title: Perception of three-dimensional shape from ego- and object-motion: comparison between small- and large-field stimuli.
abstract: We compare the performance in the detection of the shape of concave, planar and convex surfaces for small-field (8 deg) and large-field (90 deg) stimuli. Shape is perceived from head translations, object translations and object rotations. We find large differences between small-field and large-field stimulation. For small-field stimulation performance is best for object rotation, intermediate for self-motion and worst for object translation. For large-field stimulation performance is similar across conditions. Few errors on the sign of the curvature are found for self-motion for both field sizes, indicating that self-motion information disambiguates the curvature sign. For object rotation with small-field stimulation, the concave-convex ambiguity is strong with many apparent deformations. In contrast, large-field curvature signs are always accurately reported, suggesting that the weight of the rigidity hypothesis depends on field size.
authors.affiliation: Laboratory of Medical Physics and Biophysics, University of Nijmegen, The Netherlands.
authors.forename: T M
authors.initials: TM
authors.lastname: Dijkstra
authors.forename: V
authors.initials: V
authors.lastname: Cornilleau-Pérès
authors.forename: C C
authors.initials: CC
authors.lastname: Gielen
authors.forename: J
authors.initials: J
authors.lastname: Droulez
mesh_terms: D003867:Depth Perception / Q000502:physiology*; D005556:Form Perception / Q000502:physiology*; D006257:Head; D006801:Humans; D008297:Male; D009068:Movement; D011434:Proprioception / Q000502:physiology; D012399:Rotation; D012684:Sensory Thresholds / Q000502:physiology; D014794:Visual Fields