Localizing contours defined by more than one attribute.

Two experiments were run in order to test how information from different attributes is combined to localize contours. In Expt 1 the apparent position of a contour defined by one attribute was measured while a contour defined by another attribute was presented beside it. Interactions were found between all pairings of luminance, color, motion and texture. These results suggested that the information associated with each contour is integrated at a common site. In Expt 2 the precision of localization was measured for contours defined by one, two or three attributes (combinations of luminance, color and texture). The improvement in precision with additional attributes again supported an integration of contour information at a common site prior to a decision of localization.