In a noisy restaurant, music plays, glasses clink, and servers discuss the specials. All of these sounds hit the eardrum at the same time, yet conversation continues easily because of a process that allows humans to isolate, identify, and prioritize overlapping sounds.
Visual illusions, such as the rabbit-duck (above), are fascinating because they remind us of the discrepancy between perception and reality. But our knowledge of such illusions has been largely limited to studying humans.