Man walking past invisible bodies. Photo: Getty Images
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Scientists suggest invisibility as a cure for anxiety

Neuroscientists have made the surprise discovery that the sensation of invisibly reduces responses to anxiety.

Have you ever felt fear and anxiety from standing in front of a large audience and giving a speech? Or how about having to get up in class and talk to other students? While it's normal in situations like these to wish for the ground to swallow you up, some scientists have suggested a slightly different remedy for anxiety - invisibility.

Invisibility has long featured in myths and fiction, but several advances in material sciences have demonstrated that the cloaking of large (living) objects - just like how the invisibility cloak works in Harry Potter - is becoming a realistic prospect. In the field of material sciences, the general concept of invisibility cloaking is actually fairly simple.

Theoretically, all that's needed is a material that guides visible light (or another wave, like EM waves or heat fluxaround an object, and anything within the gap it leaves will be rendered "invisible" to someone standing at the light source:

Light moves around the object (or person) as though it isn't there. Image: Trevor Johnston/trevorjohnston.com

In practice, this is hard to achieve, as most naturally occurring materials reflect light, cast shadows and produce a reflection. However, hi-tech and exotic materials called "metamaterials" have made light bending possible. (Although latest research suggest that ordinary lenses can do just the trick!)

H G Wells, a man ahead of his time, wrote the The Invisible Man in 1897. The novel is about a protagonist who invents a method to change the human body’s refractory index to that of the air, rendering it invisible. (The twist comes when he performs the method on himself and can’t reverse it - but that’s beside the point.) The refractive index is the ratio between how light passes through a vacuum, and how it passes through any other medium; it’s the reason a spoon will look bent when placed in a glass of water. If water has a negative refractive index, the spoon would look as though as was bending back on itself instead.

In a recent paper in Scientific Reports, graduate students Arvid Guterstam and Zakaryah Abdulkarim and their advisor Henrik Ehrsson, a neuroscience professor at the Karolinska Institutet in Stockholm, said they believe invisibility cloaking of the human body is a thing of the future, and believe it’s high time we delve into what it feels like to be invisible.

To do this, Guterstam, Abdulkarim, and Ehrsson used virtual reality. In one of their experiments, 23 people were provided with a set of head-mounted displays (HMD), and were asked to look at their feet. The experimenter - Abdulkarim - stroked their arms, legs, and torso with a paintbrush with one hand, and at the same time, made identical motions with a second paintbrush with the other hand, on an invisible body or a mannequin. A pair of downward-facing cameras that were either mounted on a tripod or on the head of a mannequin sent a real-time video feed to the participants HMDs, giving them the sensation of being invisible, or making a body swap with a mannequin:

Study co-author Zakaryah Abdulkarim (middle) creates the invisible body illusion on a participant (left) wearing a set of head-mounted displays connected to a pair of cameras. Photo: Staffan Larsson

Here's the surprise: after finishing with the paintbrush, each participant slowly lifted their gaze through their HMDs to find that they were being watched by a scornful-looking audience (consisting of 11 scientists instructed to stare at the participant). Quite creepy, and perhaps enough to through most people off - however, on a 100-point scale, participants reported their stress level as about 25 per cent lower, on average, when in a state of invisibility, and about a third less than in the mannequin version. The state of invisibility also lowered heart rates by a few beats per minute, suggesting that stress is intertwined with physiology.

The researchers write: “Our results demonstrate that healthy individuals can experience the illusion of owning an invisible full body." They suggest their results could spur on better a design for virtual-reality based therapies for social anxiety, and may also help give neuroscientists gain new insight into phantom limb illusions.

Tosin Thompson writes about science and was the New Statesman's 2015 Wellcome Trust Scholar. 

Photo: Getty
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The internet dictionary: what is astroturfing?

Yes, like the fake grass.

Thanks to the internet, there are a lot of new words. You’re most likely up to speed with your LOLs and OMGs, which became Oxford English Dictionary-worthy in 2011 (LOL OMG if you’re not). But words emerge constantly, and it can be hard to keep track of them. This is what this column is for. Every week, I’ll define a word that is crucial to understanding the internet, starting with “astroturfing” – like the fake grass.

To astroturf is to mask the author of a message to make it appear to have come from the grass roots. Messages created by brands, politicians and even the military are disguised as comments made by the public. The practice existed before the web – the term is thought to have been coined in 1985 by a US senator who received a “mountain” of letters from insurance companies posing as the public – but the internet has propelled it to new, disturbing heights.

“GIRLS U NEED TO READ THIS,” reads a tweet by a handsome teenage boy named Ashton, who tweets the same words day after day, followed by crying and heart emojis. Ashton lives to promote the book of a 19-year-old self-published author from Sheffield – or, at least, he would, if he lived at all. Ashton is fake, a profile designed to make the book seem popular. Many teenage girls have been duped by this. One told me: “I felt very cheated out of my money and my time.”

It has been estimated that a third of all consumer reviews online are fake. But it doesn’t end with bad books. In China, the “50 Cent Army” are astroturfers who are allegedly paid a small fee for each positive post they write about the Chinese Communist Party. And in 2011, it emerged that the US military was developing an “online persona management service” to spread pro-American messages, allowing one person to manage multiple online identities.

We would be foolish to assume that our own democracy is immune. Much was written about how the Tories used targeted social media adverts at the last election, and it is easy to see how astroturfing could transform our political landscape for ever. 

Amelia Tait is a technology and digital culture writer at the New Statesman.

This article first appeared in the 10 August 2017 issue of the New Statesman, France’s new Napoleon