One of the National Public Radio programs I enjoy is “Hidden Brain,” so when I heard that host Shankar Vedantam had a well-reviewed new book, I went out and bought a copy. Titled “Useful Delusions: The Power & Paradox of the Self-Deceiving Brain,” it tells tales that are remarkable, incredible (as in hard to believe), and sometimes horrifying.
Take, for example, the case of surgeon Bruce Moseley at a VA Medical Center in Texas. He had served as the surgeon for the NBA’s Houston Rockets, had a remarkable track record, yet he had long questioned the efficacy of a common procedure, arthroscopic knee surgery. He wondered if the procedure itself, the mechanical scraping of residue in the knee joint, had a benefit, or if the actual benefit was derived from the saline wash used during the procedure. He devised a study, and a colleague convinced him to add a third group, a control group that got the incisions, but had neither the actual scraping nor the saline wash. It was not easy to get a study like this approved, but it eventually was, and Moseley found enough patients willing to be randomly assigned into the three study groups.
After two years, patients in all three groups reported marked levels of improvement. And there was no difference between those who received the actual procedure, those who only received the saline wash, and those who had what was, in truth, placebo surgery. Let me say that again. The outcome was exactly the same for those who had the traditional procedure, mechanical scraping of residue in the knee joint, those who only had the knee joint flushed with saline, and those who had incisions made on their knee with no actual procedure.
This is a particularly stunning example of something we know as the placebo effect. Now, if you are like me, you tend to associate placebos with hypochondriacs and the gullible. After all, you and I are way too smart to ever be duped in this way. But are we?
Continue reading “Placebo : 8 May 2022”