Center-surround velocity-based segmentation: Speed, eccentricity, and timing of visual stimuli interact to determine interocular dominance

Abstract

We used a novel method to capture the spatial dominance pattern of competing motion fields at rivalry onset. When rivaling velocities were different, the participants reported center-surround segmentation: The slower stimuli often dominated in the center while faster motion persisted along the borders. The size of the central static/slow field scaled with the stimulus size. The central dominance was time-locked to the static stimulus onset but was disrupted if the dynamic stimulus was presented later. We then used the same stimuli as masks in an interocular suppression paradigm. The local suppression strengths were probed with targets at different eccentricities. Consistent with the centersurround segmentation, target speed and location interacted with mask velocities. Specifically, suppression power of the slower masks was nonhomogenous with eccentricity, providing a potential explanation for centersurround velocity-based segmentation. This interaction of speed, eccentricity, and timing has implications for motion processing and interocular suppression. The influence of different masks on which target features get suppressed predicts that some ''unconscious effects'' are not generalizable across masks and, thus, need to be replicated under various masking conditions.

Is Peripheral Motion Detection Affected by Myopia?

“…These studies have enriched our knowledge of the link between myopia and peripheral motion perception. However, considering that motion perception is influenced by a variety of factors, such as eccentricity ( Leibowitz et al, 1972 ; Rogers, 1972 ; Johnson and Leibowitz, 1974 ; Koenderink et al, 1978a , b ; McKee and Nakayama, 1984 ; van de Grind et al, 1987 ; Wesemann and Norcia, 1992 ), spatial frequency ( Koenderink et al, 1978a , b ; van de Grind et al, 1987 ; Boulton and Baker, 1991 ; Beard et al, 1997 ; Bex and Dakin, 2003 ; Lappin et al, 2009 ), speed ( Lagae et al, 1993 ; Lappin et al, 2009 ; Ananyev et al, 2019 ), and the area in the different visual fields ( Kuo et al, 2018 ), it remains unclear that whether myopia affects peripheral motion processing and if so, whether the potential effect varied with these factors. In this study, we directly addressed this issue by measuring the motion detection thresholds of gratings in a four-alternative forced-choice task in blocks of eccentricity, spatial frequency, and speed in young adults with low to high myopia and emmetropes.…”