The Interpreter

摘要

Just before the holidays, Kenneth Casey's young granddaughter accidentally slammed the tip of her finger in a car door. Not surprisingly, she reacted quite strongly. Casey, a long-time pain researcher at the University of Michigan, had a look and saw there was little damage; he repeatedly reassured her that though it would hurt, she'd be OK. Very soon she calmed down. "It was amazing," says Casey of the change in her mood. Pain encompasses multiple components—sensory, cognitive, and emotional. The intensity of one's pain experience stems not only from the inner workings of biological pathways, but also from one's emotional state, expectations, and previous experiences. From nociception to transmission, the brain is the ultimate interpreter and modulator of the pain experience. Therefore, it's not surprising that researchers believed they'd found, in brain-imaging technologies, the ultimate tool to decipher the neural correlates of pain. Positron emission tomography in the 1980s, and later functional magnetic resonance imaging (fMRI) in the 1990s, promised to elucidate and greatly expand the intricacies of pain perception where electrophysiological recordings and lesion studies had fallen short.