A new visual phenomenon that we call flashing anomalous color
contrast is described. This phenomenon arises from the interaction
between a gray central disk and a chromatic annulus surrounded by black
radial lines. In an array of such figures, the central gray disk no
longer appears gray, but assumes a color complementary to that of the
surrounding annulus. The induced color appears: (1) vivid and
saturated; (2) self-luminous, not a surface property; (3) flashing with
eye or stimulus movement; (4) floating out of its confines; and (5)
stronger in extrafoveal than in foveal vision. The strength of the
effect depends on the number, length, width, and luminance contrast of
the radial lines. The results suggest that the chromatic ring bounding
the inner tips of the black radial lines induces simultaneous color
contrast, whereas the radial lines elicit, in conjunction with the gray
disk and the ring, the flashing, vividness, and high saturation of the
effect. The stimulus properties inducing the illusion suggest that
flashing anomalous color contrast may be based on asynchronous
interactions among multiple visual pathways.
Flashing anomalous color contrast