The effects of lighting direction and rotation on the perceived 3D shape of faces

• DOI: 10.1167/jov.23.9.5379
• Publication Date: 2023-08-29T18:35:37Z
• Authors: Jordi Asher; Abigail Webb; Paul Hibbard

The surface properties that constitute 3D facial structures are key for identity recognition. Johnston, Hill & Carman (1992, Perception 21(3)) showed inversion effects on recognition, where error rates identifying inverted compared to upright faces greater, less marked when illuminated from below. authors suggest illumination below disrupts shape information processing, while spatial configural such both manipulations do not have an additive effect recognition impairment. present study utilises a gauge figure task measure face representation across four conditions (face lit above vs below, and rotated normal face) in 10 participants. Participants adjusted the slant tilt of so it appeared flush against face, at locations regular triangular grid. These were then used create map perceived structure each observer condition, which ground truth face. There was significant difference conditions, but rotation. However, after conducting affine transformation data, there no remaining differences residual errors conditions. results disruption as result lighting reflects change surface-based higher-order processes.