Picturing The Placebo Effect

Doctors have long thought the placebo effect is all in the head, and it turns out they may be right. Using functional magnetic resonance imaging, which captures differences in blood flow in the brain, researchers have produced the strongest evidence yet of how the placebo effect works. In a study conducted at the Ann Arbor Veterans Affairs Health System, the University of Michigan and Princeton, the subjects were given harmless but frequently painful electric shocks and then provided with what they were told was a pain-relieving cream. After the bogus cream was applied, nerve activity in the brains of the volunteers changed. The prefrontal cortex, involved in easing pain, became more active, while regions involved in sensing pain quieted down. When it comes to feeling less pain, it seems, you gotta believe.

--By Alice Park