Related Experiment Video
Updated: Aug 11, 2026

Testing Visual Sensitivity to the Speed and Direction of Motion in Lizards
Published on: December 14, 2006
An illusion of 3-D motion with the Ternus display
Michael D Dodd1, Tara McAuley, Jay Pratt
1Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ont., Canada M5S 3G3. michaeld@psych.utoronto.ca
Abstract:
We attempted to eliminate the percept of element motion in the Ternus display by connecting the display elements so that they appeared to be a single object. On each trial, the display elements (two discs) appeared either separated or connected (either via a white line or side by side) and subjects reported whether they observed element motion or group motion at various ISIs. Although it was hypothesized that element motion would be eliminated in the connected condition, subjects observed element motion at short ISIs in the form of a three dimensional illusion in which one element appeared to rotate out in front of (or behind) the other. Implications for short range and long range motion processes are discussed.
More Related Videos
Related Concept Videos
Velocity and Position by Graphical Method
Uniform Circular Motion
Non-uniform Circular Motion
For example, such accelerations...
Upward Impending Motion
To better comprehend how a screw jack functions, consider the completely unraveled thread as a block in contact with the...
Curvilinear Motion: Normal and Tangential Components
The positive direction of the t-axis aligns with the increasing position of the car along the curved path, denoted by the unit vector ut. Simultaneously, the n-axis, perpendicular to the t-axis, dissects the curved path into differential arc segments, each forming the arc of a circle with a radius of...
Cylinders in Three-Dimensional Space

