WIRED
Understanding gray matter has long been a gray area for researchers but now they are using new, high-tech brain-mapping equipment.
Written by Julie Toland
Gray matter has long been a gray area for researchers.
But new, high-tech brain-mapping equipment at Texas Tech University Health Sciences Center is helping School of Allied Health researchers unravel some of the mysteries about how the brain works.
The school’s Center for Functional Brain Mapping and Cortical Studies in the Department of Communication Disorders recently began using electronic brain mapping equipment, which offers a look at the responses of the brain stem to different sounds.
"Basically, what we’re doing is watching the brain think," said Dwayne Paschall, Ph.D., assistant professor in the Department of Communication Disorders. "The way that the brain works is to send small electrical signals from one location to the next. And by putting electrodes on the outside of the head, we can watch it send that electrical signal from location to location. Then we can draw this information onto a visual image of the patient’s brain and see which parts are working.
"This allows us to create a map to watch how the brain is sending signals all over the head," he said.
Paschall said brain mapping is useful in a variety of situations Ð hearing loss, brain damage and any kind of speech problem. It is especially effective in assessing those who have difficulty communicating verbally. For example, a young child who has difficulty hearing can be tested while asleep. "We can give them different sounds to listen to and see how the brain is functioning to process those sounds," he said.
"In an older patient who may have had an accident or a stroke, we can measure how the brain is recovering after that particular incident, and monitor the change in language. And sometimes in coma patients, we can measure brain changes and determine with some success when that patient is likely to recover."
The brain-mapping unit also can be used in the operating room to monitor the patient’s nerves or neural function during surgery. "We monitor several different modalities during an operating room session," Paschall said. "We have electrodes in different parts of the body, which is especially useful if the surgeon is working around nerves."
A number of different brain-mapping techniques are currently being used, Paschall said. Functional MRI (WHAT DOES THIS STAND FOR?), which is more commonly known, monitors changes in the brain that happen over a second or two. And Positron Emission Topography (PET) measures changes in certain electro-chemical properties of the brain.
"What we’re measuring with our brain mapping equipment is actual electrical signals in the brain," Paschall said. "We can take them and superimpose or lay them on top of an MRI picture of the brain. This way we can see exactly which bumps and ripples in the brain are producing the activity, which parts are actually working. And we can measure that as it changes very quickly over time." Paschall said a difference between this technique and MRI or PET methods is it allows measurement of activity over the entire surface of the brain, rather than just one nerve or one neuron, and on a very fast time scale.
"We know that the brain has a lot of different parts, and we know different parts are involved with doing a single activity," Paschall said. "So something as simple as writing or listening in a noisy environment involves multiple areas of the brain, and if we’re just looking at one part, we’re missing how the brain functions as a whole.
"This equipment is what allows us to do that, to look at the whole brain and see how all the different parts come together to solve one particular problem."
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