NEW ORLEANS — In pursuit of happiness, fear and the other feelings played on the mood organ of the mind, scientists for the first time are systematically exploring the anatomy of emotion.
Mapping the brain's emotional landscape, researchers are learning how love alters the brain's neural activity. They have detected the inner turmoil that strong words can stir.
They can see how the biochemistry of feelings clouds the brain's ability to think clearly or create accurate memories. They are discovering how the brain must change its emotional ways to master the dark disturbances of depression.
By examining the complex neural circuits that underpin emotional states, researchers are tackling a subject long considered too subjective and ill-defined for fundamental scientific study.
Once relegated to the fringe, the study of emotion in recent years has taken on new respectability with technical advances that make it possible to reliably monitor such subtle mental states. Positron emission tomography (PET) and functional magnetic resonance imaging have become tools of choice for the painless dissection of human emotion.
"Emotion research has been a stepchild," said Steven Hyman, director of the National Institute of Mental Health. "Until recently, the study of emotion was seen as suspect compared to the study of cognition.
"Now we are seeing that, like thinking, emotions rely on specific neural circuits," Hyman said. "We are just at the beginnings of understanding how these circuits interact, of understanding how thinking and emotions interact."
Researchers are learning in detail how the brain treats human emotion as a type of information. This information is processed through neural circuits shaped by evolution to bolster individual survival or to regulate the body's biochemical well-being.
Emotion, scientists are discovering, is not centered in any one part of the brain, but reaches into almost every furrow of the dynamic and fickle organ of thought.
"Emotion is not regulated in one place; it is a network of areas," said neuropsychiatrist Dr. Helen Mayberg at the University of Toronto, who uses a variety of imaging techniques to study the neurobiology of depression and other mood disorders. Emotion is the body's way of tying together a range of physical, mental and biochemical responses, she said.
"You need to have a system that will link up your thinking, feeling, your gut reaction, your subconscious reactions, to coordinate your thinking with the automatic parts of your brain."
