Project Details

The running applet must follow these steps:

• Flash a red square for 150 milliseconds.
• Pause 50 milliseconds.
• Flash a green square for 150 milliseconds.
• Pause 1500 milliseconds.
• Repeat

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When the images are separated by the appropriate angle of vision , phi, the effect is a visual illusion of apparent motion. The red square appears to smoothly slide across the field towards the green square. A curious observation is that although movement appears continuous, the color switches abruptly at the midpoint. When the initial shape is different from the final, the shape appears to morph into the second with color filling in or receding but still changing abruptly in the center.

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Parameters desirable to be controlled by the user:
(arranged in order of importance)

1. Visual angle of separation (3.6 degrees)
2. Size of objects (0.9 degrees)
3. Speed of flashes (as above)
4. Color of objects (red, green, blue, yellow)
5. Shapes of objects (squares)
6. Color of background field (white)
7. Addition of other lines and objects to divert apparent path

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Those who can view applets:The Applet

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Experiment details and parameters above shown as default from:

Kolers and Grunau, "Shape and Color in Apparent Motion" in Vision Research, Vol. 16, 1976, pp. 329-335.

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