A New Angle on Object-Background Effects in Vection.

Juno Kim,Michael T T Tran

doi:10.1177/2041669516631695

Abstract

We considered whether optic flow generated by 3D relief of a foreground surface might influence visually-mediated self-motion perception (vection). We generated background motion consistent with self-rotation, and a foreground object with bumpy relief was either rotated with the observer (ego-centric) or fixed in world coordinates (world-centric). We found that vection strength ratings were greater in conditions with world-centric retinal motion of the foreground object, despite generating flow that was opposite to background motion. This effect was explained by observer judgments of the axis self-rotation in depth; whereas ego-centric flow generated experiences of more on-axis self-rotation, world-centric flow generated experiences of centrifugal rotation around the foreground object. These data suggest that foreground object motion can increase the perception of self-motion generated by optic flow, even when they reduce net retinal motion coherence and promote conditions for multisensory conflict. This finding supports the view that self-motion perception depends on mid-level representations of whole-scene motion.

Highlights

We considered whether optic flow generated by 3D relief of a foreground surface might influence visually-mediated self-motion perception
Ohmi et al (1987) obtained similar findings, and Ohmi and Howard (1988) extended the effect to linear vection in depth generated by looming optic flow; a stationary pattern facilitated vection when perceived in the foreground, but suppressed vection when perceived behind the looming optic flow pattern
In support of the view that vection is influenced by perceived axis of self-rotation, there was a significant correlation between vection strength and perceived axis of rotation in depth, r 1⁄4 þ0.56, t(30) 1⁄4 3.75, p < .001. This relationship suggests that approximately 31% of the variability in vection strength estimates is explainable by variations in the perceived axis of self-rotation

Summary

Introduction

We considered whether optic flow generated by 3D relief of a foreground surface might influence visually-mediated self-motion perception (vection). The primary visual stimulus for self-motion perception is ‘‘optic flow,’’ which is generated by the light reflected by the surfaces of objects that move relative to the observer (Gibson, 1950). Seno et al (2009) proposed these effects support the hypothesis that vection is driven by motion perceived in the background and not the foreground.

Results

Conclusion