Retinal mechanisms in the perception of subjective contours: the contribution of lateral inhibition.

One mechanism frequently proposed for the creation of subjective contours and their related brightness effects involves lateral neural interactions on the retina, such as the lateral inhibitory effects that underlie brightness contrast. Subjective contour stimuli were displayed under an intermittent light source, with rapid onset and slow offset as has been shown to increase lateral inhibitory interactions by allowing summation of neural onset transients. A sample of forty subjects, using magnitude estimates, reported increased subjective contour clarity and brightness effects under these exposure conditions. The effects were larger for relative brightness differences than for contour visibility. It appears that this technique may have applications in exploring retinal contributions to other aspects of the perception of subjective contours.