Stimulus from Johansson (1973; see also Hochberg & Fallon 1976).

Demo 1A

Note: in all of the following demos, the middle dot's motion remains the same; only the motion of the top and bottom dots is changed.

Same as Demo 1, but only showing the middle dot.

Demo 1B - middle dot only

Increasing the horizontal amplitude of the top and bottom dots' oscillation (all other parameters the same as in Demo 1).

Demo 2

Adding horizontal offset to the top and bottom dots.

Demo 3

Random dot kinematogram using the same motion structure. Here the middle dot corresponds to the central motion (inside the aperture), and the bottom/top dots correspond to the surround motion.

Demo 4A: random dot motion

Same as Demo 4A, but without the surround (red) dots.

Demo 4B: random dot motion, center only

Same as Demo 4A, but without the center (green) dots.

Demo 4C: random dot motion, surround only