Amazing Optical Illusion

Perceptual Constancies
Perceptual constancies are sources of many illusions. Color constancy and brightness constancy are responsible for the fact that a familiar object will appear the same color regardless of the amount of light reflecting from it. An illusion of color difference can be created, however, when the luminosity of the area surrounding an unfamiliar object is changed. The color of the object will appear darker against a black field which reflects less light compared to a white field even though the object itself did not change in color. Like color, the brain has the ability to understand familiar objects as having a consistent shape or size. For example a door is perceived as rectangle regardless as to how the image may change on the retina as the door is opened and closed. Unfamiliar objects, however, do not always follow the rules of shape constancy and may change when the perspective is changed. The Shepard illusion of the changing table is an example of an illusion based on distortions in shape constancy.

Sensation And Perception
Much of our knowledge begins as sensation. Information about physical changes is received by sensory neurons, transmitted to the brain, and interpreted or perceived. Each sensory system is structured to receive a particular form of physical energy and convert it into neural impulses to the brain.



The visual system processes light information, which is focused by the cornea and lens, received by light sensitive neurons in the retina called rods and cones, and transmitted to the brain via the optic nerve.




The process of audition or hearing involves translating sound -- a form of mechanical energy -- into neural energy. They qualities of sound amplitude and frequency are translated into the experiences of loudness and pitch. Both qualities are funneled via vibrations through the outer ear, along the structures of the middle ear, and to the vibration-sensitive hair cells in the inner ear. These specialized neurons transmit impulses along the auditory nerve to the brain.




Other senses studied included the vestibular sense or sense of balance; the skin senses, including touch and proprioception; gustation or taste; and olfaction or smell.