Contrast response of human visual mechanisms sensitive to orientation and direction of motion

Abstract

A slowly moving grating of low spatial frequency differentially raises the threshold of various kinds of test targets. Systematic variation of the contrast of the adaptation grating separates two distinct components of this response. One component depends upon the grating's orientation and is a power function of contrast. This component is independent of the grating's movement. The other component is controlled by the direction of movement of the grating and is sensitive only to a restricted range of low contrasts. © 1969.