Sunny M Lee¹, Steven K Shevell¹; ¹University of Chicago

The effortless perception of a flying red frisbee belies an active feature binding process of the visual system that integrates separate features, such as color and motion. In the periphery, sparser neural representations can cause the veridical feature pairing of color and motion to be overwritten by that in the center. Currently, the limits of the stimulus differences that still result in induced feature misbinding are unknown. Aim: We investigated how 2D and 3D motion interact across the central and peripheral visual field by measuring induced color/motion feature misbinding. Method: Participants reported the perceived motion direction of dots of one color (red or green) in the periphery, while fixating centrally and viewing two sets of colored dots (one set red, one set green) moving in opposite directions. Misbinding was induced by reversing the motion directions assigned to the two colors of dots between the center and the periphery. Dots moved radially from center to periphery, either contracting or expanding to give the percept of 3D radial optic flow motion or 2D “flat” radial motion. A control condition presented vertically moving dots at different speeds in center and periphery. Results: Significant color/motion feature misbinding in the periphery was found when the stimuli were entirely a single motion type, either 2D “flat” motion or 3D optic flow motion. Overlaying 2D and 3D radial motions, however, reduced misbinding by over 50% compared to both sets of colored dots moving as a single motion type. Significant misbinding observed with vertically moving 2D dots of different speeds demonstrated that the different dot speeds in 2D versus 3D motion cannot explain these misbinding results. Conclusion: Reductions in peripheral feature misbinding with different motion types, but not speeds, is consistent with different visual-processing levels for color-motion feature binding for objects perceived in 2D and 3D motion.

Acknowledgements: Supported by NIH EY-026618