Brain at Work
Advanced Technology Lets Scientists Watch

By Ned Potter

A L B U Q U E R Q U E, N.M., Jan. 14

‹ The machine looks like a giant hair dryer, or perhaps something the Bride
of Frankenstein might wear. It is one of the most powerful brain-imaging
devices in the world.


Scientists call it M.E.G. ‹ short for Magnetoencephalography ‹ a scanner
capable, unlike any before it, of showing activity in the brain as it
happens.

"If the brain is trying to do something with information from the outside
world, and all the different parts are working a little bit out of
synchronization, then the whole picture won't emerge in a coherent kind of
way," said Claudia Tesche, a psychologist who helped design the scanner. "We
need to know how the brain is processing information on a moment-to-moment
basis."

"We can look at changes in brain activity on a millisecond level," said
Cheryl Aine of the University of New Mexico, one of the leading researchers
in the field.

Electrochemical Signals

The M.E.G. scanner makes that possible because the brain actually runs on
tiny pulses of electricity. Every thought, every reaction you have to
something, becomes a series of minute electrochemical signals among the
cells in your brain.

Weak as those signals are, they can be measured by the 122 sensors in the
M.E.G. scanner that surround one's head. The scanner is extremely sensitive,
and must be shielded so that it is not overloaded by all the other
electromagnetic noise around us. Its ability to detect brain signals amid
everything else, says one researcher, is comparable to "being able to hear
an insect's footsteps ‹ at a rock concert."

"We can get a picture ‹ a very clear picture ‹ of what's going on inside
someone's head without touching them at all," said Michael Weisend, a
researcher who has worked extensively with M.E.G. "You just get to sit down
and look at the operation of the living brain."

In the imaging center at the New Mexico Federal Medical Center in
Albuquerque, we were introduced to a woman named Annie. Three years ago, she
began to show symptoms of schizophrenia ‹ unable to distinguish reality from
illusion.

"I started getting paranoid that they were going to come and kill me while I
was sleeping, and so I started sleeping in my car," she said.

With medication, she's now much better, but doctors would like to know what
goes on inside her head. So Aine ran her through a test of cognitive
abilities, while she sat with her head in the scanner.

Order and Chaos

When the results are processed by computer, they generally show the workings
of the human brain to be remarkably orderly. If an image is flashed on a
screen in front of a healthy person, for example, the scanner shows a
response in a region in the back of the brain that processes vision.

If the image happens to be of a word, the activity will transfer to the
frontal lobe, which handles higher logic and language. The M.E.G. scan shows
that all this happens in about half a second.

"The schizophrenic doesn't do that," said Tesche. "The activity keeps
fluttering around from one brain area to another."

The result is chaos ‹ a harmless picture may inadvertently be processed by
parts of the brain that usually process touch, or taste, or even fear. It
may, scientists surmise, explain why people with schizophrenia sometimes
hallucinate.

But researchers now have unprecedented ability to see what is going wrong in
the brain ‹ in schizophrenia, epilepsy, and many other disorders ‹ and,
perhaps, armed with the new information, find cures.  

http://abcnews.go.com/sections/wnt/DailyNews/brain_imaging030114.html