A long, but very interesting read.....
Brain imaging is illuminating the neural patterns behind pain’s infinite variety.
Initially, I was concerned that I was letting the team down. The capsaicin patch hardly tingled, and I scored the first round of pinpricks as a 3, more out of hope than conviction. I needn’t have worried. The patch began to itch, then burn. By the time the hot-water bottle was placed on it, about an hour in, I was surely at an 8. The next set of pinpricks felt as if I were being run through with a hot metal skewer.
“You’re a good responder,” Tracey told me, rubbing her hands together, when I emerged, dazed. “And you’ve got a lovely plump brain—all my postdocs want to sign you up.” As my data were sent off for analysis, she pressed a large cappuccino into my hands and gently removed the capsaicin with an alcohol wipe.
Tracey didn’t need to ask me how it had gone. The imaging-analysis software, designed in her department and now used around the world, employs a color scale that shades from cool to hot, with three-dimensional pixels coded from blue through red to yellow, depending on the level of neural activity in a region. Tracey has analyzed thousands of these “blob maps,” as she calls them—scans produced using a technique called functional magnetic resonance imaging (fMRI). Watching a succession of fiery-orange jellyfish flaring up in my skull, she had seen my pain wax and wane, its outlines shifting as mild discomfort became nearly unbearable agony.