The Power of the Mind and the Phantom Hand

Such stuff as dreams are made on—William Shakespeare

Vilayanur S. Ramachandran and Diane Rogers-Ramachandran at the Center for Brain and Cognition at the University of California in San Diego conducted an incredibly illuminating experiment on mind and perception (reported in the Premiere issue of Scientific American Mind, Feb 2005).

Briefly, the experiment involved a subject whose right hand was concealed from her while a fake plastic right hand was placed in full view. The experimenter repeatedly tapped or stroked the person’s concealed hand, while simultaneously doing the same to the plastic hand. After half a minute the person whose concealed hand was being stroked began to feel the fake hand being stroked! “The sensations seem to emerge directly from the plastic rather than from [the person’s] actual hidden flesh,” reported Ramachandran and Rogers-Ramachandran. This illusion was first reported by Matthew Botvinick and Jonothan Cohen at the University of Pittsburgh in 1998; they suggested that look and proximity of the fake hand to the hidden real hand was enough to fool the brain.

But there’s more.