Geometrical Figures | Illusions by Roger Shepard | Stroop Effect
This illusion is called the Necker Cube.
Keep your eyes on the blue dot. Is it in front, or in back of the cube?
The stairs should turn upside down during a steady gaze.
Where does this triangle end, where does it start?
Source of the following four figures: Roger Shepard (1990). Mind Sights: Original Visual Illusions, Ambiguities, and Other Anomalies. San Francisco: W. H. Freeman.
At the top of the picture you see happy faces, at the bottom the faces are sad. If you turn the picture around you'll get the same effect.
Do you trust your counting abilities? How many feet does this elephant have?
Anything strange about this wheel?
What's wrong with this arch?
Try calling out loud the color of each word as fast as you can!
This optical illusion is called the 'Stroop Effect'.
