Various studies have been produced, recreating the effects of the ouija board in the lab and showing that, under laboratory conditions, the subjects were moving the planchette involuntarily. A 2012 study found that when answering yes or no questions, ouija use was significantly more accurate than guesswork, suggesting that it might draw on the unconscious mind. Skeptics have described ouija board users as 'operators'. Some critics noted that the messages ostensibly spelled out by spirits were similar to whatever was going through the minds of the subjects. According to professor of neurology Terence Hines in his book "Pseudoscience and the Paranormal" (2003):