2. Vision and Visual Illusions

We have discovered and helped characterized several optical illusions, including illusory rebound motion, illusory color mixing, gradient-offset induced motion, infinite regress illusion, dancing bar illusion, and corner angle illusion. These optical illusions are mistakes made by the visual system that may reveal the normal functioning of human mind.

Kohler, P.J., Caplovitz, G.P., Hsieh, P.-J., Sun, J., and Tse, P.U. (2010). Motion fading is driven by perceived, not actual angular velocity. Vision Research. 49, 439-50. (PDF)

Hsieh, P.-J., and Tse, P.U. (2009). Feature mixing rather than feature replacement during perceptual filling-in. Vision Research. 49, 439-50. (PDF)

Hsieh, P.-J., and Tse, P.U. (2009). Motion fading and the motion aftereffect share a common process of neural adaptation. Attention, Perception and Psychophysics. 71, 724-33. (PDF)

Caplovitz, G. P., Barroso, D. J., Hsieh, P.-J., and Tse, P. U. (2008). fMRI reveals that neuronal feedback to ventral retinotopic cortex underlies perceptual grouping by temporal synchrony. Human Brain Mapping. 29, 651-61. (PDF).(Demo of stimuli. Download and play in loop mode.)

Tse, P.U., and Hsieh, P.-J. (2007). Component and intrinsic motion integrate in 'dancing bar' illusion. Biological Cybernetics. 96(1), 1-8. (PDF). (Demo of stimuli. Download and play in loop mode.)

Troncoso, X.G., Tse, P.U., Macknik, S.L., Caplovitz,, G.P., Hsieh, P.-J., Schlegel, A.A., Otero-Millan, J., and Martinez-Conde, S. (2007). BOLD activation varies parametrically with corner angle throughout human retinotopic cortex. Perception. 36, 808-20. (PDF).

Hsieh, P.-J., and Tse, P.U. (2007). Grouping inhibits motion fading by giving rise to virtual trackable features. Journal of Experimental Psychology: Human Perception and Performance. 33, 57-63. (PDF). (Demo of stimuli.)

Hsieh, P.-J., and Tse, P.U. (2006). Illusory color mixing upon perceptual fading and filling-in does not result in 'forbidden colors'. Vision Research. 46, 2251-58. (PDF).(Demo of stimuli.)

Hsieh, P.-J., and Tse, P.U. (2006). Stimulus factors affecting illusory rebound motion. Vision Research. 46, 1924-33. (PDF).

Hsieh, P.-J., Caplovitz, G.P., and Tse, P.U. (2006). Illusory motion induced by the offset of stationary luminance-defined gradients. Vision Research. 46, 970-78. (PDF). (Demo of stimuli.)

Tse, P.U., and Hsieh, P.-J. (2006). The infinite regress illusion reveals faulty integration of local and global motion. Vision Research. 46, 3881-85. (PDF).(Demo of stimuli.)

Caplovitz, G.P., Hsieh, P.-J., and Tse, P.U. (2006). Mechanisms underlying the perceived angular velocity of a rigidly rotating object. Vision Research. 46, 2877-93. (PDF).

Hsieh, P.-J., Caplovitz, G.P., and Tse, P.U. (2005). Illusory Rebound Motion and Motion Continuity Heuristic. Vision Research. 45, 2972-2985. (PDF).

Gradient-offset Induced Motion: Fixate on the dot, and you will see illusory motion after the offset of the stimulus.

Troxler fading (Perceotual Filling-in): fixate on the ceter dot, and the green disk will disappear from your consciousness.

Motion-induced blindness. Fixation on the center dot, and you will see the yellow dot in the upper-left corner disappears from you consciousness.

Illusory rebound motion. "Illusory rebound motion” (IRM) is qualitatively similar to illusory line motion (ILM). ILM occurs when a bar is presented shortly after an initial stimulus such that the bar appears to move continuously away from the initial stimulus. IRM occurs when a second bar of a different color is presented at the same location as the first bar within a certain delay after ILM, making this second bar appear to move in the opposite direction relative to the preceding direction of ILM. We suspect that IRM arises because of a heuristic about how objects move in the environment: In the absence of countervailing evidence, motion trajectories are assumed to continue away from the location where an object was last seen to move.