Orientation contrast vs orientation in line-target detection

Orientation contrast vs orientation in line-target detection

This study concerns the roles of absolute and relative orientation in determining detectability of a line-element target in a background field of uniformly oriented line elements. Target detectability was determined as a function of background-field orientation, sampled at 5 deg intervals, for three levels of orientation contrast--the difference between target and background orientations--sampl...

Orientation Only Orientation and Contrast Transition Orientation and Optic Flow Orientation and Colour

Orientation integration in detection and discrimination of contrast-modulated patterns

Orientation detection and discrimination thresholds were measured for Gabor 'envelopes' formed from contrast-modulation of luminance 'carriers'. Consistent with previous research differences between carrier and envelope orientation had no effect on sensitivity to envelopes. Using plaid carriers in which the proportion of contrast modulation 'carried' by each plaid component was systematically m...

Contrast Detection and Orientation Discrimination Thresholds Associated with Meridional Amblyopia

Humans who have astigmatism resulting in meridional amblyopia exhibit deficits in performing visual tasks at or near detection thresholds. However, there is mounting evidence supporting the idea that performance at threshold may not reliably predict visual capabilities at supra-threshold levels of stimulation. In this study the threshold and supra-threshold performance of six meridional amblyop...

Facilitation of contrast detection by flankers without perceived orientation.

To extract meaningful structure from noisy input signals, the human visual-processing system uses elementary structures, such as contours, to extract more complex informative structures. The first step in contour processing involves identifying local orientation. The phenomenon of collinear facilitation is important for understanding how orientation detection is implemented; at the fovea, a str...