How vertical disparities assist judgements of distance

The ratio of the vertical sizes of corresponding features in the two eyes' retinal images depends both on the associated object's distance and on its horizontal direction relative to the head (eccentricity). It is known that manipulations of vertical size ratio can affect perceived distance, size, depth and shape. We examined how observers use the vertical size ratio to determine the viewing distance. Do they use the horizontal gradient of vertical size ratio, or do they combine the vertical size ratio itself with the eccentricity at which it is found? Distance scaling (as measured by having subjects set an ellipsoid's size and shape to match a tennis ball) was no better when the judged object was 30 degrees to the right of the head (where vertical size ratios vary considerably with distance) than when it was located straight ahead. Distance scaling improved when vertical disparities were presented within larger visual fields, irrespective of where this was relative to the head. Our results support the proposal that subjects use the horizontal gradient of vertical size ratio to estimate the distance of an object that they are looking at.

[1]  Eli Brenner,et al.  Comparing extra-retinal information about distance and direction , 2000, Vision Research.

[2]  M F Bradshaw,et al.  Vertical disparities, differential perspective and binocular stereopsis , 1993, Nature.

[3]  E. Brenner,et al.  Judging distance from ocular convergence , 1998, Vision Research.

[4]  P O Bishop,et al.  Vertical disparity, egocentric distance and stereoscopic depth constancy: a new interpretation , 1989, Proceedings of the Royal Society of London. B. Biological Sciences.

[5]  J. E. W. Mayhew,et al.  A computational model of binocular depth perception , 1982, Nature.

[6]  G Westheimer,et al.  Detection and processing of vertical disparity by the human observer , 1992, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[7]  T. Collett,et al.  Does vertical disparity scale the perception of stereoscopic depth? , 1991, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[8]  Carlos Acuña,et al.  Cell responses to vertical and horizontal retinal disparities in the monkey visual cortex , 1993, Neuroscience Letters.

[9]  Martin S. Banks,et al.  Extra-retinal and perspective cues cause the small range of the induced effect , 1998, Vision Research.

[10]  B. Gillam,et al.  The induced effect, vertical disparity, and stereoscopic theory , 1983, Perception & psychophysics.

[11]  Casper J. Erkelens,et al.  A computational model of depth perception based on headcentric disparity , 1998, Vision Research.

[12]  John Porrill,et al.  Robust and optimal use of information in stereo vision , 1999, Nature.

[13]  M F Bradshaw,et al.  Disparity Scaling and the Perception of Frontoparallel Surfaces , 1995, Perception.

[14]  E. Johnston.  Systematic distortions of shape from stereopsis , 1991, Vision Research.

[15]  M. Landy,et al.  Interaction between the perceived shape of two objects , 1999, Vision Research.

[16]  C. Erkelens,et al.  Stability of Binocular Depth Perception with Moving Head and Eyes , 1996, Vision Research.

[17]  J. Smol,et al.  Rapid response of treeline vegetation and lakes to past climate warming , 1993, Nature.

[18]  R. S Allison,et al.  Depth selectivity of vertical fusional mechanisms , 2000, Vision Research.

[19]  James A. Crowell,et al.  Horizontal and vertical disparity, eye position, and stereoscopic slant perception , 1999, Vision Research.

[20]  B. Rogers,et al.  The effect of display size on disparity scaling from differential perspective and vergence cues , 1996, Vision Research.

[21]  M. Banks,et al.  Estimator Reliability and Distance Scaling in Stereoscopic Slant Perception , 1999, Perception.

[22]  I. Howard,et al.  Relative Size Disparities and the Perception of Surface Slant , 1996, Vision Research.

[23]  John P. Frisby.  Vision: An old illusion and a new theory of stereoscopic depth perception , 1984, Nature.

[24]  B. G. Cumming,et al.  Vertical disparities and perception of three-dimensional shape , 1991, Nature.

[25]  J. E. W. Mayhew,et al.  Vertical disparity pooling and the induced effect , 1984, Nature.

[26]  S. D. Hippisley-Cox,et al.  Pooling of Vertical Disparities by the Human Visual System , 1996, Perception.

[27]  E. Brenner,et al.  The Distance Used for Scaling Disparities is the Same as the One Used for Scaling Retinal Size , 1997, Vision Research.

[28]  B Gillam,et al.  The role of vertical disparity in the scaling of stereoscopic depth perception: An empirical and theoretical study , 1988, Perception & psychophysics.