Affect of presence

Virtual reality can be made quite convincing. It needs a simple trick

Before starting work, American psychologist Kathleen Armel from the University of California asked students not to make sudden movements. At first it was not difficult: having seated another volunteer at the table, the woman began to tap her fingers on his hand. Several minutes passed like this - the young man calmed down and stopped paying attention to these actions. And then the psychologist with a sharp movement twisted the student's fingers.

Armel's experience looked brutal, but no one was actually hurt. The psychologist flexed her fingers on the rubber limb, which lay in front of the subject. He did not see his real hand - it was hidden by a partition on the table. But the volunteers still experienced stress - they instantly forgot about the instructions and, like scalded ones, pulled their hand away. “You could see in their eyes that they were scared,” Armel recalls. “Then a lot of people laughed nervously.” And two particularly impressionable students even assured her that they really felt pain.

The secret of the focus is simple. Touching the dummy, the psychologist simultaneously touched her wards by the living hand hidden from the eyes. A couple of such movements - and the illusion arose that the dummy is the hand. Seven years ago, Armel proved that most people fall for such a trick, and more recently, practical applications have been found for such illusions. In an experiment by Mel Slater of University College London, a computer-simulated character played the role of a rubber dummy. By touching the shoulders of people traveling in virtual reality, the scientist made them feel like they were in the body of fictional characters. Perhaps this technology will soon be used in medicine.

GIRLS LIVING ONLINE

Participants in Slater's experiment had to change gender - of course, virtually. Twenty-four men put on special glasses and saw the world through the eyes of a little girl. They moved into a small room. There was a table, a wardrobe, a sofa in it, toys were scattered around, and a fire burned in the fireplace. But most importantly, there was a huge mirror in the room, in which one could see the reflection of one's "avatar".

The volunteers had little time to explore the premises - they were not alone there. An adult woman stood nearby, whose behavior was controlled by a computer program, and the participants in the experiment looked up at her. At some point, the woman began to shake the girl by the shoulder, and Slater simultaneously did the same with his wards. This went on for a long time - the scientist waited until an illusion appeared in their brain and they began to feel their virtual bodies.

Then the woman removed her hand, and the participants in the experiment decided that they were left alone. But then the virtual girl suddenly received a resounding slap in the face - the men heard this sound well in the headphones. Soon the woman struck two more blows. Volunteers watched this scene no longer through the eyes of a child, but from the side. “My colleagues and I thought it would be too cruel to force the participants of the experience to look at all this in the first person,” says Slater. During the first strike, his volunteers seemed to fly out of the child's body, hovering under the ceiling. “The trick with moving everyone was very impressed,” the scientist recalls. “One person confessed to me that it was a mystical experience - as if the soul suddenly left the body.”

However, before flying up to the ceiling, the men still managed to get quite frightened. They told Slater that the sight of a woman about to slap her face gave them the most genuine fear. The scientist did not need such confessions - he monitored the level of stress with the help of a heartbeat sensor.

Slater decided to make sure that it was the feeling of touch that made people feel comfortable with virtual characters, and repeated the experience with a new team of volunteers. This time, the scientist touched their shoulder inappropriately - at those moments when nothing of the kind happened to the virtual body. This time, the participants of the experiment were not afraid of a slap in the face. This scene for them was no scarier than a cartoon.

CURE FOR PHOBIAS

For those who fell under the influence of such an illusion, it was not possible to quickly dispel it. How this can be, was shown in his experiment by the discoverer of the “rubber hand” effect, psychologist Matthew Botvinik from the University of Pittsburgh. First, the scientist showed the volunteers this trick, which has become a classic, and then asked them to perform another, very simple task. Closing their eyes, the participants in the experiment touched the fingers of their right hand to their left hand, for which they had recently taken the dummy. Not everyone got it right the first time. It was no coincidence that people missed - their fingers themselves stretched a little more to the left than they needed to, to where the rubber hand used to lie. “The existence of such illusions forces us to reconsider our ideas about how a person perceives himself,” Slater reflects. “The connection between the brain and the body turned out to be less strong than we could imagine.”

Slater's work has received rave reviews. “Recently, everyone has been doing nothing but creating the most complex virtual spaces possible. Finally, we started thinking about the travelers themselves,” says Swedish neurophysiologist Henrik Ersson, a well-known specialist in virtual reality.

He is sure that the transmission of tactile sensations is exactly what modern computer technology lacks. “So popular now social networks actually only alienate people from each other,” says Ersson. “Real communication is impossible without touch, the same handshakes.”

Slater agrees. He continues to improve his technique and has already come up with a way to automate his experiments. Now Slater uses devices that are attached to the body of a volunteer and at the right time create a sense of touch. “For now, I will keep quiet about what we are going to use all this for,” the scientist says. “We need to get patents first.”

One possible practical application is medicine. More and more researchers are considering using virtual reality to treat mental disorders. Psychiatrists at the Sainte-Marguerite hospital in Marseille want to use this technology to relieve people of claustrophobia. They are going to immerse patients in virtual reality, where people would gradually learn not to be afraid of closed spaces. If a person also feels touches (for example, walls in a tiny room), then training will become more effective.

Another such technology would not interfere with the Spanish psychologist Christina Botellier. She hopes to use it to treat her pathological fear of insects and spiders. Now its development looks like this: a person wearing special glasses sees how cockroaches begin to crawl over his body. For complete realism, there is not enough tactile sensations.