DETECTING AND DISCRIMINATING CURVED GABORS FOR STATIC, DRIFTING, AND WARPING STIMULI

摘要

The capacity to detect and discriminate curvature for static, drifting, and warping stimuli was assessed by measuring contrast sensitivity to Gabor stimuli with different curvature levels and for two different eccentricities (0 and 20 degrees). In general, the data show that, for central vision, there was no difference in curvature thresholds between the static and dynamic conditions. However, at 20 degrees, the subjects were more sensitive to the dynamic stimuli at all curvature levels and warping stimuli for large curvatures. Discrimination thresholds were similar to detection thresholds when discrimination was between horizontal vs. vertical gratings or when the task was to discriminate between large curvatures. However, decreasing the curvature by log steps increased the discrimination thresholds while the detection threshold curve remained flat for all stimuli.