Ghost experiments 12.11.2014

Common sense tells us that there are no ghosts, and you can only meet them on the pages of a book, or in a movie, or in a computer game. At the same time, there is a sufficient amount of evidence about "real", "real" ghosts: people say that they saw, heard or simply felt "something like that." Among such testimonies there are quite scientific, medical cases - as you know, epileptics and patients with schizophrenia are distinguished by their sensitivity to ghosts. And this suggests that "spiritual vision" has a specific neurophysiological mechanism.

In 2006, Olaf Blanke, a specialist in cognitive neurophysiology from the University of Geneva (Switzerland), discovered that direct electrical stimulation of certain areas of the brain can "cause a ghost": it will seem to a person that someone is standing behind him, even if he is fully aware that no one can be there. (Let us explain that the experiments were carried out on patients with epilepsy who were to undergo surgical treatment. Before the operation, electrodes are implanted into their brains, with the help of which they recorded the activity of different parts of the brain - in order to find out exactly where epilepsy "hides" and how exactly it behaves. Such a method treatment has already been of great service to neuroscientists, since it is possible to study in parallel the most diverse aspects of the human brain, as is usually done in animals.)

The area of ​​the brain that was stimulated to "summon ghosts" was responsible for coordinating various sensory signals coming from outside. To better understand the mechanism involved, Olaf Blanke and his colleagues at the Federal Polytechnic School of Lausanne (Switzerland) compared brain damage in two groups of neurological patients. In the first, there were predominantly epileptics who felt the ghosts "in an explicit way", as something next to them. Patients from the second group spoke only about hallucinations and increased symptoms of the disease, but they did not feel someone's unknown presence (the main sign of a ghost). It turned out that those who saw, or rather, felt ghosts, had damage in the fronto-parietal cortex, which controls movement and simultaneously coordinates sensorimotor signals from the body. For example, the sound from a punch and the pain from it are brought together into a single picture with cause-and-effect relationships precisely thanks to the fronto-parietal cortex.

The researchers suggested that damage here distorts ideas about one's own body: sensorimotor impulses turn out to be inconsistent with each other, and therefore, for example, it may seem to us that someone is not us! stroked our hands. To test the hypothesis, a special robot was created, with the help of which it was possible to make an ordinary, healthy person feel a ghost next to him. The robot consisted of two "hands", one of which was placed in front of the person, and the second behind. The "hand" in front was, in fact, a control panel with which you could move the back "hand" - it was designed to poke a volunteer in the back. A video of the experiment can be viewed here.

The participant of the experiment, blindfolded and wearing headphones (so that he would not be distracted by extraneous stimuli), had to move the front "hand" of the robot with his finger, which sent a signal to the back "hand" that touched the person behind the back here and there. Volunteers were told that a robot would touch them from behind, but the movements of the back "hand" sometimes occurred with a delay of half a second, and only the experimenters, but not the experimental ones, knew about it. In an article in Current Biology, the authors write that as long as the movements of the robot's arms were synchronized (that is, the back arm accurately responded to the movements of the finger on the front arm), everything was fine: the person felt as if he was touching himself. But as soon as there was a delay, a ghost effect appeared: it began to seem to the person that there was someone else behind him who was touching him on the back, and this was not a robot. The effect was so frightening that some even asked to stop the experiment. However, it is worth saying that not everyone felt the "ghost", but only a third of the volunteers.

Then they set up another experiment similar to the previous one, only now the participants in the experiment were told that the experimenters themselves could approach them from time to time, but they would not touch them. In reality, no one approached the experimental subjects; they, in turn, had to say how many people are next to them at one time or another. And so, if the rear lever acted with a delay, then the person was much more likely to believe that someone was next to him (we emphasize: the volunteers knew that they would not touch them, but would only stand nearby), and the number of "neighbors" reached four.

That is, apparently, the appearance of ghosts can really be explained by the fact that the brain cannot coordinate the data from our own body, and in order to explain some sensory signals, some extraneous entities have to be involved. Here it is worth emphasizing that we are talking about the sensation of something or someone else, but not about visual hallucinations. The authors of the work believe that their data will help to understand the nature of some common symptoms of schizophrenia (and other complex neuropsychiatric diseases), when the patient feels someone's presence and obeys the will of someone who, as it seems to him, is nearby, or hears some voices .