Optimal smoothing in visual motion perception

Citation
Rpn. Rao et al., Optimal smoothing in visual motion perception, NEURAL COMP, 13(6), 2001, pp. 1243-1253
Citations number
27
Categorie Soggetti
Neurosciences & Behavoir","AI Robotics and Automatic Control
Journal title
NEURAL COMPUTATION
ISSN journal
08997667 → ACNP
Volume
13
Issue
6
Year of publication
2001
Pages
1243 - 1253
Database
ISI
SICI code
0899-7667(200106)13:6<1243:OSIVMP>2.0.ZU;2-Y
Abstract
When a flash is aligned with a moving object, subjects perceive the flash t o lag behind the moving object. Two different models have been proposed to explain this "flash-lag" effect. In the motion extrapolation model, the vis ual system extrapolates the location of the moving object to counteract neu ral propagation delays, whereas in the latency difference model, it is hypo thesized that moving objects are processed and perceived more quickly than flashed objects. However, recent psychophysical experiments suggest that ne ither of these interpretations is feasible (Eagleman & Sejnowski, 2000a, 20 00b, 2000c), hypothesizing instead that the visual system uses data from th e future of an event before committing to an interpretation. We formalize t his idea in terms of the statistical framework of optimal smoothing and sho w that a model based on smoothing accounts for the shape of psychometric cu rves from a flash-lag experiment involving random reversals of motion direc tion. The smoothing model demonstrates how the visual system may enhance pe rceptual accuracy by relying not only on data from the past but also on dat a collected from the immediate future of an event.