Getting Emotional

By Dian Land

Despite the doubts of others, Kalin and Davidson stuck to their agenda. More than a decade ago, each began producing research findings that captured attention.

Kalin learned, for instance, that in monkeys - and by close association, very likely humans - some chemical circuits in the brain control reactions to fear, while others control responses associated with affection and affiliation. Davidson discovered that different sides of the same brain structure control different emotions, and that people with elevated activity in one side are generally more cheerful and engaged in life, while people with greater activity in the other are often more pessimistic and withdrawn. The scope of UW investigations has since expanded to topics that examine emotions from all angles.

During the past three years, Kalin has noticed a complete about-face in attitudes of the naysayers, with decision-makers at the National Institutes of Health and other scientific peers now accepting the viability of research into emotions. The symposium that Davidson first organized seven years ago, which has been sponsored by HealthEmotions since 1998, has blossomed into the premier meeting in the field.

"This new interest is very probably an outgrowth of the work we and others have done, bringing the subject to the forefront and backing it up with solid data and good science," says Kalin. "Affective neuroscience has finally become established as a respectable science."

The university, the Medical School, and the Graduate School have been "incredibly supportive all along," says Kalin. UW administrators intensified their support recently by allocating two "cluster hires" - interdisciplinary teams of faculty that work in emerging research areas - to brain imaging research.

Both Kalin and Davidson emphasize that a key factor in their success has been UW-Madison's tradition of fostering fruitful cross-fertilizations among departments and research units. This unique atmosphere has helped fuel their friendship, which began with a shared passion for the science. The connection between the two men clearly affects how their respective academic departments interact - the very collegial psychology-psychiatry relationship they have is rare.

"It is the chemistry among us all - our ability to work together as a group and be scientifically creative and take risks - that makes us so special and leads to significant advances," says Kalin of the approximately two dozen UW researchers who have been drawn together by similar questions.

The answers to those questions in all likelihood lie within the structures of the brain, whose complexity has long fascinated scientists, but whose inner workings are only beginning to be understood. With the help of exciting new imaging technology, particularly functional magnetic resonance imaging (fMRI), for the first time scientists are able to visualize the brain while it's working and see areas that are most active during certain kinds of stimulation. In one study, for example, a subject lies in the scanner and looks at pictures - from adorable toddlers to grisly accident scenes - that elicit a range of emotional responses. An fMRI scan shows specific brain structures in action by detecting increases in oxygen resulting from surges in blood flow. Positron emission tomography (PET) technology, which tracks biochemical processes in the brain, is also highly illuminating to scientists.

"The imaging technology has been an amazing advance over the last decade," notes Kalin. Without the sophisticated equipment, researchers must rely solely on traditional behavioral studies to glean understanding of emotions. While such studies have provided - and will continue to provide - many valuable lessons, the ability to peer noninvasively into the live brain is revealing on an entirely new level.

The Keck Laboratory is the nerve center of emotions research at UW-Madison. The $10 million lab houses the latest model fMRI machine, driven by a sixteen-ton magnet that is so strong it can pull a hammer out of a worker's hand. An on-site tandem accelerator produces radioactive tracers for use with the PET scanner. Research subjects can also be fitted with a cap that contains 256 ultra-sensitive sensors that pick up electrical signals, a combination that provides one of the most comprehensive looks inside the working brain obtainable today.

With each imaging experiment, scientists at Wisconsin and elsewhere are learning more about critical emotion-linked brain structures. They are finding, for example, that the almond-shaped amygdala deep in the brain generates many different kinds of fear. Complementing their studies in humans, Kalin and his colleagues will soon be doing PET studies of monkey brains to confirm their laboratory finding that, contrary to expectations, the amygdala does not process all kinds of fear.

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