Pressnitzer D, Hupé JM (2006) Temporal dynamics of auditory and visual bistability reveal common principles of perceptual organization. Current Biology. 16, 1351-1357. [journal][preprint][supplemental data]
Visual plaids perception. When fixating the red dot for a prolonged period of time, perception should alternate between a single plaid moving upwards (Grouped percept) or two gratings sliding laterally on top of each other (Split percept). The first percept is usually Grouped.
Interactive version. To help seeing the Split percept, you may try increasing the speed. To help seeing the Grouped percept, you may try decreasing the angle between components. You will need a shockwave player in case you do not already have one installed.
Stand-alone version. For Windows only.
Movie version. Save this quicktime movie to disk and make sure to play it in 'Loop' mode.
Sound 1. Perception of a single auditory stream. In this example, two pure tones alternate in an ABA- pattern with a small frequency difference, 2 semitones. The perception is that of one single stream with a galloping rhythm (Grouped).
Sound 2. Perception of a two auditory streams. The frequency difference between the A and B tones is now large, 11 semitones. The perception is that of two separate, isosynchronous streams (Split).
Sound 3. Bistable auditory streaming. The frequency difference between the A and B tones is now intermediate, 5 semitones. Upon listening to the sound for a prolonged period of time, perception should alternate between one and two streams (Grouped and Split).