Fighting Fear: Researchers Seek Targets for Treatment
April 4, 2001 (Washington) -- Fear can be a powerful influence on behavior, even when we don't think about it. For example, it does not take a genius to figure out that coming face to face with a tiger would not be a good thing. But did you ever wonder why a caged tiger does not trigger the same response?
Thanks to new brain imaging techniques, mechanisms for tracing pathways of nerves in the brain, and instruments to measure the brain's electrical activity, scientists finally are beginning to answer this and other questions regarding human phobias and fears.
Many of the developments have been made in the last decade. Recent advances range from the development of the electroencephalograph, an instrument used to measure the electrical activity of the brain, to computer-assisted imaging techniques that can be used to visualize the structure of a living brain.
Anyone can experience fear. But when fears become persistent and are associated with anxious anticipation or avoidance of triggers that spark the fear -- enough to interfere with your life and disrupt your ability to function -- then it's not just a fear; it's a phobia, and phobias generally require treatment.
By developing a virtual map of the brain's activity when confronted with danger, researchers now hope to someday develop treatments to aid everyone from those who are afraid to leave the house to those who suffer from everyday phobias, such as the fear of heights or even spiders.
"The clinical implications are very simple. If you know the basic circuitry, you know where to look," explains Michael Davis, PhD, a professor of psychiatry and behavioral sciences at Emory University School of Medicine in Atlanta.
One target of the present research is a small part of the brain, located behind the temple, called the amygdala. Since 1939, scientists have suspected that the amygdala may play a large role in how people respond to fear and phobias.
In animals, it has been demonstrated that the amygdala acts much like a "smart" alarm, evaluating the surrounding environment for danger signals and inhibiting or facilitating a fear-related response as warranted. For instance, it has been shown that while the amygdala might trigger a rabbit's heart to beat faster when a predator is at hand, to enable him to run away -- it also could inhibit this natural reaction if the rabbit is caught and needs to play dead.
The new technology is now helping researchers confirm those suspicions and apply animal research findings to the human brain.
At a major conference sponsored by the National Institutes of Health, Davis and other pioneers in the field recently gathered to share their insights.
Significant progress has been made due to human participation, according to the researchers, because unlike animals, humans can describe their emotions, explains Richard Davidson, PhD, a professor of psychology and psychiatry at the University of Wisconsin in Madison.