Whether it's The Ring of Gyges, The Invisible Man, or The Lord of the Rings, literature has long been fascinated with the prospect of invisibility. Would we run around naked? Would we get lonely? Would we feel less anxious in front of crowds?
Science has yet to answer the first two questions, but it has finally tackled the third. The answer, according to a small new experiment: Feeling as though you're invisible—as in H.G. Wells-style see-through—seems to calm one's nerves in the otherwise unnerving experience of having a crowd of people stare at you.
You might wonder how science has managed to test the hypothesis that invisibility alleviates social anxiety. You may also be curious as to why anyone would bother. Regarding the latter: Improvements in cloaking technology—yes, that's a real thing—mean the time is nigh to consider the consequences of human invisibility, argue graduate students Arvid Guterstam and Zakaryah Abdulkarim and their advisor Henrik Ehrsson, a neuroscience professor at the Karolinska Institutet in Stockholm, Sweden in a paper out today in Scientific Reports.
Invisibility lowered heart rates by a few beats per minute, suggesting there may have been a physiological basis to the differences in stress.
Guterstam, Abdulkarim, and Ehrsson didn't use any of the high-tech (or low-tech) options for turning objects invisible. Instead, they relied on virtual reality to set up a freaky illusion. The researchers outfitted 23 people with virtual reality goggles and asked them to look down at their feet while an experimenter—Abdulkarim—stroked their arms, legs, and torso with a paintbrush. Meanwhile, Abdulkarim made identical motions with a second paintbrush in his other hand, either in mid-air or on a mannequin. A camera, aimed downward and mounted either on a tripod or on the mannequin's head, sent video to participants' goggles, giving them the impression of being invisible or of having swapped bodies with a mannequin.
The combined effect of touch (altered) vision and the mid-air version of the experiment was enough to make people feel transparent nearly to the point of invisibility, a previous test showed. But now, the team had a surprise: After finishing with the paintbrush, each person slowly lifted their heads, and, as they did, each saw in their goggles a group of stern, serious-looking people staring back at them.
That would probably be enough to throw most of us off, but it turns out invisibility eases things a bit. On a 100-point scale, participants reported their stress level as about 25 on average in the invisibility condition, about a third less than in the mannequin version. Invisibility lowered heart rates by a few beats per minute as well, suggesting there may have been a physiological basis to the differences in stress.
"Our results demonstrate that healthy individuals"—as opposed to those suffering some kind of mental illness—"can experience the illusion of owning an invisible full body," the team writes. They suggest the results could be used to design better virtual reality-based treatments for social anxiety, and may have implications for neuroscientists' understanding of phantom limb illusions as well.
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