The Ring Rotation Illusion: Properties and Links of a Novel Illusion of Motion.

Uwe Mattler,Robert Fendrich,Maximilian Stein

doi:10.1177/20416695211020019

Uwe Mattler, Robert Fendrich + Show 1 more

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https://doi.org/10.1177/20416695211020019

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Abstract

We report a novel visual illusion we call the Ring Rotation Illusion (RRI). When a ring of stationary points replaces a circular outline, the ring of points appears to rotate to a halt, although no actual motion has been displayed. Three experiments evaluate the clarity of the illusory rotation. Clarity decreased as the diameter of the circle and ring increased and increased as the number of points forming the ring increased. The optimal interstimulus interval (ISI) between the circle and ring was 90 ms when stimulus presentations lasted 100 ms but 0 ms with 500 ms presentations. We compare the RRI to the Motion Bridging Effect (MBE), a similar illusion in which a stationary ring of points replaces an initial ring of points that spins so rapidly it looks like a stationary outline. A rotation of the stationary ring is seen that usually matches the direction of the initial ring’s invisible spin. Participants reported a slightly more frequent and clearer motion percept with the MBE than RRI. ISI manipulations had similar effects on the two illusions, but the effects of number of points and ring diameter were largely restricted to the RRI. We suggest that both the RRI and MBE motion percepts are produced by a visual heuristic that holds that the transition from an outline circle to a ring of points is plausibly explained by a rapid spin decelerating to a halt, but in the case of the MBE, an additional direction-sensitive mechanism contributes to this percept.

Highlights

We report a novel visual illusion we call the Ring Rotation Illusion (RRI)
We introduced the “Ring Rotation Illusion,” which is defined as the illusory rotation of a stationary ring of points when it replaces a stationary outline circle
We report evidence for a new illusion, the “Ring Rotation Illusion,” which occurs when a circular outline is followed by a stationary ring of points

Summary

Introduction

We report a novel visual illusion we call the Ring Rotation Illusion (RRI). When a ring of stationary points replaces a circular outline, the ring of points appears to rotate to a halt, no actual motion has been displayed. ISI manipulations had similar effects on the two illusions, but the effects of number of points and ring diameter were largely restricted to the RRI We suggest that both the RRI and MBE motion percepts are produced by a visual heuristic that holds that the transition from an outline circle to a ring of points is plausibly explained by a rapid spin decelerating to a halt, but in the case of the MBE, an additional direction-sensitive mechanism contributes to this percept. A continued investigation of the MBE’s functional dependencies (Stein et al, 2019) raised the possibility that the motion percept and motion direction information were dissociable signals This led to the speculation that while the direction information must be derived from the inducing ring spin, the actual motion percept might represent an instance of apparent motion produced by the transition from an apparently continuous to a point defined ring outline

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