I find it helpful to think of the human body as an interface. It is, after all, the thing that connects our brain with the outside world. But do not take this to mean that I do not consider the body important! It’s sensors and effectors influence the way we perceive the world and how we are able to act upon it. As such, it is intimately intertwined with who we are.
The interesting thing is, of course, that the body is not static. It changes – every day when yours hair grows, over time when you become taller, fatter or skinnier, and sometimes traumatically when an accident happens. This means your brain also has to be flexible about what belongs to your body and what not.
A quite well-known example of this is the rubber hand illusion. Used as a parlor trick for many years, it was studied more closely in 1987 by Botvinick and Cohen. Basically, you hide a person’s real hand (under a table or behind a sheet) and instead place a rubber hand on top of the table, where normally the hand would be. Then you stroke the hidden real hand and the rubber hand at the same time. If you are nice, you’ll ask the person after a minute or so whether the rubber hand feels like their own. If you’re mean, you grab a mallet or a knife, hit/stab the rubber hand, and watch them pull their real hand back in shock.
The rubber hand illusion works still if the hand is a different skin-color from the person – even if it’s a non-human color, like purple. Against all evidence to the contrary and despite an embodied experience of many years, your brain is apparently perfectly comfortable with deciding that a purple hand is completely normal and part of your body, nothing to see here, move along. As long as two senses agree that the hand seems part of you (in this case vision and touch), it works. It’s not ‘only’ psychological either: the body reacts to the shock of hitting the rubber hand with a release of adrenaline, and even a heightened immune system activity in the ‘affected’ hand.
This strange flexibility has been studied further using full-body illusions. Virtual reality techniques have made it possible for quite some years now to put a person inside of a complete virtual body. You can also track their movements and make sure the virtual body is moving in the same way, thus invoking a similar embodiment illusion.
There were two particularly interesting studies in 2013. In the first, by Peck, light-skinned participants were placed in a dark-skinned virtual body for a few minutes. They did some movement exercises in front of a virtual body, and experienced an embodiment illusion, feeling that the virtual body was their own. The trick was that they had been tested on implicit racial bias before the illusion, and afterwards they were tested again. In just a few minutes, their unconscious bias went markedly down. It is very, very difficult to change someones (or even your own) implicit racial bias, as it is an unconscious process. But a few minutes in a virtual body seems to do it, if only temporarily.
In the second study, by Banakou, participants were placed in a child-like virtual body, and similar effects were found – the experience had a profound psychological effect. After the illusion, people misjudged object sizes as bigger, and displayed more child-like behavior and personality.
It seems that embodiment illusions can work as a kind of ‘point-of-view gun’. The Machine to be Another makes artworks that explore this: a performer wears a camera on their head while an audience member wears a virtual reality headset, showing the view of the camera. The performer tries to match the movements of the audience member as well as possible, thus creating an illusion that ‘ transplants’ the audience inside of the body of the performer.
But apart from possibly generating empathy, embodiment illusions can also change our personality. A study by Rosenberg and others in 2013 had participants experience flying in virtual reality – either freely, as if their body itself could fly, or in a virtual helicopter. Afterwards, a scientist would walk in the room and drop a bunch of papers and books. Participants who had the virtual experience of flying without any aid where much more helpful than the ones who had flown in a helicopter.
A study by Osimo and others in 2015 asked participants to switch bodies during the experiment – reflecting the two-chair experiment in Gestalt therapy, a person first explained a small social problem to another virtual avatar, then switched to that avatar, heard their own explanation back, and gave themselves advice. Then they switched back to the point of view of the first body and listened to the advice. The second body looked different between conditions: in the first it was a self-similar body, looking like the participant., but in the second the body was modeled to look like Sigmund Freud, an expert who people perceive as capable of giving good psychological advice. And what happened? Participants who gave themselves advice from the Freud-body thought their advice was much better!
The implication of this are multifold. There are many ways and different fields in which the embodiment of an expert can be useful – even if it would only boost your confidence!
So how about going into that physics exam after being Einstein for a few minutes? You only need a phone, a headset, and the right app.
Lisa Evelyn 