Spatiotemporal Characteristics of Visual Localization. Phase 2
Abstract
Experimental psychophysical research was performed on the basic problem of how human observers determine tha size and relative positions of objects in a visual scene. The first problem addressed was: Can these abilities be accounted for by the stages of visual processing that have already been postulated to account for contrast detection results, specifically, by local spatial filters with various peak spatial frequencies? What are the properties of the mechanisms that are responsible for these abilities and what is their relationship to the local spatial filters? Research reveals that the size and separation judgements are made by a mechanism with rapid temporal response that is largely largely insensitive to the spatial characteristics of the objects themselves. The mechanism can also select the best source of information, using small, high-spatial-frequency filters when the targets are crowded and using large, low-spatial-frequency filters, with their higher signal/noise ratios, under uncrowded conditions. This mechanism is also largely insensitive to the eccentricity of the targets, although at sufficiently large separations at large eccentricities, a qualitatively different mechanism appears to come into play.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1988
- Accession Number
- ADA204806
Entities
People
- Christina A. Burbeck
Organizations
- SRI International