2021 Third prize
Dawei Bai & Brent Strickland – “The Double Ring Illusion”
Institution: Département d’Études Cognitives, École Normale Supérieure, PSL Research University, Institut Jean Nicod Paris, France and Africa Business School; School of Collective Intelligence , Morocco
Authors description: When two bistable rings are presented separately, they appear to move in unstable 360° rotations. However, if the same rings partially overlap, they now appear to move in stable 180° rotations, bouncing back and forth – as if they avoid passing through each other. Remarkably, when one ring is holed, in a way that the other ring can pass through the holes, the unstable 360° percept is restored. In all three cases, the rings undergo the exact same motion, but our visual system interprets the stimuli differently depending on whether the rings can traverse each other.