"Shape from shadows": Correction to Cavanagh and Leclerc (1989).

Reports an error in the original article by P. Cavanagh and Y. G. Leclerc (Journal of Experimental Psychology: Human Perception and Performance, 1989, Vol 15[1], 3–27). Corrections are made to the brightness levels of panels g, h, and i of Figure 4. (The following abstract of this article originally appeared in record 1989-17755-001.) The colors, textures, and shapes of shadows are physically constrained in several ways in natural scenes. The visual system appears to ignore these constraints, however, and to accept many patterns as shadows even though they could not occur naturally. In the stimuli that we have studied, the only requirements for the perception of depth due to shadows were that shadow regions be darker than the surrounding, nonshadow regions and that there be consistent contrast polarity along the shadow border. Three-dimensional shape due to shadows was perceived when shadow areas were filled with colors or textures that could not occur in natural scenes, when shadow and nonshadow regions had textures that moved in different directions, or when they were presented on different depth planes. The results suggest that the interpretation of shadows begins with the identification… (PsycINFO Database Record (c) 2010 APA, all rights reserved)