Stepping Feet Illusion

Observe the two moving rectangles. They appear to take alternating "steps". However, they are actually moving at a constant, identical speed. Use the controls to reveal the illusion.

Stepping Feet Demo

Choose the viewing condition, then hand the phone to the participant.

Viewing condition

Watch the motion

After watching, answer three quick questions:

  • What did you see most?
  • Where was your attention?
  • How strong was the effect?
Watch the motion

Viewing condition

What did you notice?

What did you see most?
Where was your attention?
How strong was it?