Binocular rivalry of spiral and linear moving random dot patterns in human observers

Abstract

Binocular rivalry describes the alternating perception of two competing monocular images. It is hypothesized to arise at multiple levels of the visual pathway due to competition between neuronal populations representing the displayed images. We tested whether an enhanced neural representation of expanding motion yields a bias over other spiral motion (i.e., contraction and rotation) and linear motion stimuli during binocular rivalry. We presented random dot patterns of different motion types (i.e., linear and spiral), matched in contrast and speed, to human subjects through a mirror stereoscope. During spiral rivalry, expansion rivalry periods dominated over those of contraction and rotation, and contraction dominated over rotation. During linear motion rivalry, up, down, left, and right directions had similar rivalry periods. All spiral motions dominated over linear motions. Interestingly, when these motion types rivaled against each other, the rivalry periods of spiral motion slightly decreased while those of linear motion significantly increased. This rivalry also caused the bias for expansion relative to other spirals to disappear. Our results suggest a correlation between neuronal representations of different moving patterns and their perception during binocular motion rivalry and provide further evidence that rivalry periods are constrained by the ecologic relevance of stimuli.

Does direction of walking impact binocular rivalry between competing patterns of optic flow?

“…This realization led us to analyze EXP and CON dominance durations measured during the sitting condition in Experiments 2 and 3, where one's own actions do not imply self-production of optic flow on the retina. In that combined data set, EXP dominance durations were significantly longer than were CON durations (3.72 vs 3.175 s, T-test P = .003, ks-test P = .00006), mirroring earlier findings (Conrad et al, 2013;Malek et al, 2012; but see Parker & Alais, 2007). So, perhaps walking vetoes the sense of looming and pending collision signified by centrifugal radial motion viewed by a stationary observer.…”

“…3a), and they are accompanied by intervening periods of mixtures. We would note, too, that other studies of motion-induced rivalry have successfully used RDCs of the sort we employed (Blake et al, 1985(Blake et al, , 1998Chen et al, 2001;Parker & Alais, 2007;Malek et al, 2012;Holten et al, 2015). We are thus satisfied that the stimuli we employed are sufficient to generate robust binocular rivalry.…”

“…5d confirms that RAN durations were slightly longer than EXP and CON durations. An earlier study of rivalry between dissimilar, structured motion viewed by stationary observers did not include RAN among their stimuli, so we cannot meaningfully compare our results to theirs (Malek et al, 2012).…”

“…Ours is not the first study to employ complex optic flow patterns as rival stimuli, but it is the first to do so in the context of self-motion. In several earlier studies using rival targets simulating complex motion patterns, it was found that visual motion simulating expansion enjoyed a bias during rivalry over dots simulating contraction, although there was some disagreement among these studies about the specific dependence of that bias on the form of the motion stimuli (Parker & Alais, 2007;Malek et al, 2012;Conrad et al, 2013;Holten et al, 2015). Our aim, however, was to learn whether the predominance of expansion and contraction was dependent on one's walking direction.…”

Visual Directional Anisotropy Does Not Mirror the Directional Anisotropy Apparent in Postural Sway

“…Another study has showed that counter phase gratings with equal motion components in both directions appeared to drift foveofugally rather than foveopetally (Georgeson & Harris, 1978). Also, longer dominance durations for expanding optic flow compared with contracting optic flow are reported during binocular rivalry (Malek et al, 2012;Parker & Alais, 2007). However, this apparent greater perceptual strength of expanding motion is opposite to what we expected based on the direction of the anisotropy in postural sway, and it is also opposite to the results of previous studies reporting a lower threshold for contracting than for expanding optic flow (Edwards & Badcock, 1993;Edwards & Ibbotson, 2007).…”