Researchers use virtual reality gear to mess with subjects’ perspective
If you think about it, memory is an astounding thing. At will, our brains can dig back through the archives and pull out the sights, sounds, smells, sensations, and emotions from a day long gone. All those memories have one pretty obvious thing in common—everything about an experience is recorded from a first-person perspective. But what happens if your memory is not in first-person.
Some people go through what is commonly referred to as “out-of-body experiences,” where they feel a sense of detachment from their body as if they were somehow floating above it. This and related “dissociative” phenomena can be a part of posttraumatic stress disorder or schizophrenia, for example. The people who have out-of-body experiences often seem to have difficulty recalling these experiences with the usual amount of detail. That could be a clue about how our memories work, but how could you design an experiment to test the possibilities?
Loretxu Bergouignan and Henrik Ehrsson of Sweden’s Karolinska Institute and Umeå University’s Lars Nyberg have an answer. They utilized a setup that simulates the feeling of an out-of-body experience by transporting a subject’s perception of sight and sound across the room. (Science writer Ed Yong has first-hand knowledge of this non-first-person experience.) Subjects wear a virtual-reality-like display connected to stereo cameras and microphones that can be placed elsewhere. Under controlled conditions (holding still, etc.) the illusion can be quite profound.
In order to test the effect this has on memory, the researchers staged situations intended to be memorable. The participants—64 university students—were given some reading materials on several topics and told they would be given an oral exam. After they studied up, they donned the virtual reality gear. The cameras were placed in a few different configurations: either just above and behind the student’s head to match a normal perspective, on the opposite side of the room pointing back at themselves, or a few feet to their right. To reinforce the out-of-body illusion, one person walked up to the cameras and repeatedly extended a rod toward a point below them while another poked the student’s actual chest synchronously.
At this point, a professional actor playing the role of an “eccentric professor” entered the room, sat in a chair facing the student, and began to . . .