scholarly journals Cellular organization of visual information processing channels in the mouse visual cortex

2018 ◽  
Author(s):  
Xu Han ◽  
Ben Vermaercke ◽  
Vincent Bonin
Keyword(s):  
Information Processing ◽  
Functional Diversity ◽  
Visual Processing ◽  
Visual Information ◽  
Visual Representations ◽  
Data Sets ◽  
Visual Areas ◽  
Motion Speed ◽  
Information Channels ◽  
Spatiotemporal Tuning

AbstractVisual processing and behavior depend on specialized neural representations and information channels that encode distinct visual information and enable distinct computations. Our understanding of the neural substrate, however, remain severely limited by sparse recordings and the restricted range of visual areas and visual stimuli considered. We characterized in the mouse the multidimensional spatiotemporal tuning properties of > 30,000 layer 2/3 pyramidal neurons across seven areas of the cortex. The dataset reveals population specialized for processing of oriented and non-oriented contrast, spatiotemporal frequency, and motion speed. Areal analysis reveals profound functional diversity and specificity as well as highly specific representations of visual processing channels in distinct visual areas. Clustering analysis shows a branching of visual representations along the posterior to anterior axis, and between lateral and dorsal areas. Overall, this dataset provides a cellular-resolution atlas for understanding organizing principles underlying sensory representations across the cortex.SummaryVisual representations and visual channels are the cornerstones of mammalian visual processing and critical for a range of life sustaining behaviors. However, the lack of data sets spanning multiple visual areas preclude unambiguous identification of visual processing streams and the sparse, singular recording data sets obtained thus far are insufficient to reveal the functional diversity of visual areas and to study visual information channels. We characterized the tunings of over 30,000 cortical excitatory neurons from 7 visual areas to a broad array of stimuli and studied their responses in terms of their ability to encode orientation, spatiotemporal contrast and visual motion speed. We found all mouse visual cortical areas convey diverse information but show distinct biases in terms of numbers of neurons tuned to particular spatiotemporal features. Neurons in visual areas differ in their spatiotemporal tuning but also in their relative response to oriented and unoriented contrast. We uncovered a population that preferentially responds to unoriented contrast and shows only weak responses to oriented stimuli. This population is strongly overrepresented in certain areas (V1, LM and LI) and underrepresented in others (AL, RL, AM, and PM). Spatiotemporal tunings are broadly distributed in all visual areas indicating that all areas have access to broad spatiotemporal information. However, individual areas show specific biases. While V1 is heavily biased in favor of low spatial and temporal frequencies, area LM responds more strongly to mid-range frequencies. Areas PM and LI are biased in favor of slowly-varying high-resolution signals. By comparison, anterior areas AL, RL and AM are heavily biased in favor of fast-varying, low to mid spatial frequency signals. Critically, theses biases express themselves in vastly different number of cells tuned to particular features, suggesting differential sampling of visual processing channels across areas. Comparing across areas, we found divergent visual representations between anterior and posterior areas, and between lateral and dorsal areas, suggesting the segregated organization of cortical streams for distinct information processing.

Effects of Symbol Structure on Visual Information Processing

1983 ◽  
Vol 27 (5) ◽  
pp. 354-354
Author(s):  
Bruce W. Hamill ◽  
Robert A. Virzi
Keyword(s):  
Information Processing ◽  
Visual Processing ◽  
Visual Information ◽  
Context Effects ◽  
Response Times ◽  
Search Time ◽  
Visual Information Processing ◽  
Array Size ◽  
Serial Search ◽  
Feature Structure

This investigation addresses the problem of attention in the processing of symbolic information from visual displays. Its scope includes the nature of attentive processes, the structural properties of stimuli that influence visual information processing mechanisms, and the manner in which these factors interact in perception. Our purpose is to determine the effects of configural feature structure on visual information processing. It is known that for stimuli comprising separable features, one can distinguish between conditions in which only one relevant feature differs among stimuli in the array being searched and conditions in which conjunctions of two (or more) features differ: Since the visual process of conjoining separable features is additive, this fact is reflected in search time as a function of array size, with feature conditions yielding flat curves associated with parallel search (no increase in search time across array sizes) and conjunction conditions yielding linearly increasing curves associated with serial search. We studied configural-feature stimuli within this framework to determine the nature of visual processing for such stimuli as a function of their feature structure. Response times of subjects searching for particular targets among structured arrays of distractors were measured in a speeded visual search task. Two different sets of stimulus materials were studied in array sizes of up to 32 stimuli, using both tachistoscope and microcomputer-based CRT presentation for each. Our results with configural stimuli indicate serial search in all of the conditions, with the slope of the response-time-by-array-size function being steeper for conjunction conditions than for feature conditions. However, for each of the two sets of stimuli we studied, there was one configuration that stood apart from the others in its set in that it yielded significantly faster response times, and in that conjunction conditions involving these particular stimuli tended to cluster with the feature conditions rather than with the other conjunction conditions. In addition to these major effects of particular targets, context effects also appeared in our results as effects of the various distractor sets used; certain of these context effects appear to be reversible. The effects of distractor sets on target search were studied in considerable detail. We have found interesting differences in visual processing between stimuli comprising separable features and those comprising configural features. We have also been able to characterize the effects we have found with configural-feature stimuli as being related to the specific feature structure of the target stimulus in the context of the specific feature structure of distractor stimuli. These findings have strong implications for the design of symbology that can enhance visual performance in the use of automated displays.

CVI Experience toolbox: Simulation of visual processing difficulties

2019 ◽  
Vol 37 (3) ◽  
pp. 248-257
Author(s):  
Florine Pilon-Kamsteeg ◽  
Marjoke J Dekker-Pap ◽  
Gerard C de Wit ◽  
Maria M van Genderen
Keyword(s):  
Information Processing ◽  
Visual Impairment ◽  
Visual Processing ◽  
Visual Information ◽  
Visual Information Processing ◽  
Previous Experience ◽  
Added Value ◽  
Slide Presentation ◽  
Cerebral Visual Impairment ◽  
Simulation Exercises

We designed a cerebral visual impairment (CVI)–experience toolbox containing simulation exercises to let professionals experience the complexity of visual information processing and to get an impression of what it means to have CVI. We measured the benefits of the CVI Experience toolbox by using questionnaires during three CVI seminars with professionals ( n = 69). These seminars started with a slide presentation on CVI followed by the CVI experience toolbox. We presented the professionals with the same survey on their knowledge of CVI at the start of the seminar, after the presentation, and after the toolbox. Professionals with more previous CVI experience started on average with a higher score. The final end score, however, did not seem to depend on previous experience. Furthermore, the added value of the experience toolset was quite independent of the added value of the presentation. The results indicate that both the presentationand the experience toolboxadd to the understanding of CVI.

Cortical Projection Topography of the Human Splenium: Hemispheric Asymmetry and Individual Differences

2010 ◽  
Vol 22 (8) ◽  
pp. 1662-1669 ◽  
Author(s):  
Mary Colvin Putnam ◽  
Megan S. Steven ◽  
Karl W. Doron ◽  
Adam C. Riggall ◽  
Michael S. Gazzaniga
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Hemispheric Asymmetry ◽  
Right Hemisphere ◽  
Diffusion Tensor ◽  
Cortical Projection ◽  
Interhemispheric Communication ◽  
Posterior Portion ◽  
Interhemispheric Connectivity ◽  
Visual Areas

The corpus callosum is the largest white matter pathway in the human brain. The most posterior portion, known as the splenium, is critical for interhemispheric communication between visual areas. The current study employed diffusion tensor imaging to delineate the complete cortical projection topography of the human splenium. Homotopic and heterotopic connections were revealed between the splenium and the posterior visual areas, including the occipital and the posterior parietal cortices. In nearly one third of participants, there were homotopic connections between the primary visual cortices, suggesting interindividual differences in splenial connectivity. There were also more instances of connections with the right hemisphere, indicating a hemispheric asymmetry in interhemispheric connectivity within the splenium. Combined, these findings demonstrate unique aspects of human interhemispheric connectivity and provide anatomical bases for hemispheric asymmetries in visual processing and a long-described hemispheric asymmetry in speed of interhemispheric communication for visual information.

scholarly journals REPRESENTATION OF 3-D VOLUMETRIC OBJECT FROM THE PANTOMIME EFFECT AND SHADING CUES IN HUMAN BRAIN

2007 ◽  
Vol 21 (08) ◽  
pp. 1307-1322
Author(s):  
QI ZHANG ◽  
KEN MOGI
Keyword(s):  
Human Brain ◽  
Visual Processing ◽  
Visual Information ◽  
Binocular Disparity ◽  
Object Perception ◽  
Human Beings ◽  
Brain Areas ◽  
Human Ability ◽  
Visual Areas ◽  
Visual Phenomenon

Human ability to process visual information of outside world is yet far ahead of man-made systems in accuracy and speed. In particular, human beings can perceive 3-D object from various cues, such as binocular disparity and monocular shading cues. Understanding of the mechanism of human visual processing will lead to a breakthrough in creating artificial visual systems. Here, we study the human 3-D volumetric object perception that is induced by a visual phenomenon named as the pantomime effect and by the monocular shading cues. We measured human brain activities using fMRI when the subjects were observing the visual stimuli. A coordinated system of brain areas, including those in the prefrontal and parietal cortex, in addition to the occipital visual areas was found to be involved in the volumetric object perception.

scholarly journals Serotonergic modulation of visual neurons in Drosophila melanogaster

2019 ◽  
Author(s):  
Maureen M Sampson ◽  
Katherine M Myers Gschweng ◽  
Ben J Hardcastle ◽  
Shivan L Bonanno ◽  
Tyler R Sizemore ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Information Processing ◽  
Visual Processing ◽  
Serotonin Receptors ◽  
Visual Information ◽  
Optic Lobe ◽  
Receptor Expression ◽  
Serotonergic Neurons ◽  
Visual Neurons ◽  
Kinetics Of

AbstractSensory systems rely on neuromodulators, such as serotonin, to provide flexibility for information processing in the face of a highly variable stimulus space. Serotonergic neurons broadly innervate the optic ganglia of Drosophila melanogaster, a widely used model for studying vision. The role for serotonergic signaling in the Drosophila optic lobe and the mechanisms by which serotonin regulates visual neurons remain unclear. Here we map the expression patterns of serotonin receptors in the visual system, focusing on a subset of cells with processes in the first optic ganglion, the lamina, and show that serotonin can modulate visual responses. Serotonin receptors are expressed in several types of columnar cells in the lamina including 5-HT2B in lamina monopolar cell L2, required for the initial steps of visual processing, and both 5-HT1A and 5-HT1B in T1 cells, whose function is unknown. Subcellular mapping with GFP-tagged 5-HT2B and 5-HT1A constructs indicates that these receptors localize to layer M2 of the medulla, proximal to serotonergic boutons, suggesting that the medulla is the primary site of serotonergic regulation for these neurons. Serotonin increases intracellular calcium in L2 terminals in layer M2 and alters the kinetics of visually induced calcium transients in L2 neurons following dark flashes. These effects were not observed in flies without a functional 5-HT2B, which displayed severe differences in the amplitude and kinetics of their calcium response to both dark and light flashes. While we did not detect serotonin receptor expression in L1 neurons, they also undergo serotonin-induced calcium changes, presumably via cell non-autonomous signaling pathways. We provide the first functional data showing a role for serotonergic neuromodulation of neurons required for initiating visual processing in Drosophila and establish a new platform for investigating the serotonergic neuromodulation of sensory networks.Author SummarySerotonergic neurons innervate the Drosophila melanogaster eye, but the function of serotonergic signaling is not known. We found that serotonin receptors are expressed in all neuropils of the optic lobe and identify specific neurons involved in visual information processing that express serotonin receptors. We then demonstrate that activation of these receptors can alter how visual information is processed. These are the first data suggesting a functional role for serotonergic signaling in Drosophila vision. This study contributes to the understanding of serotonin biology and modulation of sensory circuits.

scholarly journals A Unified Theory Of Early Visual Representations From Retina To Cortex Through Anatomically Constrained Deep CNNs

2019 ◽  
Author(s):  
Jack Lindsey ◽  
Samuel A. Ocko ◽  
Surya Ganguli ◽  
Stephane Deny
Keyword(s):  
Visual System ◽  
Visual Processing ◽  
Visual Information ◽  
Resource Constraints ◽  
Visual Representations ◽  
Direct Consequence ◽  
Visual Scene ◽  
Natural Scenes ◽  
Unified Theory ◽  
Cortical Networks

AbstractThe vertebrate visual system is hierarchically organized to process visual information in successive stages. Neural representations vary drastically across the first stages of visual processing: at the output of the retina, ganglion cell receptive fields (RFs) exhibit a clear antagonistic center-surround structure, whereas in the primary visual cortex (V1), typical RFs are sharply tuned to a precise orientation. There is currently no unified theory explaining these differences in representations across layers. Here, using a deep convolutional neural network trained on image recognition as a model of the visual system, we show that such differences in representation can emerge as a direct consequence of different neural resource constraints on the retinal and cortical networks, and for the first time we find a single model from which both geometries spontaneously emerge at the appropriate stages of visual processing. The key constraint is a reduced number of neurons at the retinal output, consistent with the anatomy of the optic nerve as a stringent bottleneck. Second, we find that, for simple downstream cortical networks, visual representations at the retinal output emerge as nonlinear and lossy feature detectors, whereas they emerge as linear and faithful encoders of the visual scene for more complex cortical networks. This result predicts that the retinas of small vertebrates (e.g. salamander, frog) should perform sophisticated nonlinear computations, extracting features directly relevant to behavior, whereas retinas of large animals such as primates should mostly encode the visual scene linearly and respond to a much broader range of stimuli. These predictions could reconcile the two seemingly incompatible views of the retina as either performing feature extraction or efficient coding of natural scenes, by suggesting that all vertebrates lie on a spectrum between these two objectives, depending on the degree of neural resources allocated to their visual system.

A Tale of Two Visual Systems: Invariant and Adaptive Visual Information Representations in the Primate Brain

2018 ◽  
Vol 4 (1) ◽  
pp. 311-336 ◽  
Author(s):  
Yaoda Xu
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Posterior Parietal Cortex ◽  
Visual Representations ◽  
Primate Brain ◽  
Visual Systems ◽  
Two Visual Systems ◽  
Adaptive Nature ◽  
And Behavior

Visual information processing contains two opposite needs. There is both a need to comprehend the richness of the visual world and a need to extract only pertinent visual information to guide thoughts and behavior at a given moment. I argue that these two aspects of visual processing are mediated by two complementary visual systems in the primate brain—specifically, the occipitotemporal cortex (OTC) and the posterior parietal cortex (PPC). The role of OTC in visual processing has been documented extensively by decades of neuroscience research. I review here recent evidence from human imaging and monkey neurophysiology studies to highlight the role of PPC in adaptive visual processing. I first document the diverse array of visual representations found in PPC. I then describe the adaptive nature of visual representation in PPC by contrasting visual processing in OTC and PPC and by showing that visual representations in PPC largely originate from OTC.

Dysfunction of Magnocellular/dorsal Processing Stream in Schizophrenia

2019 ◽  
Vol 15 (1) ◽  
pp. 26-36
Author(s):  
Sergio Chieffi
Keyword(s):  
Information Processing ◽  
Visual Processing ◽  
Visual Information ◽  
Visual Information Processing ◽  
Contour Detection ◽  
Backward Masking ◽  
Dorsal Pathway ◽  
Processing Stream ◽  
Early Processing ◽  
Processing Of Visual Information

Background: Patients with schizophrenia show not only cognitive, but also perceptual deficits. Perceptual deficits may affect different sensory modalities. Among these, the impairment of visual information processing is of particular relevance as demonstrated by the high incidence of visual disturbances. In recent years, the study of neurophysiological mechanisms that underlie visuo-perceptual, -spatial and -motor disorders in schizophrenia has increasingly attracted the interest of researchers. Objective: The study aims to review the existent literature on magnocellular/dorsal (occipitoparietal) visual processing stream impairment in schizophrenia. The impairment of relatively early stages of visual information processing was examined using experimental paradigms such as backward masking, contrast sensitivity, contour detection, and perceptual closure. The deficits of late processing stages were detected by examining visuo-spatial and -motor abilities. Results: Neurophysiological and behavioral studies support the existence of deficits in the processing of visual information along the magnocellular/dorsal pathway. These deficits appear to affect both early and late stages of visual information processing. Conclusion: The existence of disturbances in the early processing of visual information along the magnocellular/dorsal pathway is strongly supported by neurophysiological and behavioral observations. Early magnocellular dysfunction may provide a substrate for late dorsal processing impairment as well as higher-level cognition deficits.

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