Placebo effects have already been proven to work on the immune system. But this study could show for the first time that they work in a different way — that is, through an act of will. “As far as we know today, the placebo responses in the immune system are attributable to unconscious classical conditioning,” says the Italian neuroscientist Fabrizio Benedetti, a leading expert in placebo effects. In Benedetti’s experiments, a suggestion planted in the minds of test subjects produced physiological changes directly, the way a dinner bell might goose the salivary glands of a dog. (In one study, healthy volunteers given a placebo — a suggestion that any pain they experienced was actually beneficial to their bodies — were found to produce higher levels of natural painkillers.) “There’s no evidence that expectations play a role as well,” Benedetti says. Langer plans to further analyze the subjects’ saliva to see whether they actually have the rhinovirus and not just elevated IgA.
via New York Times
