Pain is a simple enough concept to grasp. You stub your toe, shout, perhaps utter a few expletives, rub it better and it eventually fades. But neuroscientists are realising that pain is much more complex than anyone thought possible, comprising not just physical sensations, but emotional ones too. Pioneering studies are providing insights into why some people experience debilitating chronic pain long after an injury has healed, as well as why some are more prone to pain than others, and why certain people never recover from bereavement.
"Pain is much more than mere sensation. The psychological component is at least as important as the physiological processes giving rise to it," says Dr Jonathan Brooks, a scientist at the Centre for Functional Magnetic Resonance Imaging of the Brain, at Oxford University. His research centre scans the brains of people with chronic pain and compares them with those of healthy people.
While most pain goes away as an injury gets better, sometimes it remains for months or even years, long outlasting its original purpose.