Looking at your body can reduce pain

Looking at your arm as it's being vaccinated may lessen the pain, scientists claim.

Researchers from University College London and the University of Milano-Bicocca in Italy found that people were able to tolerate more pain if they looked at the part of the body experiencing the pain.

Dr Flavia Mancin, who led the study, explained: “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.”

The scientists reached their conclusion after applying a heat probe to the hands of 18 volunteers. The temperature of the probe was gradually increased, and the volunteers were able to stop the heat by pressing a foot pedal when they experienced pain.

They also used a set of mirrors to manipulate what the participants saw during the experiment.

Volunteers were able to tolerate 3°C more heat just by looking at the affected hand compared to looking at another object.

And when mirrors were used to make the hand look bigger, the participants tolerated higher levels of heat before reporting pain.

Conversely, when the hand appeared to be smaller than its actual size, the participants reported pain at lower temperatures - i.e. their pain threshold was reduced.

As the level of pain was dependent on how large the hand looked, the scientists said their findings suggest that the experience of pain arises in parts of the brain that represent the size of the body.

Professor Patrick Haggard at UCL 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!”

The findings are published in the journal Psychological Science.

This article was published on Fri 11 February 2011