Image: Scott Camazine/Photo Researchers, Inc.
Amputees who experience phantom limb pain can sometimes get relief from an optical illusion. This trick involves looking in a mirror at the reflection of a healthy limb from a certain angle, which causes it to appear where the missing limb should be. Seeing the limb move freely fools the brain into relieving the pain. Now a study suggests this technique might also work for arthritis pain.
Cognitive scientist Laura Case, working in the lab of Vilayanur S. Ramachandran (a member of Scientific American Mind’s board of advisers) at the University of California, San Diego, used a modified version of the mirror technique to superimpose a researcher’s healthy hand over a subject’s arthritic hand, which was painfully constricted or contorted. Subjects mimicked the slow, purposeful movements of the researcher’s hand with their own unseen hand. After experiencing the illusion of their hand moving smoothly, subjects rated their arthritis pain slightly lower than before and had an increased range of motion.
The result suggests that the toxic soup of inflammatory molecules bathing an arthritic joint is not the only source of painful sensations. “The brain has learned to associate movement with pain,” says Case, who presented her results at the Society for Neuroscience meeting last November in Washington, D.C. The illusion provides the brain with a way to disconnect the sight from the sensation. Next, the group will investigate whether this type of mirror therapy might provide long-term benefits for arthritis, a condition that affects about 50 million Americans.
This article was published in print as "Brain Trick Relieves Pain."
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6 Comments
Add CommentSeems like a possible Placebo effect to me...
Reply | Report Abuse | Link to thisThis is another headline grabbing piece of pseudoscience from the laboratory of V.S. Ramachandran. Laura Case made a poster presentation at a meeting. She cautioned that this was a preliminary pilot study involving only a few subjects. None-the-less this faux science news made its way across the internet and around the globe. At this point there is no published data. This is a trick that the Ramachandran lab has used before and they will use again. This report is more science fiction than science.
Reply | Report Abuse | Link to thisRemember that the Placebo Effect is real. There is real science demonstrating a statistical significance in the Placebo Effect. Perhaps, rather than brushing this kind of study off as a fake anomaly, scientists can study how powerful an effect it is and whether it can be used for pain management.
Reply | Report Abuse | Link to thisThe placebo effect is part of real science. However, most of the ideas that Ramachandran has presented about mirror therapy are not backed up by the research data. Certainly, Ramachandran has not presented any new scientific research on this subject since the early 1990s. The most recent evaluations of mirror therapy by pain researchers such as Lorimer Moseley and Herta Flor have shown that mirror therapy may provide modest pain relief when it is used in conjunction with other therapies such as graded motor imagery. None-the-less Ramachandran continues to make extraordinary claims for it on his own web site. Claims that are not supported by any credible research.
Reply | Report Abuse | Link to thisYes, the Placebo effect is real - it's important that it be recognized rather than inventing new processes to explain its effects.
Reply | Report Abuse | Link to thisif a genuine effect why does not the good hand immitate the bad one half the time?
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