Central and Off-Axis Spatial Contrast Sensitivity Measured with Gabor Patches
Abstract
The U.S. Army acquisition community uses models of human and systems performance to evaluate materiel. One such model, used to assess equipment for the dismounted Soldier, is the Individual Warrior Simulation (IWARS). When Soldier modeling target acquisition, IWARS applies the ACQUIRE model to some portion of the visual scene, determines the probability of detecting a target if one is present, then repeats the process for a different portion of the field. ACQUIRE predicts the probability of visually acquiring a target presented anywhere within its field of view (FOV) without regard for the location of the target in the scene. Human visual performance varies dramatically across the FOV, with acuity decreasing rapidly as objects move away from the center of gaze or away from the central vertical and horizontal axes of vision. The current research used Gabor patches to characterize visual detection thresholds at various locations around central vision. Results showed a marked increase in contrast threshold for targets of a y of spatial frequencies ranging from 0.5 to 18.2 cycles/degree appearing greater than plus or minus 3 degrees minus 4 degrees horizontal eccentricity. These results can be used to intelligently constrain the portion of the visual field over which IWARS applies the ACQUIRE detection model.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2010
- Accession Number
- ADA532054
Entities
People
- Joel T. Kalb
- Kent E. Higgins
- William A. Monaco
Organizations
- United States Army Research Laboratory