British researchers from the University College London wanted to shed some light on how the brain processes pain.
Eighteen volunteers had one of their hands prodded with a hot probe and used mirrors so they could actually see the probe.
“We found, in our experiments, that people feel less pain when they look at their body than when they look at a neutral object in exactly the same location,” said Patrick Haggard, a professor of cognitive neuroscience at University College London.
“So the next thing, which was perhaps even more surprising, was to change the visual appearance of the body and see whether that further changed pain levels.
When scientists used a concave mirror to make the hand the volunteer thought was feeling the pain look larger, the pain threshold increased.
They then made the hand look smaller, and found that the volunteer felt more pain.
Cognitive neuroscientists are trying to figure out how this could be.
The study, published in the journal Psychological Science, seems to have come up with a number of conflicting findings.
“The one I find interesting is that … the person who’s got acute pain, the effect they get increases when they enlarge the vision of the affected limb,” said Professor David Crewther from Swinburne University, who is also involved in the study.
“It decreases when they minify the view of the limb. Possibly different systems are being stimulated here in terms of pain.”
It is hoped that with further research, this study could help come up with better ways to manage pain.
“In the meantime, the authors of the study suggest that when a child feels pain or is about to get a needle from a doctor, this time they should not look away.
The findings suggest they should look at the arm that is in pain, but that they should try to avoid looking at the needle if that is at all possible.