Citation

Niehorster DC, Li L. Iperception 2017; 8(3): e2041669517708206.

Affiliation

Department of Psychology, The University of Hong Kong, Pokfulam, Hong Kong; Neural Science Program, NYU-ECNU Institute of Brain and Cognitive Science, New York University Shanghai, China.

Copyright

(Copyright © 2017, SAGE Publishing)

DOI

10.1177/2041669517708206

PMID

28567272

PMCID

PMC5439648

Abstract

How do we perceive object motion during self-motion using visual information alone? Previous studies have reported that the visual system can use optic flow to identify and globally subtract the retinal motion component resulting from self-motion to recover scene-relative object motion, a process called flow parsing. In this article, we developed a retinal motion nulling method to directly measure and quantify the magnitude of flow parsing (i.e., flow parsing gain) in various scenarios to examine the accuracy and tuning of flow parsing for the visual perception of object motion during self-motion. We found that flow parsing gains were below unity for all displays in all experiments; and that increasing self-motion and object motion speed did not alter flow parsing gain. We conclude that visual information alone is not sufficient for the accurate perception of scene-relative motion during self-motion. Although flow parsing performs global subtraction, its accuracy also depends on local motion information in the retinal vicinity of the moving object. Furthermore, the flow parsing gain was constant across common self-motion or object motion speeds. These results can be used to inform and validate computational models of flow parsing.

Language: en

Keywords

flow parsing; global motion; optic flow; self-motion; speed tuning