Motion undershoot. Bar rotates through 180°, from 12 to 12 o’clock.  But it appears to move only from 1 to 11 o’clock.

[quicktime width=”600″ height=”400″]http://quote.ucsd.edu/anstislab/files/2012/11/movie-1.mov[/quicktime]height=”400″]http://quote.ucsd.edu/anstislab/files/2012/11/movie2.mov[/quicktime]


Same as the ring but for linear motion. Red and green bars are in the same position but appear to be offset. Try tracking them with your eyes; your eyes feel as if they move, but they really don’t!!

[quicktime width=”600″ height=”400″]http://quote.ucsd.edu/anstislab/files/2012/11/WonkyCross.mov[/quicktime]

Same idea here! Right-angled cross looks wonky because moving sector edges shift the cross arms more than moving middles of sectors.