Apparent color-orientation bindings in the periphery can be influenced by feature binding in central vision.

A previous study reported the misbinding illusion in which visual features belonging to overlapping sets of items were erroneously integrated (Wu, Kanai, & Shimojo, 2004, Nature, 429, 262). In this illusion, central and peripheral portions of a transparent motion field combined color and motion in opposite fashions. When observers saw such stimuli, their perceptual color-motion bindings in the periphery were re-arranged in such a way as to accord with the bindings in the central region, resulting in erroneous color-motion pairings (misbinding) in peripheral vision. Here we show that this misbinding illusion is also seen in the binding of color and orientation. When the central field of a stimulus array was composed of objects that had coherent (regular) color-orientation pairings, subjective color-orientation bindings in the peripheral stimuli were automatically altered to match the coherent pairings of the central stimuli. Interestingly, the illusion was induced only when all items in the central field combined color and orientation in an orthogonal fashion (e.g. all red bars were horizontal and all green bars were vertical). If this orthogonality was disrupted (e.g. all red and green bars were horizontal), the central field lost its power to induce the misbinding illusion in the peripheral stimuli. The original misbinding illusion study proposed that the illusion stemmed from a perceptual extrapolation that resolved peripheral ambiguity with clear central vision. However, our present results indicate that visual analyses of the correlational structure between two features (color and orientation) are critical for the illusion to occur, suggesting a rapid integration of multiple featural cues in the human visual system.