Amodal completion with background determines depth from monocular gap stereopsis

Grove, Gillam, and Ono [Grove, P. M., Gillam, B. J., & Ono, H. (2002). Content and context of monocular regions determine perceived depth in random dot, unpaired background and phantom stereograms. Vision Research, 42, 1859-1870] reported that perceived depth in monocular gap stereograms [Gillam, B. J., Blackburn, S., & Nakayama, K. (1999). Stereopsis based on monocular gaps: Metrical encoding of depth and slant without matching contours. Vision Research, 39, 493-502] was attenuated when the color/texture in the monocular gap did not match the background. It appears that continuation of the gap with the background constitutes an important component of the stimulus conditions that allow a monocular gap in an otherwise binocular surface to be responded to as a depth step. In this report we tested this view using the conventional monocular gap stimulus of two identical grey rectangles separated by a gap in one eye but abutting to form a solid grey rectangle in the other. We compared depth seen at the gap for this stimulus with stimuli that were identical except for two additional small black squares placed at the ends of the gap. If the squares were placed stereoscopically behind the rectangle/gap configuration (appearing on the background) they interfered with the perceived depth at the gap. However when they were placed in front of the configuration this attenuation disappeared. The gap and the background were able under these conditions to complete amodally.

[1]  D G Pelli,et al.  The VideoToolbox software for visual psychophysics: transforming numbers into movies. , 1997, Spatial vision.

[2]  R. Fleming,et al.  The Interpolation of Object and Surface Structure , 2002, Cognitive Psychology.

[3]  Hiroshi Ono,et al.  Content and context of monocular regions determine perceived depth in random dot, unpaired background and phantom stereograms , 2002, Vision Research.

[4]  Philip J Kellman,et al.  Surface integration influences depth discrimination , 2000, Vision Research.

[5]  K Nakayama,et al.  Experiencing and perceiving visual surfaces. , 1992, Science.

[6]  I. Howard,et al.  Seeing in depth, Vol. 2: Depth perception. , 2002 .

[7]  Michael J Pianta,et al.  Paired and unpaired features can be equally effective in human depth perception , 2003, Vision Research.

[8]  Philip M. Grove,et al.  Slant or occlusion: global factors resolve stereoscopic ambiguity in sets of horizontal lines , 2004, Vision Research.

[9]  D H Brainard,et al.  The Psychophysics Toolbox. , 1997, Spatial vision.

[10]  V S Ramachandran,et al.  Capture of stereopsis and apparent motion by illusory contours , 1986, Perception & psychophysics.

[11]  Barbara J Gillam,et al.  Monocular gap stereopsis: manipulation of the outer edge disparity and the shape of the gap , 2003, Vision Research.

[12]  Jaakko Hintikka,et al.  On the Logic of Perception , 1969 .

[13]  B. Julesz,et al.  A THEORETICAL ANALYSIS OF ILLUSORY CONTOUR FORMATION IN STEREOPSIS , 1995 .

[14]  B. Gillam,et al.  How Configurations of Binocular Disparity Determine Whether Stereoscopic Slant or Stereoscopic Occlusion is Seen , 2005, Perception.