While the results were encouraging, Mackey wondered if, "We just designed the world's most expensive placebo," referring to the phenomenon where people report feeling better when they believe they are being treated, even if the "treatment" is fake. He added, "Let's face it, you've got an extraordinarily high-tech environment. You've got this big, expensive MRI system that's making all sorts of noise. We're telling people to go into this scanner and to control their brain activity and then with that we expected that there may be some change in how they perceived pain."
Mackey's team re-ran the experiments taking parts of the feedback chain away. One group got pain control instructions, but without the MRI scanner. A second got instructions and were inside the MRI scanner, but got no real time feedback. A third were told to observe in real time a part of the brain not involved in pain processing. A fourth, control group, underwent the process while watching someone else's brain activity.Mackey says of all those groups, "The only session… where they were able to learn how to control their own brain activity and see a change in their pain was with that real-time moment-by-moment information."
Not everyone was successful. Mackey says there were people who "were not significantly able to change their brain activity. And what we found is that they were also the people who tended not to be able to have significant control over their pain."
Those who suffer from chronic pain should not expect to see this method used for pain control anytime soon. In addition to being very expensive, Mackey says that right now the technology is, "not ready for prime time as a clinical treatment."
For one thing, they need to study the mechanism of exactly what went on for this control to happen. Mackey says, "People were just able to learn how to do it and that's what we're actually studying right now, is to figure out how they were able to do what they do."
In addition, they need to study the long-term benefits of this technique. He says, "We're running the studies right now."
But, what the study does show is what role the brain plays in determining what is or isn't painful. As Mackey puts it, "It's not pain until it hits your brain."
This research was published in the December 13, 2005 issue of Proceedings of the National Academy of Sciences and was funded by the National Institutes of Health, the Oxnard Foundation, the Dodie and John Rosekrans Pain Research Fund, and the Stanford University Department of Anesthesia.