Stepping feet illusion

figure1 and figure2

The stepping feet illusion is a motion perception phenomenon involving two "buses," one blue and one yellow, moving horizontally across a "street" consisting of black and white stripes. Although both of the buses move at a constant speed, their perceived speed varies dramatically.[1][2][3]

When the blue bus lies on the white stripes, the contrast is high (dark blue vs. white) and easily visible, so it appears to move faster than its actual speed.[1][2][3] On the contrary, when the blue bus is against the black stripes, the contrast is low (dark blue vs. black) and harder to see, so the movement looks slower (see figs. 1 and 2).[1][2][3] The opposite effects occur for the yellow bus.[4][5] The two buses resemble a pair of moving of feet, giving the illusion its name.[6]

Overall, the higher-contrast movements look faster than those with lower contrast.[1][4][5] The effect disappears when the street's striped texture is removed because there is no contrast remaining,[6] showing how an object's background can have a significant effect on its perceived speed.[7]

  • Stepping Feet Illusion[8]
    Stepping Feet Illusion[8]
  1. ^ a b c d Bertamini, M (2018). Programming Visual Illusions for Everyone. Cham: Springer International Publishing.
  2. ^ a b c Anstis, S (2003). "Moving Objects Appear to Slow Down at Low Contrasts". Neural Networks. 16 (5): 933–938. doi:10.1016/S0893-6080(03)00111-4.
  3. ^ a b c Anstis, S (2004). "Factors Affecting Footsteps: Contrast Can Change the Apparent Speed, Amplitude and Direction of Motion". Vision Research. 44 (18): 2171–2178. doi:10.1016/j.visres.2004.03.015.
  4. ^ a b Debczak, M (2015). "Look Closely at This Footstep Illusion".
  5. ^ a b Kitaoka, A; Anstis, S (2015). "Second-order Footsteps Illusions". I-Perception. 6 (6). doi:10.1177/2041669515622085. PMC 4975121.
  6. ^ a b Mathot, S (2012). "Stepping Feet and Tipsy Toddlers".
  7. ^ Howe, P.D.L; Thompson, P.G; Anstis, S.M; Sagreiya, H; Livingstone, M.S (2006). "Explaining the Footsteps, Belly Dancer, Wenceslas, and Kickback Illusions". Journal of Vision. 6 (12): 1396. doi:10.1167/6.12.5. PMC 2637218.
  8. ^ Bach, M. (2004). "Stepping Feet" Motion Illusion. Retrieved from http://www.michaelbach.de/ot/mot-feetLin/index.html