Entry 381, on 2006-08-17 at 15:46:38 (Rating 1, Science)
About one year ago New Scientist published a list of "13 things which don't make sense". I found the document lurking in my temporary folder today and decided to have another look at it. There's some really interesting stuff there. Here's the list of 13 things: the placebo effect, the horizon problem, ultra-energetic cosmic rays, Belfast homeopathy results, Dark matter, Viking's methane, Tetraneutrons, the Pioneer anomaly, dark energy, the Kuiper cliff, the Wow signal, the not-so-constant constants, and cold fusion.
I might comment on each of these in future blog entries, but I thought I might mention the first one here. First, this is the classic placebo experiment. Several times a day, for several days, they induced pain in subjects, which they controlled with morphine until the final day of the experiment, when they replaced the morphine with saline solution (which has no real effect). Surprisingly, the saline takes the pain away. That result has been known for years, but now things get really weird.
When Fabrizio Benedetti of the University of Turin in Italy carried out this experiment, he added a final twist by adding naloxone, a drug that blocks the effects of morphine, to the saline. The incredible result was that the pain-relieving power of saline solution disappeared.
What's going on here? The saline has no biochemical action, and its presumed to be the classic "mind over matter" placebo effect which resulted in it working. In other words, the subject thought it would work, so it did. But why would a biochemical blocker stop the action of something that isn't there? This is just bizarre, and a classic example of why experiments on humans have to be so tightly controlled. I found the subtlety of this type of experiment fascinating when I studied experimental psychology many years ago.
I don't know if further research has been done on this since then. Maybe the result was caused by a subtle experimental bias of some type, or maybe the link between the brain and body is more complex than we thought. If anyone reading this has heard anything further please leave a comment.
Comment 1 by Jim on 2006-08-24 at 22:54:38:
Huh? That really is very strange. If anyone out there knows anything more about this I would like to know more about it too!
Comment 2 by Kim on 2007-02-05 at 14:52:12:
Couldn't it be because the natural endorphins that were creating the placebo effect (ie: that were stopping the person from perceiving pain) were being blocked by the biochemical blocker? The answer is probably that the biochemical blocker wasn't blocking nothing - it was blocking the action of whatever natural brain chemicals that were being released by the individual to block the pain. (isn't that how placebo works for pain?)
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