Color from Motion
(or Subjective Color from Apparent Motion)

Background:

Cicerone, Hoffman, Gowdy and Kim (1995) showed participants a set of red dots that were randomly placed on a white background. The position of the dots never change, but the color of the dots were systematically changed such that all the dots within a circular region changed to green. The circular region moved across the field of red dots. If you want to see something similar to Cicerone et al.'s stimuli, scroll down and click the Start button.

You might have perceived a couple of things when you looked at the activity below. First, a circular area appears to move across the field of red dots. That motion is illusory -- none of the dots move, only the color of the dots change. Second, the area around the green dots appears to take on a greenish hue. That color is illusory also -- the background remains white. The perceived color is what Cicerone et al. (1995) called "dynamic color spreading." More recent work from Cicerone's lab tends to use the term CFM -- color from motion.

The color from motion phenomenon should remind you of other phenomena that you may have seen in your study of perception. The fact that a circle is often perceived when there is no physical boundary present suggests an illusory contour. The fact that the color spreads from the green dots into the surround areas suggest neon color spreading. Chen and Cicerone (2002) argue that the color from motion phenomenon is independent of both illusory contours and neon color spreading. They tested color from motion with a background and dot colors that were isoluminant (that is, the background and dots were the same brightness, but different colors), the color from motion illusion occurred. However, the subjective contour does not occur. Neon color spreading can occur in a stationary image, but color from motion is greatly attenuated in a stationary image (Chen and Cicerone show that it still occurs, but at so low a level that people do not subjectively report it).

The Activity:

This activity allows you to explore the color from motion phenomenon by adjusting the colors of the background, the initial color of the dots, and the color that the dots change to. You can also see whether motion is necessary or not by stopping the circular area of change.

Can you find a combination of the three colors where the color from motion illusion is extinguished or enhanced? Can you form a hypothesis about relationship between the three colors and the illusion?

When forming your hypotheses, remember to think about color psychologically -- think of it in terms of hue (H), saturation (S) and brightness (V).

References

Chen, V. J. & Cicerone, C. M. (2002). Subjective color from apparent motion. Journal of Vision, 2, 424-437. http://dx.doi.org/10.1167/2.6.1

Cicerone, C. M., Hoffman, D. D., Gowdy, P.D., & Kim, J. S. (1995). The perception of color from motion. Perception & Psychophysics, 57 , 761-777. http://dx.doi.org/10.3758/bf03206792