These findings help characterize how stimulus rivalry fits within hierarchical models of binocular rivalry.Parallax affects an object's apparent position based on the distance and change of position from and of the observer. In sum, only binocular rivalry produced perceptually vivid alternations, increased activation of the early visual cortex, and the coordinated engagement of dorsal stream regions, even when a task was not performed. While both types of rivalry engaged higher tier visual regions such as the ventral temporal cortex during an active task, activity for stimulus rivalry was comparatively weak in early visual areas V1 to V3, presumably due to a weaker feed-forward signal due to both intraocular and interocular inhibition that may reduce effective contrast. In particular, the right superior parietal cortex and the right temporoparietal junction were prominently engaged for passive binocular rivalry.
Overall, we found that activity for binocular rivalry was always stronger and more widespread than that for stimulus rivalry-even more so during passive viewing conditions. Here, we used functional magnetic resonance imaging to directly compare brain activity underlying the two types of perceptual rivalry. In stimulus rivalry, similar perceptual alternations between rival images can occur even in the midst of fast image swapping between the eyes. When incompatible images are presented to each eye, a phenomenon known as binocular rivalry occurs in which the viewer's conscious visual perception alternates between the two images. In sum, we present a Bayesian model that provides a parsimonious account for a range of systematic misperceptions of motion in naturalistic environments. These errors include a lateral bias in perceived motion direction and a surprising tendency to misreport approaching motion as receding and vice versa. As predicted, we found evidence that errors in 3-D motion perception depend on the contrast, viewing distance, and eccentricity of a stimulus.
#LACK OF MOTION PARALLAX SERIES#
We then used a virtual-reality headset as well as a standard 3-D desktop stereoscopic display to test these predictions in a series of perceptual experiments. The model predicts a set of systematic perceptual errors, which depend on stimulus distance, contrast, and eccentricity. Next, we developed a Bayesian model, treating 3-D motion perception as optimal inference given sensory noise in the measurement of retinal motion. To do so, we characterized the binocular retinal motion signals produced by objects moving through arbitrary locations in 3-D. Here, we provide a unified explanation for systematic errors in the perception of three-dimensional (3-D) motion. People make surprising but reliable perceptual errors. In conclusion, depth ordering performance is enhanced by all of the dynamic perspective cues but not by using more naturalistic 1/f textures. Removal of any of the three cues impaired performance. We also examined the effects of removing each of the three cues that distinguish dynamic perspective from orthographic rendering: (a) small vertical displacements, (b) lateral gradients of speed across the corrugations, and (c) speed differences in rendered near versus far surfaces. Depth ordering performance with naturalistic 1/f textures was slightly lower than with the random dots however, with depth-related size scaling of the micropatterns, performance was comparable to that with random dots.
For both textures, depth perception was better with dynamic perspective than with orthographic rendering, particularly at larger depths. Four observers performed a two-alternative forced choice depth ordering task with monocular viewing, in which they reported which part of the texture appeared in front of the other. Relative texture motion (shearing) with square wave corrugation patterns was synchronized to horizontal head movement. We compared depth perception for orthographic and perspective rendering, using textures composed of two types of elements: random dots and Gabor micropatterns. Here we examine depth from motion parallax in more naturalistic conditions using textures with an overall 1/f spectrum and dynamic perspective rendering. Motion parallax, the perception of depth resulting from an observer's self-movement, has almost always been studied with random dot textures in simplified orthographic rendering.
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