Simulated forward and backward self motion, based on realistic parameters, causes motion induced blindness

Victoria Thomas,Jeroen Van Boxtel,Parisa Zakavi,Naotsugu Tsuchiya,Matthew Davidson

doi:10.1038/s41598-017-09424-6

Abstract

Motion Induced Blindness (MIB) is a well-established visual phenomenon whereby highly salient targets disappear when viewed against a moving background mask. No research has yet explored whether contracting and expanding optic flow can also trigger target disappearance. We explored MIB using mask speeds corresponding to driving at 35, 50, 65 and 80 km/h in simulated forward (expansion) and backward (contraction) motion as well as 2-D radial movement, random, and static mask motion types. Participants (n = 18) viewed MIB targets against masks with different movement types, speed, and target locations. To understand the relationship between saccades, pupil response and perceptual disappearance, we ran two additional eye-tracking experiments (n = 19). Target disappearance increased significantly with faster mask speeds and upper visual field target presentation. Simulated optic flow and 2-D radial movement caused comparable disappearance, and all moving masks caused significantly more disappearance than a static mask. Saccades could not entirely account for differences between conditions, suggesting that self-motion optic flow does cause MIB in an artificial setting. Pupil analyses implied that MIB disappearance induced by optic flow is not subjectively salient, potentially explaining why MIB is not noticed during driving. Potential implications of MIB for driving safety and Head-Up-Display (HUD) technologies are discussed.

Highlights

Motion Induced Blindness (MIB) is a visual phenomenon whereby highly salient visual targets become temporarily invisible despite their ongoing physical presence in one’s visual field, when viewed against the background of a global moving mask[1]
We investigated the duration of MIB disappearance with optic flow patterns in two samples of non-overlapping subjects (Experiment 1: n = 18; Experiment 2: n = 19, see Method) comparing masks simulating forward and backward self motion with a static stimulus
Various other motion patterns have been used in the past[1, 19,20,21], but none have used a contracting or expanding optic flow analogous to when walking or driving, despite cues of self-motion being essential to safe navigation[34]

Summary

Introduction

Motion Induced Blindness (MIB) is a visual phenomenon whereby highly salient visual targets become temporarily invisible despite their ongoing physical presence in one’s visual field, when viewed against the background of a global moving mask[1]. Shimojo[9] used a mirror ball to create a moving mask of bright spots across a room, and was able to cause the perceptual disappearance of a live person in their interactive museum display Another demonstration of MIB in real life was reported by Inoue, Yagi and Kikuchi[10], where they induced MIB by superimposing a target over the optic flow of a movie, filmed from the driver’s point of view while travelling in a car. Our own pilot studies have informally replicated this finding This evidence suggests that the optical flow experienced in forward self motion can induce MIB in situations where a stable image is projected to the retina over a moving background. No study has explored variations in the speed of masks that contract or expand in a way that occurs during self-motion

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Conclusion