“Egyptian physicians believed the heart was the site of consciousness,” he said. “They had no concept that the brain was associated with feeling, thinking or other functions. For them, brains were for eating. It wasn’t until the Greco-Roman period that the notion of the brain’s connection with thought and feeling was introduced, but even then, the idea that the heart was the seat of passionate emotions persisted.”
The Egyptian view might seem primitive in light of today’s storehouse of information about mental functioning, but remnants of the old thinking hang on in the idioms, metaphors, songs and celebrations of our own time that link the heart with a host of complex human emotions, especially love.
“The neurobiology of love has been a difficult topic to approach,” Thompson conceded. “No one has yet been able to tackle and fully explain it.”
Promising Research Emerging
Kalin and his staff at the HealthEmotions Research Institute have chosen to forgo the typical focus on negative emotions such as depression and emphasize the no-less-interesting or important positive emotions. This has led them to pursue a host of questions seldom unexamined by medical science. For example:
What exactly is happening in the brain to make activities we enjoy produce the warm glow of contentment? What makes some people more upbeat than others? What areas of the brain are important in controlling our desires to connect with one another?
“We are just beginning to discern what parts of the brain are responsible for certain positive emotions,” Kalin explained. “For example, we are finding that some of the newer, more recently evolved neural structures, such as the limbic system, play vital roles in emotional expression. At the same time, we’ve found that these limbic structures are controlled or modulated by other areas of the brain, such as the prefrontal cortex. Our work for the near future is to determine how these and other areas of the brain actually function in human emotional response.”
Kalin’s colleague at the Institute, Richard Davidson, M.D., the William James and Vilas Research professor of psychology and psychiatry at the University of Wisconsin-Madison, is at the forefront of the effort to better understand how the brain processes and expresses emotions.
Davidson, who heads up the Keck Laboratory for Functional Brain Research at the Institute, has been studying how differences in the structure of the brain are related to the diverse ways individuals express positive emotional states. Much of his research utilizes modern imaging methods such as positron emission tomography (PET) and functional magnetic resonance imaging (MRI) in the quest for better understanding of the relationship between the brain and emotions.
These imaging technologies allow researchers to search for patterns of common brain activity in individuals with similar emotional orientations. In particular, he and his team have been examining the brain function in people whom they characterize as having “approach-related positive emotion.”
Davidson says such individuals are characterized by enthusiasm, alertness, energy, persistence in goal orientation and other positive behavioral characteristics. The research so far has shown that the brains of such individuals are also distinctive: They show what Davidson’s research describes as “a pattern of left prefrontal activation.”
“This pattern is precisely the opposite pattern of the prefrontal activity that occurs in depressed individuals, which is a pattern of right prefrontal activation,” Davidson noted. “In infancy and early childhood, individuals with the pattern of left prefrontal activity show signs of exuberance and are highly social.”
His effort has also determined a possible link between the functioning of another region of the brain called the amygdala and negative emotions and stress.
“We’ve already discovered that there are differences in the amygdalas of people who appear to be these happy, positive individuals compared with those of individuals who show more vulnerability and more depressive emotion in response to the emotional events in life,” he said.
Shift Toward Health and Resilience
Kalin believes that research of this type signals a new era of scientific inquiry. “Scientists have begun to redirect their attention from problems that produce disease to brain systems that regulate positive emotions and their relationship to key physiological systems affecting health,” he said. “This approach can help us develop new strategies to promote health by decreasing susceptibility and increasing resilience to disease.”