Local and Global Motion with Juno Kim

[quicktime width=”500″ height=”400″]http://anstislab.ucsd.edu/files/2012/11/Glob.RedBalls-4.mov[/quicktime]

At first, this ambiguous motion stimulus looks like four pairs of dots, each rotating about their common center, but after a while it perceptually reorganizes into two large squares (with a dot at each corner) floating over each other. These local and global forms of “common fate” often alternate; on a 30s trial, local motion is usually seen first, followed by global motion. And across a series of trials, global motion is gradually seen more often. This suggests two adaptation (or learning) processes with different time constants.

[quicktime width=”500″ height=”400″]http://anstislab.ucsd.edu/files/2012/11/Glob.Cubes-2.mov[/quicktime]

We usually see these upright cubes as two large globally moving squares, not as local pairs of cubes.

[quicktime width=”500″ height=”400″]http://anstislab.ucsd.edu/files/2012/11/Glob.Faces-2.mov[/quicktime]

Conversely, the lovers gazing into each other’s eyes are seen not as a large female square and large male square but as locally moving pairs.

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

Each pair of spots is phase shifted by 45 degrees from its neighbors. The blue circles tend to constrain the pairs to remain local.

[quicktime width=”600″ height=”400″]http://anstislab.ucsd.edu/files/2012/11/NautiNew13.mov[/quicktime]

Without the circles, one perceives two intertwined global octagons.