Center-surround cells. Drag the receptive field around the image to see how it responds to parts of a scene. The on-field is yellow and the off-field is blue. The number (0 to 100) represents the total response. How can center-surround fields explain Mach bands and the Hering grid? How do different sizes of field affect the response? Select a scene from the dropdown menu or test your own. (Drag an image file or paste an image into this window.)
Of course, receptive fields in your retina do not move, but your eyes move to scan an image and your retina contains many center-surround fields of different sizes.