Synesthesia describes the experience that some people have, where the stimulation of one sense results in other senses being stimulated. For example words take on different colours and may create a sensation of certain smells. A recent study by Milán et al. (2012) found that many psychic healers who claim to see the aura of their patients are actually synesthetes. This condition would explain why they think they may be able to heal people, however it doesn’t explain why seeing an aura would lead to healing. The occasional success of psychic healing may be explained in terms of a placebo effect.