Two New Illusions of the Tongue

Abstract

New illusions resulting from failures in proprioception are described. The Forked Tongue illusion results from weaving the tongue among the prongs of a fork, or from using the prongs of a fork to distort skin on other parts of the body—in these cases, the prongs feel misaligned even though the fork has not bent. The Tongue Twister illusion results from turning the tongue upside down and probing it with a finger or foreign object—the object can be felt to be in the wrong spatial location, opposite to where it actually is on the tongue.