Two Processes in Feature Misbinding: (1) Enabling Misbinding and (2) Contributing Features

Abstract

Peripheral visual objects may be mistakenly perceived to have the features of objects in the central visual field (illusory conjunctions). An ambiguity-resolving mechanism is posited to use information from the center to resolve peripheral ambiguity (Wu, Kanai & Shimojo, Nature 2004). RATIONALE: (a) If objects with no motion do not cause motion ambiguity and ambiguity is necessary for misbinding, then misbinding of motion should not occur for objects without motion. (b) If the central stimulus initiates resolution of motion ambiguity, then misbinding should not occur when the center is blank. (c) If the center contributes essential information to resolve ambiguity, then the misbound feature values within the periphery should be in the central stimulus. METHODS: The stimulus had random dots, each one red or green. The central stimulus was either (1) blank or (2) had red dots moving upward and green dots moving downward. The peripheral stimulus always had red and green dots: peripheral red dots either (1) had no motion (constant locations presented either steadily or pulsed on and off), or (2) had ambiguous motion (a new random location, independently for each dot in each frame, or a new random direction of movement, independently for each dot in each frame). Peripheral green dots moved (1) upward (same direction as central red dots) or (2) downward (opposite from central red dots). Observers reported the directions of motion of the majority of peripheral (1) red dots and (2) green dots. RESULTS: No misbinding of motion was found when peripheral red dots did not move or when the center was blank. When central red dots and peripheral green dots moved in opposite directions, the misbound motion of randomly moving peripheral red dots could be in either direction. CONCLUSION: The center initiates misbinding but is not the sole source for misbound feature values.