By:
Wednesday, March 03, 2004

The research of Ed Smith and colleagues was published in the February 20 issue of Science magazine and is also in the following briefing from Time magazine.

Science

February 20, 2004

Placebo-Induced Changes in fMRI in the Anticipation and Experience of Pain

The experience of pain arises from both physiological and psychological factors, including one's beliefs and expectations. Thus, placebo treatments that have no intrinsic pharmacological effects may produce analgesia by altering expectations. However, controversy exists regarding whether placebos alter sensory pain transmission, pain affect, or simply produce compliance with the suggestions of investigators. In two functional magnetic resonance imaging (fMRI) experiments, we found that placebo analgesia was related to decreased brain activity in pain-sensitive brain regions, including the thalamus, insula, and anterior cingulate cortex, and was associated with increased activity during anticipation of pain in the prefrontal cortex, providing evidence that placebos alter the experience of pain.

---

Click to view the item on the Science website.

---

Time

Alice Park
March 1, 2004

Briefing: 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.

---

Click to view the article on the Time website.