Look at your body to reduce pain
10 February 2011
Simply looking at your body reduces pain, according to new research by BBSRC-funded scientists from UCL (University College London) and the University of Milano-Bicocca, Italy.
The team has been studying the relationships between sensory experiences - touch or pain, for example - bodily actions such as movement, and how it is that the brain is able to modify actions and sensory processing based on our perception of our own body as distinct from external objects. By understanding the fundamentals of how our brains and bodies integrate in this way, we can appreciate the bioscience that underpins many elements of physical and mental wellbeing.
Published in the journal Psychological Science, this new research shows that viewing your hand reduces the pain experienced when a hot object touches the skin. Furthermore, the level of pain depended on how large the hand looked - the larger the hand the greater the effect of pain reduction.
Flavia Mancini, the first author of the study, said "The image that the brain forms of our own body has a strong effect on the experienced level of pain. Moreover, the way the body is represented influences the level of pain experienced."
During the experiment, 18 participants had a heat probe placed on their left hand. The probe temperature was gradually increased, and participants stopped the heat by pressing a foot pedal as soon as they began to feel pain. The scientists used a set of mirrors to manipulate what the participants saw during the experiment. Participants always looked towards their left hand, but they either saw their own hand, or a wooden object appearing at the hand's location.
The team found that simply viewing the hand reduced pain levels: the pain threshold was about 3°C higher when looking at the hand, compared to when looking at another object.
Next, the team used concave and convex mirrors to show the hand as either enlarged or reduced in size. When the hand was seen as enlarged, participants tolerated even greater levels of heat from the probe before reporting pain. When the hand was seen as smaller than its true size, participants reported pain at lower temperatures than when viewing the hand at its normal size.
This suggests that the experience of pain arises in parts of the brain that represent the size of the body. The scientists' 'visual trick' may have influenced the brain's spatial maps of the skin. The results suggest that the processing of pain is closely linked to these brain maps of the skin.
Professor Patrick Haggard said: "Many psychological therapies for pain focus on the painful stimulus, for example by changing expectations, or by teaching distraction techniques. However, thinking beyond the stimulus that causes pain, to the body itself, may have novel therapeutic implications. For example, when a child goes to the doctor for a blood test, we tell them it will hurt less if they don't look at the needle. Our results suggest that they should look at their arm, but they should try to avoid seeing the needle, if that is possible!"
Notes to editors
For more information or to interview Prof Patrick Haggard or Flavia Mancini, please contact the UCL Media Realtions Office (see external contacts below).
'Visual distortion of body size modulates pain perception' will shortly be published in Psychological Science. Journalists can obtain copies of the paper by contacting UCL Media Relations.
The researchers include:
- Flavia Mancini, University of Milano-Bicocca, Milan & Institute of Cognitive Neuroscience, UCL
- Matthew R. Longo, Birkbeck, University of London
- Marjolein P.M. Kammers, Institute of Cognitive Neuroscience, UCL
- Patrick Haggard, Institute of Cognitive Neuroscience, UCL
Founded in 1826, UCL (University College London) was the first English university established after Oxford and Cambridge, the first to admit students regardless of race, class, religion or gender, and the first to provide systematic teaching of law, architecture and medicine. UCL is among the world's top universities, as reflected by performance in a range of international rankings and tables. Alumni include Marie Stopes, Jonathan Dimbleby, Lord Woolf, Alexander Graham Bell, and members of the band Coldplay. UCL currently has over 13,000 undergraduate and 9,000 postgraduate students. Its annual income is over £700M. www.ucl.ac.uk
BBSRC is the UK funding agency for research in the life sciences. Sponsored by Government, BBSRC annually invests around £470M in a wide range of research that makes a significant contribution to the quality of life in the UK and beyond and supports a number of important industrial stakeholders, including the agriculture, food, chemical, healthcare and pharmaceutical sectors.
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- The Babraham Institute
- Institute for Animal Health
- Institute of Biological, Environmental and Rural Sciences (Aberystwyth University)
- Institute of Food Research
- John Innes Centre
- The Genome Analysis Centre
- The Roslin Institute (University of Edinburgh)
- Rothamsted Research
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Clare Ryan, UCL Media Relations Office
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