Scientific American’s wonderful weekly podcast 60-Second Psych aired a fun episode back in October reporting on the British Psychological Society’s survey of 23 world-renown scientists. The BPS asked them all one question, which was published in the 150th issue of its research digest: “What is one nagging thing you still don’t understand about yourself?”
60-Second Psych has summarized some of the most interesting answers in its episode, “What the Experts Still Don’t Know.” Even at 180 seconds, it’s very much worth listening to—Susan Blackmore admitted to being perplexed by consciousness, Alison Gopnik by parenthood, David Lavallee by sporting rituals, Robert Sternberg by career masochism, and Richard Wiseman by wit, among others.
This topic reminded me of a NewScientist article back in 2005 about “13 Things That Do Not Make Sense.” The list includes cold fusion, the Kuiper cliff, and dark energy. At number one: the placebo effect.
Don’t try this at home. Several times a day, for several days, you induce pain in someone. You control the pain with morphine until the final day of the experiment, when you replace the morphine with saline solution. Guess what? The saline takes the pain away.
This is the placebo effect: somehow, sometimes, a whole lot of nothing can be very powerful. Except it’s not quite nothing. When Fabrizio Benedetti of the University of Turin in Italy carried out the above experiment, he added a final twist by adding naloxone, a drug that blocks the effects of morphine, to the saline. The shocking result? The pain-relieving power of saline solution disappeared.
So what is going on? Doctors have known about the placebo effect for decades, and the naloxone result seems to show that the placebo effect is somehow biochemical. But apart from that, we simply don’t know.
Benedetti has since shown that a saline placebo can also reduce tremors and muscle stiffness in people with Parkinson’s disease. He and his team measured the activity of neurons in the patients’ brains as they administered the saline. They found that individual neurons in the subthalamic nucleus (a common target for surgical attempts to relieve Parkinson’s symptoms) began to fire less often when the saline was given, and with fewer “bursts” of firing – another feature associated with Parkinson’s. The neuron activity decreased at the same time as the symptoms improved: the saline was definitely doing something.
We have a lot to learn about what is happening here, Benedetti says, but one thing is clear: the mind can affect the body’s biochemistry. “The relationship between expectation and therapeutic outcome is a wonderful model to understand mind-body interaction,” he says. Researchers now need to identify when and where placebo works. There may be diseases in which it has no effect. There may be a common mechanism in different illnesses. As yet, we just don’t know.
NewScientists followed-up with another list: “13 more things that don’t make sense,” including something called the nocebo effect, which is, “How a diagnosis of terminal illness can come true – even if it’s wrong.”