Perceiving visual expansion without optic flow

Paul R. Schrater (), David C. Knill and Eero P. Simoncelli
Additional contact information
Paul R. Schrater: University of Pennsylvania, 215 Stemmler Hall
David C. Knill: University of Pennsylvania
Eero P. Simoncelli: Howard Hughes Medical Institute and Center for Neural Science and Mathematics, New York University

Nature, 2001, vol. 410, issue 6830, 816-819

Abstract: Abstract When an observer moves forward in the environment, the image on his or her retina expands. The rate of this expansion conveys information about the observer's speed1 and the time to collision2,3,4. Psychophysical5,7 and physiological8,9 studies have provided abundant evidence that these expansionary motions are processed by specialized mechanisms in mammalian visual systems. It is commonly assumed that the rate of expansion is estimated from the divergence of the optic-flow field (the two-dimensional field of local translational velocities)10,11,12,13,14. But this rate might also be estimated from changes in the size (or scale) of image features15. To determine whether human vision uses such scale-change information, we have synthesized stochastic texture stimuli in which the scale of image elements increases gradually over time, while the optic-flow pattern is random. Here we show, using these stimuli, that observers can estimate expansion rates from scale-change information alone, and that pure scale changes can produce motion after-effects. These two findings suggest that the visual system contains mechanisms that are explicitly sensitive to changes in scale.

Date: 2001
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/35071075 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:410:y:2001:i:6830:d:10.1038_35071075

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/35071075

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().