Robots create 'ghosts' in room

A team of researchers have successfully developed a robot that is capable of giving otherwise healthy people the "feeling of a presence", simply by sending mixed-up sensorimotor signals to the brain.

The main motive behind the research was to know where that "feeling of a presence" (FoP) phenomenon comes from.

Lead researcher Olaf Blanke said that in their first experiment with the robo], thirty percent of the healthy participants spontaneously reported the feeling of having somebody behind them, touching them.

The robot made the participants of the study feel as though they were reaching out in front of them and touching their own backs. When the robotic stimulation was asynchronous with the individual's own body movements, something rather remarkable happened: people felt, in some cases very strongly, as though there were another person standing behind them, touching them and individuals also felt as though their bodies drifted backward in space, toward this mysterious, other presence, and judged that there were more people in the room.

The researchers explain that the spatiotemporal conflict was resolved by their participants by generating the illusory experience that the felt touch was not caused by themselves, but by another person behind them who was touching their back.

The authors concluded that the present neuroimaging and robotics data provided a solid scientific explanation for the FoP and link a phenomenon that appears at first sight as strange and complex to basic mechanisms of sensorimotor signal integration in a cortical network centering in frontoparietal cortex and a prominent account of positive symptoms in schizophrenia.

The study is published in Cell Press journal Current Biology.