The Johns Hopkins Gazette: February 1, 1999
Feb. 1, 1999
VOL. 28, NO. 20


New Center For Brain Imaging

By Gary Dorsey
Johns Hopkins Gazette Online Edition

Scientists from the university and the Kennedy Krieger Institute have collaborated to create a state-of-the-art center for brain imaging that has aroused a horde of ideas across the state of Maryland for mapping the human mind.

On Jan. 11, just days before the new imaging technology arrived for installation, a crowd of physicists, radiologists, psychiatrists and neuroscientists stood elbow-to-elbow to share their hopes and applaud projects that should expand the frontiers of their disciplines.

The gathering created a festive air in an auditorium of the Houck Building at the School of Medicine. As the room filled with researchers from the University of Maryland, Kennedy Krieger and Hopkins departments of Psychology, Radiology, Neuroscience, Psychiatry, Biomedical Engineering and Mathematical Sciences, it was apparent that the level of anticipation was high.

Billed as a symposium on brain research, the event was scheduled to introduce a very serious, very eclectic group of scientists to the kinds of projects that could occur inside the new facility--everything from studying the effects of alcohol on driving skills to mapping the pathways of human memory (see accompanying story below).

But in their standing-room-only crowd, the scientists seemed more in the mood to celebrate.

"I always thought this would happen some day," observed Mike Kraut, an assistant professor in the Department of Radiology, as he began his presentation on functional imaging of vision and language. "But I thought I'd be in a nursing home when it did."

The idea for building a functional imaging center was born at the start of this decade when a handful of people at Hopkins and Kennedy Krieger recognized that a new technology called fMRI, or functional magnetic resonance imaging, would soon revolutionize the field of neuroscience. Unlike already existing equipment for mind/brain research, fMRI can create images of brain processes in near real-time, pinpoint neuronal activity with accuracy and be used repeatedly over time without threatening human health.

Gary Goldstein, president of Kennedy Krieger, and Guy McKhann, who directs the Mind/Brain Institute at Hopkins, envisioned a place where fMRI could be used for basic research that would not only benefit children with developmental disabilities but also galvanize talented scientists across the state. McKhann unified the support of the Hopkins community, and Goldstein raised the funds and sacrificed the library at Kennedy Krieger to house a state-of-the-art center.

"The most important day, however, came in December 1997," recalled Peter Van Zijl, a professor of radiology. "That was when the F.M. Kirby Foundation agreed to fund the center." Today, Van Zijl serves as director of what will be called the F.M. Kirby Research Center for Functional Brain Imaging.

A few other functional imaging centers exist in the United States, but the Kirby center will be unique because it is the only one specifically designed to be "child-friendly" and strictly dedicated to research rather than clinical purposes. Another characteristic that makes the center distinctive, Goldstein said, is that one of the major goals is to stimulate collaborations among scientists from diverse disciplines and "encourage an interactive group."

The potential for interaction has already spread beyond the confines of the Hopkins campus, where faculty from eight different departments are lining up potential projects to implement at the center. Scientists from the University of Maryland at College Park and at Baltimore County also have been drawn into the group with projects related to hypertension, tone recognition and human memory.

More than two dozen scientists presented inspiring synopses of their research goals over a period of three and a half hours that day. With such keen interest, it seems sure that the new center will see a lot of use once it opens formally in May.

Even for those who have never relied on the technology, the excitement is infectious.

"I haven't done any functional imaging yet," said Howard Egeth, chairman of the Hopkins Psychology Department, as he stood before his new colleagues. "So I will tell you what I'm interested in. And if you have any ideas of how I might use functional MRI, catch me over the coffee break."

From the Mind of Monkeys:
New Clues to Evolution of Human Brain

In her quest to examine the contents of consciousness, Susan Courtney, a professor of psychology, has produced new evidence of the evolutionary path from the monkey brain to the human.

Courtney recently reported that she had pinpointed the place where the human brain stockpiles information about spatial relationships for short-term use.

It was not where anyone expected.

Until recently, many scientists argued that storage depots for short-term memory (called "working memory") in humans were probably located in the same place as in monkeys; memory of spatial relationships was thought to be stored in the top half of the frontal cortex and memory of objects was stored in the bottom half.

But using a relatively new brain-mapping technology called functional magnetic resonance imaging, or fMRI, Courtney discovered that the human brain has a dedicated place for spatial working memory located farther back in the brain anatomy.

"Until now, it's been rather controversial," Courtney said, "because people have based their theories about human brain physiology on what they have seen in non-human primates. And yet when scientists went looking for a particular place for spatial working memory in humans, they couldn't find it. But now, with the help of new technologies such as fMRI, we can see where the human brain handles some of its short-term storage."

The difference has interesting implications for human brain evolution, Courtney said.

"The comparison indicates that there has been a great expansion of the frontal cortex in the evolution from monkeys to humans, pushing this older area, reserved for spatial memory, out of the way," she said. "Of course, one of the big questions is what replaced it. From the imaging work and from studies of people with damage to that part of the brain, it looks as if these 'new' areas are involved in functions that are, if not uniquely human, then greatly more developed in humans--for example, abstract reasoning, planning for the future and manipulation of information."

In the past, researchers who wanted detailed studies of human brain activity struggled because they lacked effective investigative tools. In experiments with people, two of the best technologies brought only limited success in mapping the processes of consciousness. An electroencephalogram, for example, could not pinpoint where brain signals were coming from, and positron emission tomography required radioactive tracers, which limited the exposure times of subjects; PET was also restricted because it could only provide an image of brain activity integrated over a minute or two.

Consequently, researchers have relied on monkeys that have undergone invasive surgery and the implantation of electrodes into the brain for monitoring biological activity. For that reason, the primate brain has served as the model for understanding some of the finer aspects of human brain performance.

Functional MRI, however, can be used repeatedly on human subjects without causing harm or relying on invasive procedures. Plus, the resolution is so good that scientists like Courtney can observe changes in the brain every few seconds, allowing them to chart neural activity nearly in real time.

For Courtney, who is discretely examining what she calls "the contents of consciousness," functional imaging has advanced her work considerably. Besides revealing clues about human brain evolution, her latest work with functional imaging also revealed that the process of retrieving short-term memories of faces shares the same physical mechanism in the brain as that for retrieving long-term memories of faces --forcing yet another wedge into the mysteries of consciousness.

"It's great uncharted territory," she said. "But we're beginning to make a lot of progress."

Her work was funded by the National Institute of Mental Health and reported in the Philosophical Transactions of the Royal Society of London.
--Gary Dorsey