Experiment shows how mind can create ghosts when stressed

Telegraph : When someone reports having seen a ghost, it may really be just a figment of the imagination, according to a recent study published in Current Biology. Researchers in Switzerland set up a robot system, in which the human subjects used their index finger to control the movements of a master robot. Those movements were relayed to a slave robot located behind the human subjects that touched their back. That sensation alone felt weird enough to the test subjects, but it became stranger still when a delayed reaction was introduced between the subjects touching the robot button and their backs being touched. Then the subjects reported feeling as if they were being watched and touched by invisible people. The researchers say that the phenomenon occurs when the functioning of the human brain gets disrupted, which can happen when subjected to such conditions as illness, extreme cold, oxygen deprivation, or exhaustion. Two of the 12 participants were so upset by the experiment that they asked that it be stopped.