Acute pain is eased with touch of a hand

There may be a very good reason that people naturally clutch their hand after receiving an injury. A new report shows that self-touch offers significant relief for acute pain under experimental conditions. Researchers from UCL Institute of Cognitive Neuroscience suggest that the relief comes from a change in the brain's representation of the rest of the body. The research was published online on 23 September 2010 in Current Biology.  "Pain is quite an important, but also complicated, experience and can be caused in many different ways," said Professor Patrick Haggard from UCL Institute of Cognitive Neuroscience. "We show that levels of acute pain depend not just on the signals sent to the brain, but also on how the brain integrates these signals into a coherent representation of the body as a whole." Haggard and his colleague Marjolein Kammers, also at UCL, made the discovery by studying the effects of self-touch in people who were made to feel pain using an experimental condition known as the thermal grill illusion (TGI). "The TGI is one of the best-established laboratory methods for studying pain perception," Haggard explained. "In our version, the index and ring fingers are placed in warm water and the middle finger in cold water.