General Validity of Levelt's Propositions Reveals Common Computational Mechanisms for Visual Rivalry

P Christiaan Klink,Raymond Van Ee,Richard J A Van Wezel,David C Burr

doi:10.1371/journal.pone.0003473

Abstract

The mechanisms underlying conscious visual perception are often studied with either binocular rivalry or perceptual rivalry stimuli. Despite existing research into both types of rivalry, it remains unclear to what extent their underlying mechanisms involve common computational rules. Computational models of binocular rivalry mechanisms are generally tested against Levelt's four propositions, describing the psychophysical relation between stimulus strength and alternation dynamics in binocular rivalry. Here we use a bistable rotating structure-from-motion sphere, a generally studied form of perceptual rivalry, to demonstrate that Levelt's propositions also apply to the alternation dynamics of perceptual rivalry. Importantly, these findings suggest that bistability in structure-from-motion results from active cross-inhibition between neural populations with computational principles similar to those present in binocular rivalry. Thus, although the neural input to the computational mechanism of rivalry may stem from different cortical neurons and different cognitive levels the computational principles just prior to the production of visual awareness appear to be common to the two types of rivalry.

Highlights

In a world that provides an abundance of visual information our brain seemingly effortlessly decides which information reaches awareness
Stimulus strength and perceptual interpretation are tightly coupled in perceptual rivalry, but unlike in binocular rivalry they are not exactly similar
We have shown that crucial constraints for binocular rivalry models inspired by Levelt’s four propositions can just as well be applied to the perceptual rivalry of a bistable rotating structure-from-motion sphere

Summary

Introduction

In a world that provides an abundance of visual information our brain seemingly effortlessly decides which information reaches awareness. In the lab, this process can be studied using stimuli that cause perception to alternate between competing interpretations while staying constant on the retina [1]. This process can be studied using stimuli that cause perception to alternate between competing interpretations while staying constant on the retina [1] Two categories of such stimuli can be distinguished. In binocular rivalry the two eyes are independently presented with different visual stimuli (e.g. dissimmilarly oriented gratings), causing either eye’s image to be perceived in turn. Binocular and perceptual rivalry are both manifestations of how the visual system handles inconclusive sensory evidence, but it remains unclear whether they include common computational mechanisms

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