Perception of Motion Orientation Using Divergence, Size Change and Velocity Change.
Abstract
As an observer moves relative to a textured surface such as the ground, there is motion-related visual information available from that surface through three specific geometrical variables. These are vergence, size change and velocity change. As the textural elements move closer to the observer their paths of motion on the retina diverge. Movement away leads to convergence. Size of the elements also changes as function of distance as does velocity. The purpose of this experiment was to determine the effectiveness of each variable and to assess their interactions in foveal and in peripheral viewing. The objective was to acquire information needed for movement display design as well as to discover more about the information humans use for orientation. In this experiment displays were viewed in which the three variables were electronically separated and variously presented singly, in all possible pairs, and altogether in one display. The oscilloscope display consisted of 64 downward moving elements designed to simulate a moving surface tilted 75 deg away from the observer. Subjects communicated their perceptions of degree of perceived surface tilt at the top, bottom and middle of the display for the eight different combinations of variables. They also responded to apparent velocities of these same display areas. The results showed that all three variables can lead to relatively reliable perceptions of motion in depth with velocity change being the most powerful determiner and with size change being the weakest. Subjects consistently underestimated the amount of simulated tilt.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1978
- Accession Number
- ADA060032
Entities
People
- Marcia K. Harrington
- Thomas L. Harrington
Organizations
- University of Nevada, Reno