If you’ve ever been to a magic show, you know how easy it is to “trick” your brain into seeing something that isn’t quite there.
Now, a new study published in the journal Pain Reports has unveiled an effective but unusual illusion that has exciting implications for pain management.
The researchers were exploring a phenomenon known as the Rubber Hand Illusion (RHI) — which involves placing a fake hand on a table in front of someone while their real hand is hidden from view.
Scientists have previously found that when both hands are temporarily brushed at the same time, many participants begin to experience sensations in the rubber hand as if it were part of their body.
In this new study, the researchers used heat and light instead of touching — 34 participants were presented with a rubber hand that glowed red while their actual hand, hidden behind a screen, received heat at various temperatures that ranged from pleasant to painful.
Participants used their other hand to rate their levels of pain and — in the control group — the rubber hand was flipped upside down.
What they found was that — when the rubber hand was facing right side up — participants reported less pain as quickly as 1.5 seconds into the illusion and the effect continued as long as the illusion went on.
“We showed that the perceived pain intensity was reduced in the rubber hand illusion condition compared to the control condition,” lead author Martin Diers, a professor of Psychosomatic Medicine and Psychotherapy at Ruhr University Bochum in Germany, said in a statement.
“The findings suggest that when people perceive the rubber hand as part of their own body, this reduces their perception of pain.”
The study sheds fascinating insight into the way the brain’s integration of visual and sensory information can be manipulated to alleviate pain.
Another reason the illusion is so successful may be due to visual analgesia — a studied phenomenon in which simply looking at a body part that is in pain reduces your perceived intensity of that pain.
However, Diers noted that “we still don’t fully understand the neural basis for this phenomenon.”
Still, their findings could potentially pave the way for some non-pharmaceutical alternatives for treating chronic pain — and that’s a relief in itself.
