Imagine you have a
you're too fried to face a busy
workload. Rather than taking
aspirin or coffee, you put a small
device the size of an iPod to the back of
your head and push a button to revitalize
your brain. Sound futuristic? It may
not be many years away.
Scientists have scrutinized the
human brain for thousands of years,
but with the use of electricity and magnets,
medical researchers are getting
closer to identifying the areas -- and
creating the tools -- that stimulate and
repair the mysterious organ.
Eric Wassermann, a neurologist
and chief of the Brain Stimulation
Unit at the National Institute of
Neurological Disorders and Stroke (NINDS), has come
closest to creating an inexpensive,
painless "thinking cap." The device
runs on electrical currents, known as
transcranial direct current stimulation.
His studies have shown that tDCS can
boost verbal skills in healthy people
by as much as 20 percent.
In one study, volunteers were asked
to recall and say as many words that
begin with a particular letter as possible,
then passed a tiny (2-milliamp) current through electrodes
attached to their foreheads. The volunteers were quizzed again using a
different letter with the current on and were able to come up with
20 percent more words. The only side effect so far has been itching or
tingling on the scalp.
Wassermann can't pinpoint exactly what is happening, but he
thinks tDCS lets the prefrontal cortex, the brain part associated with
verbal memory, transmit signals more easily. Any function associated
with a specific region
of the cerebral cortex
(the outer edges of the
brain) is potentially
within tDCS's reach. The goal is to make the targeted area work more
effectively, like giving it a small cup of coffee.
"It doesn't cause neurons to fire on their own -- it needs to have some
drive on them to do so," says Wassermann. "It's a little like treating
specific nerve cells locally with a drug, so it could be a very helpful way
of boosting brain function in people with brain disorders and injuries."
Even though he is focusing on tDCS for more heavy-duty problems
like head injuries and dementia, Wassermann does not rule out a thinking
cap that any healthy person could use to boost brainpower with the
flick of a switch. The device is already
simple and easy to make, he says.
"Anyone with the know-how could go
to an electronics store, buy the components,
and build one. It's simply a 9-volt
battery, a couple of wires, and some
pieces of wet sponge. The question now
is, what part of the brain do you stimulate,
and how can it actually help you?
That's what we're still trying to learn."
Neurologists are also using electricity
to try to treat various brain disorders,
from Parkinson's disease to headaches.
As early as 45 BC, a Roman court physician
named Scribonius Largus noted
that the application of live torpedo fish,
a type of electric ray, to patients' foreheads
cured headaches. Greek physician
and philosopher Galen noted the same
findings a century later.
version of Largus's and Galen's fish
involves magnetic pulses in an up-and-coming
treatment known as transcranial
magnetic stimulation. Techniques
are still being refined, but researchers
know that by placing a TMS device on
different areas of the head, they can
make fingers twitch or freeze speech in
mid-sentence. Doctors treating depression
aim the magnets at the prefrontal cortex, while those treating
migraine headaches go toward the nerve centers in the back of the head.
"There's evidence that migraines start with electrical hyperexcitability
in the brain's cortex," says Yousef Mohammad, a neurologist
at the Ohio State University Medical Center, who has found evidence
that a TMS device placed against the back of the head can prevent
migraine pain. "Our theory is that if we can break that with two pulses
of an electromagnetic field, we can abort a headache before it starts."
Mohammad is working
with a medical company
to research a portable
TMS device the size of a
hair dryer, and recently launched a bigger study nationwide.
Wassermann has also tested TMS by using himself as a guinea pig.
He had a fellow researcher target his brain's speech centers by zapping
him while speaking, which stopped him in mid-sentence -- a feeling
he calls "indescribable."
So next time you feel frazzled or foggy, think of strapping on a
catchy-looking gadget and gently jolting your way to rejuvenation.
Now, that's an electrifying thought.
Vanessa Richardson is a freelance writer in San Francisco.