Murray RF, Morgenstern Y
Paper at BBCS 2008
How does the human visual system's assumption that light comes from above interact with visual cues indicating that light does not come from above in a particular scene? Following Sun and Perona (1998), we used visual search for a bump among dents to infer observers' implicit beliefs about direction of illumination. Our search stimuli were embedded in realistically rendered 3D scenes, with different simulated lighting directions in different conditions. Regardless of lighting direction, search performance indicated that observers always assumed that illumination came from above. That is, the light-from-above prior completely overrode contextual information about direction of illumination.