Pattern ERG uses which type of stimulus to evoke retinal responses?

• A. Random noise pattern
• B. Checkerboard or grating display
• C. Uniform color patch
• D. Moving stripes

Answer: (B)

Pattern ERG relies on a high-contrast, reversing pattern to evoke retinal responses. The typical stimulus is a checkerboard or grating display that alternates its pattern (edges and contrasts) over time. This kind of pattern specifically engages how the retina resolves fine spatial detail and edge information, which drives the ganglion cell pathways in the central retina. Because the response depends on tracing changes in spatial structure rather than simply a change in overall brightness, the checkerboard or grating pattern provides a clear, repeatable signal that isolates inner retinal function.

In contrast, a random noise pattern doesn’t provide a consistent, interpretable pattern of edges for the retina to lock onto, a uniform color patch has no spatial structure to drive pattern processing, and moving stripes emphasize motion processing rather than the static pattern sensitivity that PERG targets. So the checkerboard or grating display is the stimulus that best evokes pattern-related retinal responses.