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Scientists Used Virtual Reality to Teleport People into Different Bodies

How to tell how much you relate to another body? Threaten it with a sledgehammer and see if you flinch.

This article originally appeared on Motherboard

While surgery bots like Da Vinci XI are already letting doctors perform surgery through machines, we could see humans teleoperating robots from greater distances in the future. Say, for example, a doctor in London operating on someone in Mumbai, or a human operating a robot on Mars. But what goes on in your brain when you’re under the illusion of embodying a robot?


In a study published today, researchers at Sweden’s Karolinksa Institute set out to answer that question by creating an out-of-body illusion where volunteers were "teleported" into a foreign body with the help of virtual reality headsets. Brain activity was then measured as they experienced this illusion.

“This experiment is a brain imaging experiment. We’re interested in the brain mechanisms that give rise to the feeling that you’re inside your body,” said co-author of the study and cognitive neuroscientist Henrik Ehrsson over the phone.

In the experiment, 15 volunteers were asked to lie on the bed inside a MRI scanner. They wore VR headsets through which they saw a stranger’s body—also lying in the same room—being stroked by a paintbrush, while the same actions were performed on their own body. This technique was similarly used in an earlier "phantom limb" experiment, where a participant’s real hand was stroked at the same time as adjacent empty space (an “invisible hand”), leading them to feel that the invisible hand was actually part of their body.

According to lead author of the study, Arvid Guterstam, the brain merges the sensation of touch and visual input from the new perspective in a matter of seconds. This results in the illusion of “owning the stranger’s body and being located in that body’s position in the room, outside the participant’s physical body,” he said in a press statement.


Ehrsson told me that the group were interested in uncovering two things. “We firstly asked how the brain creates this experience of accepting this new, stranger’s body as your own,” he said. “Secondly, we wanted to see which part of the brain gives rise to the feeling that you’re are located in a particular place.”

To investigate how people experienced body ownership and location in space, Ehrsson and his team “teleported” the volunteers between different locations in the experiment room, with the help of the mounted VR headsets. For instance, for one part of the experiment, the volunteer viewed him/herself from another location in the room, and witnessed various hypothetical threat situations—such as being hit by a spoon or sledgehammer, or threatened with a knife—both on their VR and real body. The researchers measured the participant’s reactions and found that stress levels increased when the participant’s VR body was threatened, but not when they saw their real body at risk.

The researchers assessed brain activity while the volunteers were either inside the MRI scanner, and under the illusion that they were owning someone else’s body. The pattern recognition techniques used to analyse brain activity revealed that activity patterns in the hippocampus, posterior cingulate retrosplenial, and intraparietal cortices corresponded with a sense of being in a specific location. And premotor-intraparietal activity was associated with the sense of owning a body. The aim of all this was to work out what was happening in the brain when the volunteer either felt they owned a body, or sensed they were in a new location.


This image shows brain regions relating to participants' perceived self-location. Image: Malin Björnsdotter/Arvid Guterstam

Previous studies in rats have revealed that certain regions of a rodent’s brain (the hippocampus) contain compass-like “place cells”, which allow it to understand its position in a room. This discovery, made by neuroscientist John O’Keefe, was awarded the 2014 Nobel Prize.

Place cells are recognised as being involved in navigation and memory encoding, but the researchers at Karonlinska wanted to take this understanding to another level. “In our experiment, we wanted to see if activities in these place cells are related to conscious feeling, or the direct experience that you are located in a certain place,” said Ehrsson, who noted that the group’s study found that the human brain experiences a similar phenomenon to the rats. Their findings revealed that along with being involved in navigation and memory encoding, place cells are also important for producing the conscious experience of existing in a location.

Next, the group want to apply their research to virtual reality research and remoted-controlled teleoperated robots. “In our experiment, we are teleporting the sense of self into a stranger’s body. But that body could be a robot that could even perform surgery over a long distance,” added Ehrsson.


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