Study Measures Brain Power In Easing Pain
Researchers Measure Physical Effects Of Placebo Power
POSTED: 3:20 p.m. EST February 19, 2004
WASHINGTON -- Brain power may have more to do with pain than we think.
Two brain-scanning studies published in the journal Science found that when it's time to feel better, thinking that a drug helps can make it so -- a finding that researchers say catches the power of placebo in action.
SURVEY
Do you believe in the power of the placebo effect?
Yes, absolutely.
There's something to it, but it's not that powerful.
No, it's a sham.
I don't know enough about it.
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In a study by the University of Michigan and Ann Arbor Veterans Affairs Health Care System, researchers used functional magnetic resonance imaging to map changes in blood flow in the brains of volunteers. The volunteers were subjected to harmless but occasionally painful electric shocks or heat. When they believed an antipain cream had been applied to their arm, they rated the pain as less intense -- and the pain circuits in their brain showed less activity.
Because doctors know the placebo effect is real, they talk up the benefits of a drug as they write the prescription. But the effect had been assumed to be psychological, without any actual physical effects.
Dr. Jon Levine, a pain specialist at the University of California, San Francisco, said these results show the placebo effect is actually due to a physiological weakening of the pain signal.
"We've shown what the old family doctor knew very well -- that his interaction with the patient made a great difference in the effectiveness of whatever treatment he was giving," said Dr. Kenneth Casey, a researcher on the study and a professor at the University of Michigan.
Another study published in the journal shows some of the same brain regions involved in feeling physical pain become activated when someone empathizes with another's pain.
Researchers from University College London studied pain-related empathy in 16 couples, under an assumption that couples are likely to feel empathy for each other. Brain activity in the woman was assessed while painful electrode stimulation was applied to her or to her partner's right hand.
They found that the partners who weren't actually feeling pain still had brain stimulation in the same areas of the brain as when they did feel the pain.
Science
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