While the folks at the Human Genome Project steal the science headlines, UCLA’s Dr. John Mazziotta and a world-wide team of brain researchers go quietly about the business of creating a comprehensive map of the adult human brain. This group, the International Consortium for Brain Mapping, ICBM, believes the human brain map will reveal a spectacular amount of information on the brain, information that will help identify and treat brain disorders, reveal more precisely brain mechanisms involved in memory and learning, and perhaps even give us insight into the more powerful workings of the mind.
What sets the brain map apart from other tools for studying the brain is its mere expansiveness. Just like no two people or no two human bodies are exactly alike, neither are any two brains. In fact, there is a wide variability among human brains. Existing tools for studying the human brain, however, are based on only one or a few brains. The brain map will change that.
"Unlike the earth, where there’s one unique physical representation for a given place which doesn’t change too much, the variance among individuals for brain anatomy is high—and we don’t know how high," says Mazziotta, vice chair of neurology at UCLA.
“Our goals are to develop a system so that we can provide the community with the architecture of the human brain, and a way to navigate through it.”
The brain mapping project is building what it calls a "probabilistic reference system for the human brain." This means that, when finished, the brain map will include information about as many probabilities in the healthy adult human brain as possible. (Research will commence soon to study brain disorders, such as Alzheimer’s disease and schizophrenia, using similar approaches.)
"Our goals," Mazziotta says, "are to develop a system so that we can provide the community with the architecture of the human brain, and a way to navigate through it. Atlases in the past have taken one brain or one part of a brain and tried to stretch or compress other brains to match it, without any information about the variability. Our system captures all that variability and gives you a probability of where you are—because the sample is big enough to do that."
The project to map the human brain, says Mazziotta, was born out of his own frustration. "You can hardly pick up a newspaper without reading about some functional imaging study," he says, "and yet, we don’t have a good way to exchange and compare results, because everybody’s anatomy is different. So we needed a system where you could put data in, retrieve it, and be clear about how accurate that would be."
“When you have this kind of knowledge about how wide the range of normality is, the sensitivity to detect disorders is very high.”
To create the comprehensive brain map, researchers around the world are using magnetic resonance imaging machines, fMRI and PET technologies to scan the brains of 7,000 healthy study volunteers between the ages of 18 and 90. In addition, a DNA sample is recorded for each volunteer and a detailed history is compiled that includes information about educational background, ethnicity, family history, and medical history. Volunteers undergo neurological, psychological and neuropsychiatric exams, as well as handedness testing. So far, 5,300 volunteers have gone through this testing stage of the project.
Research on the project is divided into four main areas: data acquisition, function, anatomy, and analysis.
The brain map will be used perhaps first and most widely where the need is greatest: diagnosing and treating neurological disorders with a precision currently not always available. Because the completed brain atlas will contain information from thousands of healthy adult brains, the degree of what constitutes "normal" will be much more clearly understood. Therefore, even the slightest departure from that baseline will be more easily recognized. Mazziotta explains a possible scenario of how this might work in a hospital setting:
"Say a patient comes to the emergency room. She’s had a seizure. Based on the patient’s symptoms, you think well, it might come from the right frontal lobe. So the person has an MRI scan and it’s normal. A radiologist looks at it, qualitatively: it looks normal. A 3-D reconstructed is done and it still looks normal. Compare it to the 20 or so normals that hospital might have available: it still looks normal."
"Then, warp that it into this database and compare it to 7,000 people, and it’ll say, well, this fold is in slightly the wrong place. You could say, I want to compare this to the best match you have: I only want 23 year-old, left-handed, Asian women who’ve had two years of college, smoke cigarettes, and have read Gone with the Wind. The database could come back and say, well, we have 18 of those. And that part of the cortex is a half a millimeter too thick, this fold is rotated, and that’s the area of the brain that’s abnormal; everything else seems fine."
"When you have this kind of knowledge about how wide the range of normality is," says Mazziotta "the sensitivity to detect disorders is very high."
The brain mapping project also holds promise for increasing our understanding of human learning, which could have a big impact on education. Mazziotta believes that brain mapping tools could clarify not only the brain mechanisms that underlie learning, but help define strategies for better learning. Given this information, he says, curriculum could be designed based on what the brain is wanting to do rather than what the educational system has developed.
To wit, says Mazziotta, we might someday even use brain mapping to get to the bottom of the phonics v. whole language debate.
"Why not scan children who are just about to learn to read?" he asks. "Then have a battery of tasks that may help to elucidate the strategy that each individual is using."