Stereoscopic depth processing in the visual cortex: a coarse-to-fine mechanism

10.1038/nn986 ◽  
2002 ◽  
Vol 6 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Michael D. Menz ◽  
Ralph D. Freeman
Keyword(s):  
Visual Cortex ◽  
Stereoscopic Depth ◽  
Depth Processing ◽  
Coarse To Fine

Stereoscopic depth discrimination in the visual cortex: neurons ideally suited as disparity detectors

Science ◽  
1990 ◽  
Vol 249 (4972) ◽  
pp. 1037-1041 ◽  
Author(s):  
I Ohzawa ◽  
G. DeAngelis ◽  
R. Freeman
Keyword(s):  
Visual Cortex ◽  
Stereoscopic Depth ◽  
Depth Discrimination ◽  
Visual Cortex Neurons

scholarly journals Adaptation Changes Stereoscopic Depth Selectivity in Visual Cortex

2011 ◽  
Vol 31 (34) ◽  
pp. 12198-12207
Author(s):  
T. Duong ◽  
B. D. Moore ◽  
R. D. Freeman
Keyword(s):  
Visual Cortex ◽  
Stereoscopic Depth

A time-based stereoscopic depth mechanism in the visual cortex

1985 ◽  
Vol 328 (1) ◽  
pp. 154-157 ◽  
Author(s):  
Jill C. Gardner ◽  
Robert M. Douglas ◽  
Max S. Cynader
Keyword(s):  
Visual Cortex ◽  
Stereoscopic Depth

Stereopsis and Depth Perception

2019 ◽  
Author(s):  
Andrew J. Parker
Keyword(s):  
Nervous System ◽  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Stereoscopic Vision ◽  
Stereoscopic Depth ◽  
Extrastriate Cortex ◽  
Ecological Niches ◽  
Relative Depth ◽  
Subsequent Work ◽  
Binocular Depth

Humans and some animals can use their two eyes in cooperation to detect and discriminate parts of the visual scene based on depth. Owing to the horizontal separation of the eyes, each eye obtains a slightly different view of the scene in front of the head. These small differences are processed by the nervous system to generate a sense of binocular depth. As humans, we experience an impression of solidity that is fully three-dimensional; this impression is called stereopsis and is what we appreciate when we watch a 3D movie or look into a stereoscopic viewer. While the basic perceptual phenomena of stereoscopic vision have been known for some time, it is mainly within the last 50 years that we have gained an understanding of how the nervous system delivers this sense of depth. This period of research began with the identification of neuronal signals for binocular depth in the primary visual cortex. Building on that finding, subsequent work has traced the signaling pathways for binocular stereoscopic depth forward into extrastriate cortex and further on into cortical areas concerning with sensorimotor integration. Within these pathways, neurons acquire sensitivity to more complex, higher order aspects of stereoscopic depth. Signals relating to the relative depth of visual features can be identified in the extrastriate cortex, which is a form of selectivity not found in the primary visual cortex. Over the same time period, knowledge of the organization of binocular vision in animals that inhabit a wide diversity of ecological niches has substantially increased. The implications of these findings for developmental and adult plasticity of the visual nervous system and onset of the clinical condition of amblyopia are explored in this article. Amblyopic vision is associated with a cluster of different visual and oculomotor symptoms, but the loss of high-quality stereoscopic depth performance is one of the consistent clinical features. Understanding where and how those losses occur in the visual brain is an important goal of current research, for both scientific and clinical reasons.

scholarly journals Neural mechanisms of coarse-to-fine discrimination in the visual cortex

2014 ◽  
Vol 112 (11) ◽  
pp. 2822-2833 ◽  
Author(s):  
Gopathy Purushothaman ◽  
Xin Chen ◽  
Dmitry Yampolsky ◽  
Vivien A. Casagrande
Keyword(s):  
Visual Cortex ◽  
Tuning Curve ◽  
Discrimination Performance ◽  
Neural Mechanisms ◽  
Initial Increase ◽  
Group 2 ◽  
The Right ◽  
Neuronal Groups ◽  
Coarse To Fine ◽  
Group 1

Vision is a dynamic process that refines the spatial scale of analysis over time, as evidenced by a progressive improvement in the ability to detect and discriminate finer details. To understand coarse-to-fine discrimination, we studied the dynamics of spatial frequency (SF) response using reverse correlation in the primary visual cortex (V1) of the primate. In a majority of V1 cells studied, preferred SF either increased monotonically with time ( group 1) or changed nonmonotonically, with an initial increase followed by a decrease ( group 2). Monotonic shift in preferred SF occurred with or without an early suppression at low SFs. Late suppression at high SFs always accompanied nonmonotonic SF dynamics. Bayesian analysis showed that SF discrimination performance and best discriminable SF frequencies changed with time in different ways in the two groups of neurons. In group 1 neurons, SF discrimination performance peaked on both left and right flanks of the SF tuning curve at about the same time. In group 2 neurons, peak discrimination occurred on the right flank (high SFs) later than on the left flank (low SFs). Group 2 neurons were also better discriminators of high SFs. We examined the relationship between the time at which SF discrimination performance peaked on either flank of the SF tuning curve and the corresponding best discriminable SFs in both neuronal groups. This analysis showed that the population best discriminable SF increased with time in V1. These results suggest neural mechanisms for coarse-to-fine discrimination behavior and that this process originates in V1 or earlier.

scholarly journals Activation in Visual Cortex Correlates with the Awareness of Stereoscopic Depth

2005 ◽  
Vol 25 (45) ◽  
pp. 10403-10413 ◽  
Author(s):  
G. J. Brouwer
Keyword(s):  
Visual Cortex ◽  
Stereoscopic Depth

scholarly journals Stereoscopic Depth Perception Using a Model Based on the Primary Visual Cortex

PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e80745 ◽  
Author(s):  
Fernanda da C. e C. Faria ◽  
Jorge Batista ◽  
Helder Araújo
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Depth Perception ◽  
Stereoscopic Depth ◽  
Model Based

Coarse-to-Fine Processing Drives the Efficient Coding of Natural Scenes in Mouse Visual Cortex

2021 ◽  
Author(s):  
Rolf Skyberg ◽  
Seiji Tanabe ◽  
Hui Chen ◽  
Jianhua Cang
Keyword(s):  
Visual Cortex ◽  
Natural Scenes ◽  
Efficient Coding ◽  
Mouse Visual Cortex ◽  
Coarse To Fine

scholarly journals Human Cortical Activity Correlates With Stereoscopic Depth Perception

2001 ◽  
Vol 86 (4) ◽  
pp. 2054-2068 ◽  
Author(s):  
Benjamin T. Backus ◽  
David J. Fleet ◽  
Andrew J. Parker ◽  
David J. Heeger
Keyword(s):  
Visual Cortex ◽  
Depth Perception ◽  
Cortical Activity ◽  
Stereoscopic Depth ◽  
Extrastriate Cortex ◽  
Fmri Data ◽  
Special Role ◽  
Single Neurons ◽  
Depth Limit ◽  
Electrophysiological Recordings

Stereoscopic depth perception is based on binocular disparities. Although neurons in primary visual cortex (V1) are selective for binocular disparity, their responses do not explicitly code perceived depth. The stereoscopic pathway must therefore include additional processing beyond V1. We used functional magnetic resonance imaging (fMRI) to examine stereo processing in V1 and other areas of visual cortex. We created stereoscopic stimuli that portrayed two planes of dots in depth, placed symmetrically about the plane of fixation, or else asymmetrically with both planes either nearer or farther than fixation. The interplane disparity was varied parametrically to determine the stereoacuity threshold (the smallest detectable disparity) and the upper depth limit (largest detectable disparity). fMRI was then used to quantify cortical activity across the entire range of detectable interplane disparities. Measured cortical activity covaried with psychophysical measures of stereoscopic depth perception. Activity increased as the interplane disparity increased above the stereoacuity threshold and dropped as interplane disparity approached the upper depth limit. From the fMRI data and an assumption that V1 encodes absolute retinal disparity, we predicted that the mean response of V1 neurons should be a bimodal function of disparity. A post hoc analysis of electrophysiological recordings of single neurons in macaques revealed that, although the average firing rate was a bimodal function of disparity (as predicted), the precise shape of the function cannot fully explain the fMRI data. Although there was widespread activity within the extrastriate cortex (consistent with electrophysiological recordings of single neurons), area V3A showed remarkable sensitivity to stereoscopic stimuli, suggesting that neurons in V3A may play a special role in the stereo pathway.

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