Some Further Visual Phenomena associated with Regular Patterned Stimulation

Abstract

IN a recent article¹ I described some striking effects of visual stimulation by regular patterns. The principal feature of these is the appearance of what may be called a ‘complementary pattern’ the main outlines of which run roughly at right-angles to those of the stimulus-pattern. A ‘ray’ pattern of radial lines, for example, produces an after-impression of wavy lines moving in concentric circles; a pattern of concentric circles produces an after-image of wavy radial streamers. These complementary patterns may also be evoked continuously in stroboscopic light, or in a background of visual ‘noise’ (on a television screen) viewed through a transparency of the stimulus pattern.