilities is semantic memory, which is recollection of facts and figures. "Semantic memory is relatively resistant to the effects of aging," says psychology professor Arthur Kramer of the University of Illinois at Urbana-Champaign. Semantic memory includes vocabulary, which increases with age so reliably (at least in people who continue reading) that a younger person should never challenge a sharp 75-year-old to a crossword puzzle.
Expert knowledge -- information about an occupational or even hobbyist specialty -- resists the effects of aging, too, which is why mumbling "accrued post-retirement liabilities" to an 80-year-old actuary makes his relevant synapses fire as robustly as they did at age 40. Synapses that encode expert knowledge "are written in stone," says neuroscientist John Morrison of the Mount Sinai School of Medicine in New York.
The longevity of expert knowledge and cognitive templates lies behind the finding that air-traffic controllers in their 60s are at least as skilled as those in their 30s. When Kramer and a colleague at the Massachusetts Institute of Technology gave older controllers standard lab tests for reaction speed, memory, attention and the like, they found the usual: Performance declined compared with that of 30-somethings.
But on more fast-paced, complex -- and hence realistic -- tests in which they juggled multiple airliners and handled emergencies, the senior controllers did as well as or better than the young ones. They kept simulated planes safely away from each other, and when they ordered planes to change their altitude, heading or speed to avoid a collision, they used fewer commands than younger ones. It was as if their experience had equipped them with the most efficient algorithm for keeping the planes safely spaced.
That 60-somethings can mentally juggle multiple 747s seems to go against the idea that aging hurts the ability to pay attention. But studies show that selective attention, the ability to focus on something and resist distractions, doesn't decline with age. For controllers, that means they can focus on planes in their sector despite a hubbub of activity in the control tower.
For other seniors, it means no problem keeping eyes and mind on a highway despite flashing road signs or noisy passengers.
The biggest benefit of an older brain is that fewer real-life challenges require deliberate, effortful problem-solving. Where once it took hours of methodical scrutiny to understand a prospectus, for instance, older lawyers and investment bankers can zoom in on crucial sections and fit them into what they already know.
While younger brains solve problems step-by-step, older brains call on cognitive templates, those generic outlines of a problem and a solution that worked before. Yes, older people forget little things, and may have occasional attention lapses, but their cognitive templates are so rich that they more than hold their own. Their brains can keep up even with a diminished supply of blood and oxygen.
As a result, older professionals can readily separate what's important from what's not, a big reason so many of them fire on all cognitive cylinders well past age 65.
"Some things you just need to grind into your system for many years until they become automatic and seemingly effortless," says Naftali Raz of the Institute of Gerontology at Wayne State University in Detroit. "Automatic functions are least sensitive to aging. So, if the decisions are based on knowledge and skill, older folks may have an advantage over younger decision makers just because they have to do less mental heavy lifting."
The benefits that come to the mind and brain with age extend beyond thinking. They also include a greater ability to put yourself in another person's mind, empathizing and understanding his thought processes -- emotional wisdom.