This Is Why Your Brain Thinks It Can Feel Nearby Spirits

Neuroscientists explain how the brain creates that feeling of a ghost.

Most Popular
Advertisement - Continue Reading Below

You know that supernatural feeling that a ghost, angel, or spirit is nearby? A robot can now create that, according to the neuroscientists behind a new study, who hope their findings could help researchers discover why people experience these "presences."

The scientists investigated 12 patients with neurological disorders such as epilepsy, strokes, tumors or migraines, and who experienced these invisible presences for anywhere from seconds to minutes. Brain scans revealed this feeling to be linked to damage in any of three brain regions: the temporoparietal, insular, and especially the frontoparietal cortex. These areas integrate sensorimotor signals—ones that involve both the sensory system and the motor system responsible for movements.

Most Popular

As they report in their new study in Current Biology, the scientists though that confusion over the source and identity of such signals might cause the feeling of a presence, with people wrongly attributing their own bodily signals or movements as coming from beyond the body. To test their idea, they built a robot to confuse the senses.

The scientist had 17 healthy volunteers stand blindfolded between two robots: a "master" robot in front of them, causing a "slave" robot behind them. When the people moved their arms, they moved the master robot in front of them, causing the robot behind the volunteers to stroke the people on the backs. When these robotic strokes were synchronized with the motions of the volunteers, the people experienced the illusory feeling of reaching out in front of themselves and touching their own backs. But when the scientists messed with them by delaying these strokes a half-second, five volunteers felt a presence—an experience disconcerting enough that two of participants wanted to stop the experiment.

"We have a clear explanation of a very complex hallucination," says study lead author Olaf Blanke, director of the Center for Neuroprosthetics at Ecole Polytechnique Fédérale de Lausanne in Switzerland.

Cognitive neuropsychologist Chris Frith, an emeritus professor of neuropsychology at University College London in England who did not take part in this research, came away impressed: "At first thought, the feeling that someone is just behind you when there is no one there seems utterly mysterious and outside the domain of science," he says.

"Nevertheless, Blanke has shown that this feeling has very specific neural underpinnings. Furthermore he has shown, using advanced robotic equipment, that it is possible to create the experience in normal volunteers in controlled lab conditions. This makes me much more optimistic that other strange experiences, such as those reported by patients with schizophrenia, can also be explained using his approach."

More from Popular Mechanics: