Science-- there's something for everyone

Sunday, February 20, 2011

Reduced pain through body imagery

Here’s a result I did not expect to see: simply looking at the injured part of your body can reduce pain levels. This counterintuitive finding was exposed by Flavia Mancini and her colleagues at University College London.

Eighteen brave volunteers were fitted with a heat probe on their left hands. The heat was gradually increased until it became painful, at which point the participants could press a foot petal to stop the experiment. Although the subjects were all told to look toward their left hands, what they saw was controlled by a series of mirrors. Some people saw their own left hand, actual sized, some saw a wooden object in that position, and some saw their hand distorted to look larger or smaller.

People who saw their own hand could tolerate about 3°C higher temperature than those who had seen a piece of wood. Even more intriguingly, those who saw a reduced sized hand experienced more pain than those who saw a normal sized hand. The lucky ones who saw an enlarged hand could tolerate the most heat.

This goes counter to all the advice I’ve heard over the years about looking away during painful examinations or treatments. Instead, if this small study is to be believed, the better tactic would be to watch intently as your injuries are tended. In fact, whenever possible, patients should be given mirrors to enlarge the damaged area.