I’m lying in the plastic cocoon of an MRI machine, an instrument that measures activity in different parts of the brain. As I try to hold still, the loudly clanking machine runs a structural scan to locate the anterior cingulate cortex and the insula, regions involved in processing pain. A computer then translates the MRI signal into three small animated fires, representing the activity levels of the cingulate and the right and left insula, projected onto a screen above my face.
I concentrate to make those fires roar and ebb, using only my thoughts. As I do, the MRI is measuring changes in the blood flow to selected parts of my brain. The patterns of blood flow tell the computer how neural activity is changing. By trying to control the size of the fires, I am attempting to control brain activity in the cingulate and insula, and in turn to quell the chronic back pain that has irked me in recent years.
Monitoring my progress is Christopher deCharms, a neuroscientist and founder of Omneuron, a startup company in Menlo Park, CA. DeCharms has spent the last five years developing imaging techniques that can be used to teach patients to control their brain activity. Changes in neural activity usually take place unconsciously, as different parts of the brain are engaged to perform tasks or process stimuli. Neurons in the language circuit start firing, for example, when you have a conversation with a friend. When you watch a scary movie, neurons in the amygdala, an area involved in emotion, fire more frequently. But consciously controlling these changes – damping activity in specific brain regions – could theoretically be useful for treating not only pain but such diseases as depression or even stroke. Exerting that kind of control is difficult, but it may offer an alternative to drugs that is both more precise and less likely to cause side effects.
Until a few years ago, selective control of brain activity was just a provocative idea. But a new version of functional magnetic resonance imaging (fMRI) has, for the first time, made brain activity visible in real time. The technology was just what deCharms needed. He and his collaborator Sean Mackey, associate director of the Pain Management Division at Stanford University, have already shown that their technique works, at least in the short term. In December, they published the results of their first study in the journal Proceedings of the National Academy of Sciences, showing that both healthy subjects and chronic-pain patients could learn to control brain activity – and pain – using real-time fMRI.
“There are potentially dozens of diseases of the brain and nervous system caused by an inappropriate level of brain activation in different areas,” says deCharms. He cautions that fMRI feedback is not yet ready for clinical use – he and Mackey are still confirming their results in long-term clinical trials. But even as he refines the use of the technique for treating pain, deCharms is now testing it in patients with anxiety disorders. And other scientists are running or planning pilot studies of fMRI feedback to treat depression, stroke, attention deficit hyperactivity disorder (ADHD), and post-traumatic stress disorder.