Department of Psychiatry at Cambridge University designed experiments to investigate treatment methods for schizophrenia. Like schizophrenics who sometimes believe that external objects have become part of their body, injection of ketamine – an anesthetic agent also produces similar feelings. Ketamine is a hallucinogenic drug.
The team injected 15 participants with ketamine before testing whether it made them more or less likely to identify a false rubber hand as their own. Ketamine made subjects more likely to believe that the fake hand was their own. The participants were healthy young volunteers who took part for the monetary compensation (£250).
Authors write, “In the rubber-hand illusion, synchronous tactile and visual stimulation lead to the experience that a rubber hand is actually one’s own… This illusion is stronger in schizophrenia. Given the evidence that ketamine reproduces symptoms of schizophrenia, we sought to determine whether the rubber-hand illusion is augmented by ketamine… We studied 15 healthy volunteers in a within-subjects placebo-controlled study. All volunteers carried out two versions of the rubber-hand task, each under both placebo and ketamine infusions… Ketamine was associated with significant increases in subjective measures of the illusion and in hand mislocalization…Ketamine mimics the perturbed sense of body ownership seen in schizophrenia, suggesting that it produces a comparable alteration in integration of information across sensory domains and in the subjective and behavioural consequences of such integration.”
John Mitchell, spokesman for Rehab Guide, an organization to help drug addicts said this experiment was a “dangerous game”. He said, “This is encouraging people to use ketamine for monetary reward. It’s immoral. That’s just a personal opinion but it’s a very dangerous game.”
The study was led by Professor Paul Fletcher and titles, “Exploring the Impact of Ketamine on the Experience of Illusory Body Ownership.” The findings were submitted to Biological Psychiatry in March this year, the official journal of the Society of Biological Psychiatry, and will be printed in the January 2011 edition.
Prof Fletcher in response to criticism said in a statement, “All participants undergo intensive screening beforehand, in terms of their history of physical or mental illness and of past drug abuse… We would not do this work if we considered that there was an unacceptable risk to participants.”