Research Highlights
Brain Scans Show How Placebo Eases Pain
April 1, 2004
Researchers have produced the strongest evidence yet that placebo-or the mere expectation of
relief, with no real treatment-causes physical changes in how the brain responds to pain. In
related studies at the Ann Arbor VA Medical Center and two universities, scientists 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 anti-pain cream had been applied to their arm, they rated the pain as less
intense-and the pain circuits in their brain showed less activity. Doctors have long recognized
the power of placebo to make patients feel better, but this was the clearest proof yet of actual
changes in the brain's pain pathways.
Placebo-induced changes in FMRI in the anticipation and experience of pain.
Wager TD, Rilling JK, Smith EE, Sokolik A, Casey KL, Davidson RJ, Kosslyn SM, Rose RM, Cohen
JD.