Integration regions for visual hyperacuity

Abstract The robustness of vernier acuity to retinal image motion is not due to target feature detection while the pattern is swept past one or more “templates” that match the target offset. Stimuli which by themselves are subthreshold. devoid of contours or even of contrary information content, can be pooled and used for a visual hyperacuity response, i.e. differential spatial localization precise to a few seconds of arc in the human fovea. These integration processes take place in regions extending over several min arc in the direction along which differential localization takes place, and not only, as suggested by Hering, along the length of vernier lines.