August 14, 2007

Studying the Placebo Effect

The August 3 episode of ScienceFriday featured an interview with Columbia psychology professor Tor Wager about his research on the placebo effect. Wager and his team use fMRIs and PET scans to study how the use of "special creams" affects pain (high heat placed on skin). They first established where this kind of pain shows up in fMRIs. Then, in Wager's words, "... we put a cream on [subjects'] skin and we say this is lidocaine. It's an effective - it's a known pain reliever. We want to see how it works in your brain. So then we give them the same stimulus, the same hot, you know, hot plate on their arm, instead of a level eight, maybe it's a level six."

And later: "We find that some of the pain responsive regions of the brain actually showed decreases in activity when you have the placebo."

Finally, Wager states: "I think one of the sort of important and interesting take-home message is is that medical science has really, so far, ignored, to a large degree, people's beliefs and expectations, and pharmacology ignores it. But, in fact, because beliefs cause chemicals to be released in your brain, those chemicals actually can combine with drugs and do things that just the drugs themselves won't do."

For More Info
* ScienceFriday, August 3, hour two. Interview with Tor Wager, Assistant Professor, Department of Psychology, Columbia University. Transcript avaialable in LexisNexis. ScienceFriday also links to lots of other interesting stuff on the placebo effect, including an article from a 2004 issue of Scientific American: Scientists See How Placebo Effect Eases Pain and a 2007 episode of NYC's Radio Lab called simply Placebo

* Wager, Tor and team. Cognitive and Affective Control Laboratory @ Columbia University.

*Benedetti, F., Mayberg, H. S., Wager, T. D., Stohler, C. S., & Zubieta, J. -. (2005). "Neurobiological mechanisms of the placebo effect." Journal of Neuroscience, 25 (45), 10390-10402.
* Wager, T. D. (2005). "The neural bases of placebo effects in pain." Current Directions in Psychological Science, 14 (4), 175-179.
* Wager, T. D., Rilling, J. K., Smith, E. E., Sokolik, A., Casey, K. L., & Davidson, R. J. et al. (2004). "Placebo-induced changes in fMRI in the anticipation and experience of pain." Science, 303(5661), 1162-1167.
(citations retrieved from Scopus)

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