Abstract
Previous research on aging and the perception of 3-D shape has focused upon stereopsis and motion (e.g., Andersen & Atchley, 1995; Norman, Dawson, & Butler, 2000; Norman, Clayton, Shular, & Thompson, 2004). No research has yet investigated how older observers perceive the 3-D shape of surfaces defined by image shading or specular highlights. In this study, 10 younger ( .05), but there was a significant effect for judgments of slant (F=6.7, p < .001). The performance of both age groups was similarly improved by stereoscopic viewing (for tilt: F=16.7, p < .001; for slant: F=11.4, p < .01). The results indicate that older observers can effectively perceive local 3-D surface orientation from optical patterns of shading, texture, and/or specular highlights.