Visual and Auditory Sensitivities and Discriminations
Abstract
Errors in judging absolute time to collision using monocular information alone range from 2 to 12% and from 2.5 to 10% using binocular information alone, but only 1.3 to 2.7% using the combination. For small targets, judgements are based entirely on binocular information. Individuals make large errors in judging absolute time to collision with a rotating nonspherical object when judgements are based on monocular information, but not when binocular information is provided. When simulating closure with a textured object, systematic errors in judging time to collision can occur if the rates of expansion of texture element size and object size are not matched exactly. Exposure to expanding images produces errors in judging time to collision that may cause errors in NOE flight and may be a cause of rear-end highway collisions. The human visual system does contain binocular mechanisms sensitive to speed. Simulated objects can be seen and recognized entirely on the basis of texture differences. The physiological limit for locating a texture-defined boundary is 1.7 to 2.4 min are, and visual acuity for texture-defined gratings is above 7 c/deg. Spatial frequency discrimination threshold is approx. 5% for both texture-defined and luminance-defined gratings for frequencies less that 3 - 4 c/deg.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2000
- Accession Number
- ADA376091
Entities
People
- David Regan
Organizations
- University of York