Kinetic art expressions based on optical and luminous phenomenon as well as painting illusionism. The expression "kinetic art" in this modern form first appeared at the Museum für Gestaltung of Zürich in 1960, and found its major developments in the 1960s. In most European countries, it generally included the form of optical art that mainly makes use of optical illusions, such as op art, represented by Bridget Riley, as well as art based on movement represented by Yacov Agam, Carlos Cruz-Diez, Jesús Rafael Soto, Gregorio Vardanega, or Nicolas Schöffer. From 1961 to 1968, GRAV ("Groupe de Recherche d’Art Visuel") founded by François
Ponzo illusion not subject to the size illusion. In other words, the opening between the index finger and thumb is scaled to the real not the apparent size of the target object as the grasping hand approaches the object. Cross-cultural differences in susceptibility to the Ponzo illusion have been noted, with non-Western and rural people showing less susceptibility. Other recent research suggests that an individual's receptivity to this illusion, as well as the Ebbinghaus illusion, may be inversely correlated with the size of that individual's primary visual cortex. Ponzo illusion The Ponzo illusion is a geometrical-optical illusion that was first demonstrated by