NEW YORK, Jun 17 (Reuters Health) -- "The only thing we have to fear is fear itself," said Franklin Roosevelt.

What Roosevelt did not know is that the brain has areas wired to deal with the expectation of pain. A report on these findings is published in the June 18th issue of the journal Science.

The findings may explain why thinking about a trip to the dentist can make people shake well before they even hear the sound of the drill.

"In people with chronic pain, such as those with back pain or arthritis, their experience can be exacerbated by anticipation and expectation of pain," researcher Dr. Irene Tracey of the University of Oxford in England told Reuters Health. "Now we can begin to see if anti-anxiety drugs and/or various behavioral therapies can help them learn to better cope with the expectation of pain."

Using a brain-mapping technique called functional magnetic resonance imaging (MRI), researchers were able to identify the areas where the brain processes anticipation of pain and actual pain. Anticipation of pain is processed in the frontal region of the brain, the cerebellum (located at the back of the brain), and another area of the brain called the insular cortex. These areas are found close to the brain regions that respond to an actual painful event such as a root canal or the joint pain and stiffness of arthritis.

In a series of experiments conducted on 12 healthy volunteers, researchers measured brain activity of participants as they felt warm sensations and painfully hot sensations. Each sensation was preceded by a colored light.

Eventually, participants learned to associate certain colored lights with impending pain.

Using the functional MRI, the researchers were able to locate the areas of the brain that process the expectation of pain.

The investigators conclude that their findings may help to develop "therapeutic possibilities for treating chronic pain."

Science 1999;284:1979-1981.
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