matically wane either. One example is
higher-order decision making such as
choosing the best investments. Older
people do as well as younger ones on
tests that measure this function—as
long as they aren’t rushed.
And that’s the catch. Some brain
functions tend to decline with age,
and speed is one of them. The likely
reasons are loss of neural connections,
blockages of blood supply, and decreases in nerve-signaling chemicals.
Memory can also diminish with age,
though only certain types. Learned
skills such as driving are wired so
firmly that they typically do not decline unless you have a disease such
as Alzheimer’s. Memory for events
(called explicit memory) is a bit more
vulnerable, although episodes that really made an impression, such as meeting your spouse, are generally secure.
If your memory is suffering, it’s
most likely your short-term memory.
This ability—which includes “
working memory,” where events are held
before being filed for the long term—
usually peaks by the early 30s. That’s
why memorizing complex new information, such as a foreign language, can
get harder as you get older .
So how do you keep your brain at its
best? By growing new brain cells, for
starters. Long thought impossible, this
turns out to be relatively routine in lab
animals and, thus, maybe in humans.
Scientists suspect that certain lifestyle
habits can spark the cells’ growth.
In 1998, Fred Gage, Ph.D., and his
colleagues at the Salk Institute for
Biological Studies in La Jolla, California, showed that the memory centers
of adult human brains can grow new
cells. Since then, studies by Gage and
others have suggested that the more
physical and mental exercise you get,
the more brain cells you grow, the
longer they survive, and the better they
connect with other nerve cells. Exercise, such as brisk walking for 40 minutes four times a week, increases blood
flow to the regions of the brain shown
able to grow new cells. “In our lab,
when we discovered this, people started
taking walks during their lunch hour,”
says Gage. Movement is so crucial to
brain health that some of the cognitive
changes blamed on aging may in fact be
the result of inactivity, he adds.
Another simple, brainpower-boosting
habit: pay attention to what you’re
doing. As we age, we become more
prone to distraction, thanks to some
of the same brain changes that can
hamper our thinking speed. But even a
split-second loss of focus can prevent
a memory from being properly stored.
So when you put down your glasses,
focus on where you put them; they
may be a whole lot easier to find.