February 10, 2011

Reduce Pain By Looking At It

A study published today in Psychological Science, examines how the brain processes pain and concludes that what you look at can influence how much pain you feel.

Contrary to many people's compulsion of looking away during a painful event such as an injection, scientists found that looking at your body - in this case the hand - reduces the pain experienced, BBC News reports.

Researchers also showed that magnifying the hand to make it appear larger cut pain levels further still. The team says that gaining a better understanding of this could lead to new treatments.

Eighteen volunteers helped The University College London (UCL) and University of Milan-Bicocca research, which was funded by the Biotechnology and Biological Sciences Research Council (BBSRC). The study included the application of a heated probe held in each participant's hand with the temperature gradually increased. When this began to feel painful, the probe was removed and the temperature noted.

Patrick Haggard, professor of cognitive neuroscience from UCL, tells BBC News: "This gives us a measure of the pain threshold, and it is a safe and reliable way of testing when the brain pathways that underline pain become active."

Scientists then used mirrors to manipulate what the volunteers saw during the study. The team found that volunteers could tolerate on average 3C more heat when they were looking at their hand in the mirror, compared with when their hand was obscured by a block of wood.

"You always advise children not to look when they are having an injection or a blood sample taken, but we have found that looking at the body is analgesic - just looking at the body reduces pain levels," Professor Haggard says. "So my advice would be to look at your arm, but try to avoid seeing the needle - if that's possible."

Researchers in another experiment used convex mirrors to enlarge the appearance of the participant's hand. In doing so, the volunteers were able to tolerate higher temperatures. Conversely, when the team made the volunteers' hands look smaller, their pain threshold decreased.

"Pain is an enormous problem in the National Health Service and in society generally," Dr. Paul Nandi, a consultant in pain medicine at UCL Hospitals' Pain Management Centre, tells BBC News. "We do not have precise figures, but it affects several million people in the UK, and it has a huge impact on quality of life.

"It also produces a huge economic burden - if you look at chronic back pain alone, it is estimated that it costs £16bn per annum. But this is still widely under-appreciated, and hasn't received the same attention and resources as other areas perceived as "Ëœexciting' in the medical profession."

Dr. Nandi continues by stating that studies like this could help to drive more research. "A lot of research in the past few years has focused on identifying targets in the nervous systems that can be used for treatments. But increasingly there is an interest in what the brain does to pain signals, and I think this will be a very exciting field for research in the next few years." 


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