Natalya "Natasha" Nikolayevna Demkina (Russian: Ната́лья Никола́евна Де́мкина; born 1987 in Saransk, Mordovia) is a Russian woman who claims to possess a special vision that allows her to look inside human bodies and see organs and tissues, and thereby make medical diagnoses. Since the age of ten, she has performed readings in Russia. She is widely known by the childhood variant of her given name, Natasha.
In 2004 she appeared on television shows in the United Kingdom, on the Discovery Channel and in Japan. Since 2004 Demkina has been a full-time student of the Semashko State Stomatological University, Moscow. Since January 2006, Demkina has worked for the Center of Special Diagnostics of the Natalya Demkina (TSSD), whose stated purpose is to diagnose and treat illness in cooperation with "experts possessing unusual abilities, folk healers and professionals of traditional medicine."
According to her mother, Tatyana Vladimovna, Demkina was a fast learner, but was otherwise a normal child until she was ten years old, at which time her ability began to manifest itself.
- "I was at home with my mother and suddenly I had a vision. I could see inside my mother's body and I started telling her about the organs I could see. Now, I have to switch from my regular vision to what I call medical vision. For a fraction of a second, I see a colorful picture inside the person and then I start to analyze it." says Demkina
After describing her mother's internal organs to her, Demkina's story began to spread by word of mouth among the local population and people began gathering outside her door seeking medical consultations. Her story was picked up by a local newspaper in spring 2003 and a local television station followed suit in November that year. This led to interest from a British tabloid newspaper which invited her to give demonstrations in London, as well as further invitations from groups in New York and Tokyo.
After stories about Demkina had begun to spread, doctors at a children’s hospital in her home town asked her to perform a number of tasks to see if her abilities were genuine. Demkina is reported to have drawn a picture of what she saw inside a doctor’s stomach, marking where he had an ulcer. She also disagreed with the diagnosis of a cancer patient, saying all she could see was a small cyst.
United Kingdom 
In January 2004, British tabloid newspaper The Sun brought Demkina to England. She gave a number of demonstrations and her diagnoses were then compared to professional medical diagnosis. A Discovery Channel documentary on Demkina mentions reports of Demkina having successfully identified all the fractures and metal pins in a woman who had recently been a victim in a car crash. The Guardian reported that she impressed the host of daytime television program This Morning by spotting that she had a sore ankle during an interview.
Initially, Demkina's demonstrations were well received. However, after she had left the United Kingdom, it emerged that she had made errors among her diagnoses. In one incident she told television-physician Chris Steele that he was suffering from a number of medical conditions, including kidney stones, an ailment of the gall bladder, and an enlarged liver and pancreas. Later medical evaluation determined that he was in good health and was not suffering from any of the ailments she had identified.
New York 
In May 2004 she was brought to New York City by the Discovery Channel to appear on a documentary titled The Girl with X-Ray Eyes, and to be tested by skeptical researchers from the Committee for Skeptical Inquiry (CSI) under partially controlled conditions.
As a demonstration for the documentary, Demkina was shown wearing her vision-hat and giving diagnoses to people who had previously given descriptions of their specific medical conditions. Most of the people given these readings felt that Demkina had accurately identified their conditions. The researchers, however, were not similarly impressed. CSI researcher Richard Wiseman said, "When I saw her do her usual readings, I couldn't believe the discrepancy between what I was hearing and how impressed the individuals were... I thought they were going to walk away saying it was embarrassing, but time and again, they said it was amazing. Before each reading, I asked the people what was the main medical problem and Natasha never got one of those right." Wiseman compared the belief of people in Demkina's diagnoses to the belief of people in fortune tellers, and said that people focus only on those portions of Demkina's comments that they believe.
Then CSI researchers Ray Hyman and Wiseman, and Andrew Skolnick of the now defunct Commission for Scientific Medicine and Mental Health (CSMMH) conducted their test of Demkina. In the test, Demkina was asked to correctly match six specified anatomical anomalies to seven volunteer subjects. The cases in question included six specified anatomical anomalies resulting from surgery and one "normal" control subject. The researchers said that, because of limitation in time and resources, the preliminary test was designed to look only for a strongly demonstrated ability. The researchers explained that while evidence of a weak or erratic ability may be of theoretical interest, it would be useless for providing medical diagnoses. In addition, the researchers said that the influence of non-paranormal observations could not be ruled out under the lax conditions of the test. Demkina and the investigators had agreed that in order to warrant further testing, she needed to correctly match at least five of the seven conditions. In the 4-hour-long test, Demkina correctly matched conditions to four volunteers, including the control subject. The researchers concluded that she had not demonstrated evidence of an ability that would warrant their further study.
Subsequently, the design and conclusions of this experiment were subjects of considerable dispute between Demkina's supporters and those of the investigators.
Demkina's criticism 
After completing experiments in New York, Demkina made several complaints in regard to the conditions under which they were conducted, and about the way in which she and her diagnoses were treated. She argued that she had required more time to see a metal plate in one subject's skull, that surgical scars interfered with her ability to see the resected esophagus in another, and that she had been presented with two study subjects who had undergone abdominal procedure, but that she had only one abdominal condition on her list of potential diagnoses, leaving her confused as to which one matched the listed condition.
She also complained that she could not see that one volunteer had had their appendix removed because she said appendixes sometimes grow back. She said she was not able to compare her own diagnosis to an independent medical diagnosis after key experiments had been conducted, preventing her from being able to see if she was diagnosing genuine conditions that were unknown to those conducting the experiments, and which were thus being listed against her in the overall results despite them being valid (due to this complaint, all volunteers in the Tokyo experiments were required to bring medical certificates with them before diagnosis).
In response to these complaints, the research team stated that Demkina should have been able to find the plate without extrasensory abilities, because its outline could be seen beneath the subject's scalp, and questioned why the presence of scar tissue in a subject's throat had not alerted her to them having an esophagal condition. Additionally, they noted that it remains clinically impossible for an appendix to spontaneously regrow.
Brian Josephson's criticism 
In a self-published commentary regarding the New York testing performed by CSICOP and CSMMH, Brian Josephson, a Nobel Prize-winning physicist and the director of University of Cambridge's Mind-Matter Unification project, criticized the test and evaluation methods used by Hyman and questioned the researchers' motives, leveling the accusation that the experiment had the appearance of being "some kind of plot to discredit the teenage claimed psychic."
Stating that the results should have been deemed "inconclusive", Josephson argued the odds of Demkina achieving four matches out of seven by chance alone were 1 in 50, or less than 2% – making her success rate a statistically significant result. He also argued that Hyman used a Bayes factor that was statistically unjustifiable because it greatly increased the risk of the experiment falsely recording a moderate correlation as being no correlation.
Hyman responded that the high benchmark used in the testing was necessary due to the higher levels of statistical significance required when testing paranormal claims (extraordinary claims requiring extraordinary proof), and that a high Bayes factor was necessary to compensate for the fact that "Demkina was not blindly guessing", but instead "had a great number of normal sensory clues that could have helped increase her number of correct matches".
Bayes factors are used to compensate for variables that cannot be calculated through conventional statistics; in this case, the variable created by the visual clues that Demkina might gather from observing a subject. The Bayes factors used by Hyman were calculated by professors Persi Diaconis and Susan Holmes of the Department of Statistics at Stanford University.
According to accounts on her personal website, after her experiences in London and New York, Demkina set several conditions for the tests, including that the subjects bring with them a medical certificate stating their health status, and that the diagnosis be restricted to a single specific part of the body–the head, the torso, or extremities–which she was to be informed of in advance.
Demkina's website claims that she was able to see that one of the subjects had a prosthetic knee, and that another had asymmetrically placed internal organs. She also claims to have detected the early stages of pregnancy in a female subject, and an undulating spinal curvature in another subject.
Machi also arranged for a test to take place in a veterinary clinic, where Demkina was asked to diagnose an anomaly in a dog. Natasha claims to have correctly identified that the dog had an artificial device in its back right leg after being specifically directed to look at the animal's paws.
As with the test conducted in the UK, the Tokyo tests were not subject to independent review.
- "Special Diagnostic Center of Natalya Demkina". – Archive copy at the Wayback Machine
- The Discovery Channel, 2004, The Girl with X-Ray Eyes, (Wayback Machine)
- The Guardian, 25 Sept 2004, "Visionary or fortune teller? Why scientists find diagnoses of 'x-ray' girl hard to stomach"
- Skolnick AA, Skeptical Inquirer, May 2005, "Testing Natasha: The Girl with Normal Eyes"
- Hyman R, Skeptical Inquirer, May 2005, "Testing Natasha"
- Hyman R, CSICOP, "Statistics and the Test of Natasha"
- Josephson, Brian. "Scientists' unethical use of media for propaganda purposes". Retrieved 2006-08-31.
- "Scientists fail to see eye to eye over girl's 'X-ray vision'". Times Higher Education Supplement. December 10, 2004.
- Hyman, Ray. "Statistics and the Test of Natasha". CSICOP. Retrieved 2010-02-05.
- Commission for Scientific Medicine and Mental Health (CSMMH), "Answer to Critics"
- Mathworld Bayesian Analysis
- "Cause, Chance and Bayesian Statistics: A Briefing Document". Retrieved 2006-09-11.
- Hyman, Ray (Sept/October 2005). "Statistics of the Natasha test: response to concerns and questions". Skeptical Inquirer. Retrieved 2007-02-02.