Pioneers of Promise
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Where Mind Meets Brain
By Dale Keiger
What goes on in our heads is fundamentally interdisciplinary. You have the brain: neurons, synapses, electrical activity, chemical reactions, all those lobes and ganglia and folds of gray matter. And you have the mind, the higher functions of perception, consciousness, memory, creativity, and intellection. Anatomy meets cognition meets psychology, in a continuous cranial seminar.
In the mid-1980s, a group of men at Hopkins led by Steven Muller, then president, and Vernon Mountcastle, now professor emeritus of neuroscience, met to discuss the accelerating breakthroughs in the study of the brain. Recalls Mountcastle, who has done seminal research on higher-function neurons and the modular grouping of brain cells, "It started on a day when Steve Muller had one of his get-togethers out at the Evergreen House. What to do about brain sciences? Many suggestions were made by people, largely pertaining to increasing the size and efficiency of their separate enterprises. I made the statement that this wasn't the way to go, that there's a new wave in brain science. I described what I thought would be an ideal solution." Mountcastle's ideal solution was a new interdisciplinary research center: the Mind/Brain Institute.
Muller concurred. He says now, "It would be nice if I could say that there was some great flash of genius, but it was a sort of simple-minded thing. It turns out that we are living in a time when we are learning a tremendous amount about the brain, and we are in the position to also learn more about how the mind works. The problem is the people who know about the brain tend to be in the School of Medicine, many of them clinicians, and the mind people are in Arts & Sciences, basically. So it seemed like an interesting idea to see whether some kind of synergy could be established in a new institute that focused on the interaction between mind and brain." And, according to the formal proposal for the institute, written in 1987, on the interaction among scholars and researchers from molecular and cell biology, biochemistry, pharmacology, systems neurophysiology, neuroanatomy, cognitive and experimental psychology, clinical neuroscience, psychiatry, computer science, engineering, and philosophy.
The path from concept to execution was not smooth. Assembling people, resources, and facilities was a major undertaking, and in the late 1980s, just as the institute was trying to find its legs, the university entered a period of fiscal crisis. But a $7.5 million grant from the Zanvyl and Isabelle Krieger Fund in 1990 (as well as significant contributions from other sources, including more than $1 million from the L. K. Whittier Foundation) enabled the institute to create its own facilities on the Homewood campus and initiate research. Then the Bard Laboratories, already highly regarded (and well funded) for its neuroscience research, moved from the School of Medicine to Homewood and became part of the new institute. Says Mountcastle, "Within six months of that, Mind/Brain was up and running with activities going on in every laboratory. Suddenly, here was Bard, a world-class outfit--bang!--right into the institute. It made it a going concern from Day One."
Guy McKhann, Hopkins chief of Neurology, was appointed Mind/Brain's first director. He and his colleagues decided to focus not on what happens in the brain at the cellular level but at the systems level. The institute now has 10 researchers; seven concentrate on the neural mechanisms of perception, and three on the plasticity, or adaptability, of the brain, especially after injury or insult to the nervous system such as the amputation of a limb or a hemispherectomy. Mind/Brain is capitalizing on dramatic improvements in non-invasive imaging of neural processes, such as PET scans and significantly enhanced MRI technology (known as functional MRI, or fMRI), to study human neural processes. McKhann projects a doubling of the research staff to 20 within the next five years.
Among the institute's current projects:
Ken Johnson, the incoming Mind/Brain director (McKhann planned to retire from the directorship just as Hopkins Magazine was going to press), has been doing pathbreaking work on the neural basis of somatosensory perception, what non-neuroscientists call touch. How do blind people read Braille? How is information about form and texture represented and interpreted within the brain?
Rudiger von der Heydt studies the neural processes underlying visual perception. How is it that we see the world three-dimensionally even though vision is based on two-dimensional images projected on the retinas? How is color computed in the brain? In a scene of many objects, how do we know which color goes with which object?
Michael Steinmetz is looking at selective attention. The brain receives far more information than it can process. What are the neural structures and physiological mechanisms by which the brain sorts out what to attend to and what to ignore?
The Krieger Institute hardly has a monopoly on brain science at Hopkins. Michela Gallagher of the Psychology Department has helped discount the prevalent theory that people encounter memory problems as they age because brain cells die off. Her research has found no connection between normal aging and neuron loss. The Hopkins Department of Cognitive Science works in a field so new that 10 years ago at its founding, it had but one counterpart in the country. Professor Paul Smolensky and his colleagues specialize in formal, computational theories for understanding how the brain functions, especially in regard to language.
Not that long ago, Smolensky notes, linguists studied how language works, and brain researchers could identify where in the brain language was centered, but the two disciplines didn't meet. Smolensky says, "In the old days, a linguist would say to a brain scientist, 'Okay, you tell me that when I speak English, something happens here instead of here.'" He taps his temple in two places. "And the linguist would then say, 'That's interesting, but that tells me nothing about linguistics.'" Cognitive science, he says, is bringing the two together as a field of study, integrating those and other disciplines.
Along with Alan Prince of Rutgers University, Smolensky has developed Optimality Theory, which links how grammar works with the processing of the brain. For quite some time linguists have posited that a "universal grammar" underlies all languages. How then to explain the extraordinary variations in human tongues, from Urdu to English to Swahili to Finnish to Tagalog? Prince and Smolensky believe that a myriad of grammatical rules, or "constraints," underly languages, but often conflict. (One example of a constraint: sentences need subjects.) Languages vary because each sorts these conflicts into its own hierarchy of priorities. The result is German, or Russian, or Japanese, all of which work equally well as languages, but are significantly dissimilar.
That much is pure linguistics. Can it be linked to cognitive functioning in the brain? Smolensky believes it can. He and Prince note that when the brain deals with language, a shifting pattern of activity moves about the neural network until the brain finds an optimal pattern. The process by which the brain sorts out these networks strongly resembles the process of grammar posited by Optimality Theory. Smolensky thinks that grammar may be realized in a neural network that follows rules of optimization.
McKhann and colleagues believe that Hopkins is uniquely situated with the resources to create a pathbreaking research and educational program in mind/brain science. They're developing an undergraduate neuroscience major that has proven to be extraordinarily popular, with more than 100 students enrolled. They continue to look for ways to achieve further integration of the many disciplines now studying all aspects of the brain and its higher functions. Says Mountcastle, "Discoveries are always made by one or two people. Groups of 10 or 12 people can't sit around a table and discover anything. But they can exchange ideas and stimulate each other in very profitable ways."
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