This Is What It Feels Like to Be Invisible

Remember that time when you felt so embarrassed you just wanted to disappear? Now researchers over in Sweden have pitted that idea in science. In a st​​udy published today in Nature, they explore how the state of invisibility can make people feel less anxious when they're subject to the gaze of others.

Invisibility might seem like the stuff of science fiction, but recent advances in material science research hints that it might not be long before we're actually decking ourselves out in invisibility cloaks. In March 2014, researchers at the University of Central Florida made a breakthr​ough discovery in which they pe​rfected a nanotransfer printing technique that made it possible to make larger amounts of metamaterial, which could mask fighter jets. And China's been all over th​e idea for years.

But, according to researchers at the Group Ehrsson, Br​ain, Body and Self Laboratory in Sweden, what's been less explored is how the embodied experience of being invisible might alter the way we mentally perceive our bodies. The point is, what if we get to deck ourselves out in an invisibility kit but end up with issues because we can't see ourselves as existing, and find that too strange to cope with?

To examine the issue, the research group, headed by PhD student Arvid Guterstam, recruited 125 volunteers and used virtual reality to conjure up the illusion of an invisible body for each participant. Each volunteer wore a mounted VR headset that projected the illusion of an empty space, each time they glanced down at their bodies. The experimenter—wielding a paintbrush in each hand—made the same motions onto the participant's body with the paintbrush and the space in front of them, which was first occupied with a mannequin, then left empty. A camera overlooking both the mannequin and the empty space fed the images of the moving paintbrush into the participant's VR headset. This conjured the illusion that the participant was seeing the mannequin's body, or the empty invisible body as their own.

"When the touches are synchronised in time and space with the brush strokes in empty space, the brain automatically merges the visual and tactile input that precedes the sense of touch as occurring in empty space," Guterstam told me. "As a consequence, the brain draws the conclusion that your body is invisible."

Guterstam explained that the first part of the experiment was to establish if participants would be taken in by the illusion of the invisible body. Once it was established that the illusion worked, the researchers tested if the feeling of being invisible affected "cognitive functions such as the processing of social cues." For this, the researchers created a fictional stressful situation, where they subjected the participant's mannequin, then invisible body to a hypothetical onlookers—in this case, a crowd of scientist onlookers.

"We created the illusion of having a mannequin's body, then an invisible body [for each participant]. Then after one minute, the participant looked up and realised that they were standing in front of an audience of strangers," said Guterstam.

The researchers measured the participants heart rates in each of the mannequin body versus invisible body situations. They found that stress levels were higher when the participants physical mannequin body had been subjected to the gaze of onlookers. So their conclusion? It definitely helped out in high pressure social situations, if you were invisible.

Next up, the researchers want to examine if this technique can be applied in treating social anxiety. Guterstam told me that the leading non-medical treatment for this condition is cognitive behavioural therapy (CBT). It aims to expose the patient to very low stress situations first, then gradually increase the level of stress so that the patient can habituate their response.

"As a first initial step in CBT, we want to create the idea of [the patient] being an invisible body, standing in front of an audience," said Guterstam. He explained that the idea would be to gradually decrease the transparency of the patient's body in the virtual setup, until the patient's body in the virtual setting reached an opacity which paralleled the visibility of their real world body.​