The Out-of-Body Electric
Can scientists make your soul fly away?
Two teams of neuroscientists have made a breakthrough in the study of "out-of-body experiences," according to this week's issue of Science. About one in 10 people report having had the strange sensation of floating away from their bodies at some point in their lives. According to the new studies, it's now possible to induce that feeling of astral projection in the lab.
There have been similar claims in the past: At Laurentian University in Canada, Michael Persinger has used a helmet studded with magnets to create quasi-mystical experiences, including—for some subjects, at least—the sensation of drifting outside the body. But the authors of the new research manage the feat without any neural poking or zapping. Instead, they use little more than a pair of virtual-reality goggles.
The new approach seems to work as advertised—test subjects said the experiment made them feel like they were outside of their own bodies. But that's where the story ends. The out-of-body VR setup does a great job of mimicking the superficial aspects of the out-of-body experience. But it teaches us very little about how or why it happens in real life.
The first of these studies, titled "The Experimental Induction of Out-of-Body Experiences" and conducted by Henrik Ehrsson, shows that you can create something like an OBE using special effects. First, you sit in a chair and don a pair of virtual-reality goggles that are connected to a 3-D camera that's pointed at the back of your head. Looking through these goggles already makes you feel, at least to some extent, as though you're where the camera is, sitting a few feet behind your own body. (It's possible to create a similar feeling of displacement without looking at your own head: If the goggles were showing a three-dimensional video feed of the bathroom, you might feel a bit like you were in the bathroom.)
Now, Ehrsson tries to make the effect more realistic. He starts rubbing your chest, while at the same time reaching a hand toward the camera that's providing the video feed. As you feel the touch on your chest, you're also seeing an arm reach below your video "eyes." This combination, it turns out, makes you feel even more like you're sitting behind yourself. (Likewise, if you were watching a video feed of the bathroom and the experimenter flushed a toilet, it would make you feel even more like you were in the bathroom.)
To measure the strength of this illusion, Ehrsson conducts one more test. About a minute into the experiment, he suddenly picks up a hammer and swings it toward the empty space just below your camera "eyes." At the same time, he measures your emotional arousal using skin conductance electrodes: The more realistic the experience, the more charged up you'll get at the sight of the hammer coming toward your virtual nose.
The study confirmed that synchronized touching makes the illusion more vivid. ("Wow!" giggled one subject. "I felt as though I was outside my body and looking at myself from the back!") If you saw Ehrsson rub your imaginary chest at the same time that you felt it happening, you'd be more startled when he swung the hammer. In fact, this "multisensory correlation" of vision and touch helps you figure out your position in space—and decide whether you're in body or out of body. (The second paper, by Bigna Lenggenhager and Olaf Blanke, uses a different setup to arrive at the same conclusion; click here for more details.)