A couple years ago, my little brother called me into his room and begged me to try on his new video game headset. This wasn’t any old gamer headset—it was virtually a portal to another world. I’m a baby so, of course, I denied his request at first. But then he talked me into fitting the machinery onto my head… and I was immediately transported. What were previously white walls and normal bedroom décor became the wide-open ocean water. There was now a shipwreck directly in front of me, fish swimming leisurely to my left, and the reflection of sunshine directly above me. I smiled in amazement, happy I listened to my kid-brother for once—but then a humongous shark whipped past me and I screamed. Needless to say, the virtual reality headset ended up across the room.
I was amazed by how realistic this virtual world appeared. It was as if I could outstretch my arms and touch the fish, search the shipwreck, and swim to the surface far above me if I wanted to. And this was just a game—not the most advanced or best use of virtual reality technology in the world. ‘I wonder where this invention will take us’, I thought to myself. ‘It could become something really amazing.’ Not to toot my own horn, but I was right. A new breakthrough study from EPFL, Switzerland, which will be published in Neurology, shows that with the help of virtual reality, phantom body pain in paraplegics can be reduced.
Paraplegics are paralyzed from the waist down. They can’t move or feel anything below the waist, usually due to a spinal cord injury that resulted from a disease or accident; sometimes, however, they do experience phantom pain, which is a mysterious aching that originates in the numb or amputated extremities. This pain is very real, yet it has been widely misunderstood and mistreated for years. Thanks to this research, individuals who experience this pain may finally receive some relief through the restoration of their sense of touch—thanks to virtual reality.
This experiment involved the use of dummy legs, virtual reality goggles, a camera, and two rods. The dummy legs were first filmed by a camera and then the video was displayed on the virtual reality goggles worn by the paraplegic participants. These participants then watched the dummy legs from above on their goggles—as if they were looking down at their own two legs—while a scientist tapped their back with one rod and their dummy legs with the other. There were therefore two stimuli in this test: the tapping on the paraplegic’s back and the visual from the virtual reality goggles. Now, despite knowing they were being tapped on the back, these participants felt it in their paralyzed legs.
“We managed to provoke an illusion: the illusion that the subject’s legs were being lightly tapped, when in fact the subject was actually being tapped on the back, above the spinal cord lesion,” explains Olaf Blanke, neuroscientist and leader of the study. His colleague goes on to explain how this was possible: “This is because the subject also received visual stimuli of dummy legs being tapped, viewed through the virtual reality headset, so the subject saw them immersively as his or her own legs,” says Polona Poeg, co-author of the study.
Here, virtual reality is used to carry out conflicting stimuli and, in turn, relieve phantom pain. “The tapping on the back gets translated onto the legs because the visual stimulus dominates over the tactile one,” explains Blanke. It ultimately manipulates the brain and provides the participants with a sort of virtual therapy—which these very researchers are building on right now for people with spinal cord injury and other chronic pain conditions.
Source: EPFL “Virtual Reality Reduces Phantom Pain in Paraplegics.” NeuroscienceNews. NeuroscienceNews, 30 October 2017.