FLOATINGFINGER ILLUSION

   A term introduced in or shortly before 1928 by the American psychologist Winford Lee Sharp (1890-1975) to denote a *visual illusion that can be induced by placing the index fingers of each hand horizontally in front of the eyes, at a distance of about 30 cm, with the fingertips touching, and one's gaze focused on a point in the distance. When the fingertips are then drawn apart, a seemingly disembodied finger can be perceived, with two ends, apparently floating in mid-air. The floating-finger illusion is generally regarded as a * binocular illusion. It can also be classified as a *phantom sensation or a *body schema illusion.

   References

   Sharp, W.L. (1928). The floating-finger illusion. Psychological Review, 35, 171-173.