Explain the center-surround receptive field organization of retinal ganglion cells and its contribution to contrast.

Explain the center-surround receptive field organization of retinal ganglion cells and its contribution to contrast.

• A. Retinal ganglion cells have center-surround receptive fields that enhance edge detection via lateral inhibition.
• B. Center-surround organization is present only in ON-center cells.
• C. The center is always excited by light and the surround is always inhibited.
• D. The center and surround operate independently with no influence on edges.

Answer: (A)

Center-surround receptive fields act as a spatial filter that emphasizes changes in light rather than uniform brightness, boosting contrast at edges. The center and the surrounding ring have opposite influences: in ON-center cells, light in the center increases firing while light in the surround suppresses it via lateral inhibition from horizontal cells; in OFF-center cells, the pattern is reversed. When illumination is uniform across the entire receptive field, the center and surround inputs largely cancel, yielding little response. At an edge, the center and surround experience different light levels, producing a larger net change in output and making edges stand out. This antagonistic arrangement exists in both ON- and OFF-center ganglion cells, and it’s the interaction between center and surround that underpins edge detection and contrast sensitivity.

Center-surround receptive fields act as a spatial filter that emphasizes changes in light rather than uniform brightness, boosting contrast at edges. The center and the surrounding ring have opposite influences: in ON-center cells, light in the center increases firing while light in the surround suppresses it via lateral inhibition from horizontal cells; in OFF-center cells, the pattern is reversed. When illumination is uniform across the entire receptive field, the center and surround inputs largely cancel, yielding little response. At an edge, the center and surround experience different light levels, producing a larger net change in output and making edges stand out. This antagonistic arrangement exists in both ON- and OFF-center ganglion cells, and it’s the interaction between center and surround that underpins edge detection and contrast sensitivity.