Neuroscience Animations

John H. Krantz, Hanover College, krantzj@hanover.edu

Lateral Inhibition Effects

Brief description and instructions (DRAFT):

Lateral inhibition has been used to explain several visual illusions such as Mach Bands and Simultaneous Contrast. This applet illustrates the nature of how these center-surround receptive fields explains these illusions.

The top left part of the screen shows an areas of the retina. The circles are different ganglion cell receptive fields, each overlapping its neighbor. The color of the receptive field indicates how strongly its ganglion cells is firing. Blue is the background level, it turns more greed the faster it is firing and more black the less it is firing. Below is a bar graph where each bar represents one cell from the top area of the screen. The bars are in the same order as the cell. The horizontal line shows the background firing rate that the cell has when it is not being stimulated.

On the right side of the screen is a menu of different stimuli that you can use to stimulate the ganglion cells. You can choose Mach Bands, a white sheet of paper, Craik-O'Brien-Cornsweet Illusion, Minimal Contours, and Simultaneous contours. Below this menu is another menu where you can choose whether the ganglion cells on on-center or off-center. When the Craik-O'Brien-Cornsweet and Minimal contours are selected, you can select to show the light level pattern of the light over the receptive fields by (Show Profile) below the Other Controls label. When you select Simultaneous Contrast, in Increase and Decrease button will appear below Other Controls which will allow you to increase or decrease the light level of the surround (outside areas).

Click here to open the applet. It will open a new window that will fill your screen.

Reference:

Kuffler, S. W. (1953). Discharge patterns and functional organization of mammalian retina. Journal of Neurophysiology, 16, 37-68.