Synchronization, decrease in strength of pattern, illusory contours, and neon-color effect.

When certain elements in a pattern are replaced by colored lines, a spreading of neon-like color can be seen around the lines. Using a variety of neon displaying patterns, we hypothesize that two conditions are critical to the neon effect. One is the occurrence of illusory contours and another a decrease in strength of pattern of the colored lines. On the basis of the two conditions, various phenomena of the neon effect are discussed. Finally, examining the striking characteristics of the neon effect, the vagueness of the colored lines and the spreading of the color of the colored lines over an illusory area wherein the color stimulus does not exist, we conclude that the neon effect is caused by synchronization of strength of pattern.