Perceptual resolution of ambiguous neural representations for form and chromaticity

Abstract

A coherent percept of our visual world is important for functioning. Ambiguities, however, are implicit in visual neural representations and must be resolved for stable perception of objects and scenes. Grouping processes can link multiple neurally ambiguous fragments across the visual field. Experiments here determined how multiple visual features of each fragment contribute to perceptual resolution of ambiguity by grouping. Chromatic interocular-switch rivalry, a technique for presenting competing dichoptic images, was used to induce ambiguous neural representations for equiluminant chromatic discs and gratings. Two dichoptic stimuli were presented simultaneously to measure the amount of time they both appeared the same in at least one feature domain. The two stimuli were grouped when they appeared to share ambiguous features such as color, orientation, and spatial frequency more often than chance. Experiments here tested whether unshared and unambiguous features impeded grouping of the ambiguous components. Overall, the results show that grouping can be driven by neural ambiguity that is common for fragments across the visual field, even when the fragments also have other unshared, unambiguous features.

Binocularly-driven competing neural responses and the perceptual resolution of color

“…An alternative theory, stimulus rivalry, argues that neural competition is between representations of the two stimuli. These representations can be at the level of binocularly driven neurons ( Figure 1 ) so stimulus rivalry may be resolved by competition between binocularly integrated neural responses with each response selectively tuned to one dichoptic stimulus ( Logothetis et al, 1996 ; Wilson, 2003 ; Christiansen, D’Antona, & Shevell, 2017 ; Slezak & Shevell, 2018 ; Slezak, Coia, & Shevell, 2019 ). Applying this approach to rivalrous chromaticities implies competition between separate binocularly driven neural representations that evoke either a red or a green percept.…”