In this Eric Mead keynote the mentalist and magician discusses the tendency for people to react in a real way to things that are fake. Sugar pills have been documented to have a measurable effect on the human body when advertised as a pharmaceutical drug. Individuals taking the pill claim to feel something and do produce results that indicate a change is happening.
Other qualities come into effect as well in terms of the placebo effect. Pills can have the exact same ingredients, none of which are pharmaceutical, but those that are smaller, painted blue and have a small letter on the outside have more of an effect than pills that don't. The most extreme case is needles; the imagery associated to hypodermic medications is so strong that something fake becomes something real because of someone's perception of it.
Eric Mead uses the science behind the placebo effect in order to dazzle audience members by inciting a physical reaction to an illusion that they know is fake, illustrating the power of interpretation and reception.