Comparison of motion and stereopsis: linear and nonlinear performance.
To address the issue of whether the luminance-dependent (linear) and contrast-dependent (nonlinear) processes in stereo and motion have a common computational basis, we compare both carrier-dependent and envelope-dependent performance for these two modalities by using the same stimulus and task: two-flash apparent motion/depth for a wide range of displacements. We do this for different densities, bandwidths, contrasts, spatial frequencies, and exposure durations. The results suggest that there is concordance not only between the luminance-dependent (linear) processes of motion and stereo but also between the envelope-dependent (nonlinear) processes of both modalities. Only one exception was found, but we show this to be amenable to an explanation based on a different contrast dependence for the nonlinear mechanisms of stereo and motion. This suggests that the computational basis of linear and nonlinear processes may be similar for stereopsis and motion.
Hess
R F
RF
Department of Ophthalmology, McGill University, Montreal, Quebec, Canada. rhess@vision.mcgill.ca
Baker
C L
CL
Wilcox
L M
LM
D003867:Depth Perception / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008960:Models, Psychological; D009039:Motion Perception / Q000502:physiology*; D017711:Nonlinear Dynamics; D010775:Photic Stimulation