Increase and decrease of optical illusion strength by vibration

Abstract

Optical illusions, such as the optimized FraserWilcox figures, are perceived to be moving although they are perfectly still. Optical illusion intensity substantially increases in a color-dependent FraserWilcox figure vibrated at several Hz. By contrast, the intensity decreases in other types of optical illusion subjected to vibration. It is difficult to control the frequency and amplitude of vibration made by hand precisely. Vibrating a figure on the PC display by software may be affected by the response time and limited refresh rate of the PC display. Therefore, we developed a vibration equipment by using a positive mechanical constraint cam. Various optical illusion figures were vibrated using the equipment to determine the relationship of optical illusion strength to the amplitude and frequency of vibration. Results showed that the proposed equipment can effectively determine the vibration frequency and stroke in which optical illusions can be recognized.