The role of early retinal lateral inhibition: More than maximizing luminance information

2000 ◽  
Vol 17 (1) ◽  
pp. 77-89 ◽  
Author(s):  
ROSARIO M. BALBOA ◽  
NORBERTO M. GRZYWACZ

Lateral inhibition is one of the first and most important stages of visual processing. There are at least four theories related to information theory in the literature for the role of early retinal lateral inhibition. They are based on the spatial redundancy in natural images and the advantage of removing this redundancy from the visual code. Here, we contrast these theories with data from the retina's outer plexiform layer. The horizontal cells' lateral-inhibition extent displays a bell-shape behavior as function of background luminance, whereas all the theories show a fall as luminance increases. It is remarkable that different theories predict the same luminance behavior, explaining “half” of the biological data. We argue that the main reason is how these theories deal with photon-absorption noise. At dim light levels, for which this noise is relatively large, large receptive fields would increase the signal-to-noise ratio through averaging. Unfortunately, such an increase at low luminance levels may smooth out basic visual information of natural images. To explain the biological behavior, we describe an alternate hypothesis, which proposes that the role of early visual lateral inhibition is to deal with noise without missing relevant clues from the visual world, most prominently, the occlusion boundaries between objects.

2009 ◽  
Vol 21 (3) ◽  
pp. 762-785 ◽  
Author(s):  
Yiu Fai Sit ◽  
Risto Miikkulainen

It has been more than 40 years since the first studies of the secondary visual cortex (V2) were published. However, no concrete hypothesis on how the receptive field of V2 neurons supports general shape processing has been proposed to date. Using a computational model that follows the principle of self-organization, we advance two hypotheses in this letter: (1) typical V2 orientation-selective receptive field contains a primary orientation and a secondary orientation component, forming a corner, a junction, or a cross; and (2) V2 columns with the same primary orientation form contiguous domains, divided into subdomains that prefer different secondary orientations. The first hypothesis is consistent with existing experimental evidence, and both hypotheses can be tested with current techniques in animals. In this manner, computational modeling can be used to provide verifiable predictions that eventually allow us to understand the role of V2 in visual processing.


eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Jen-Chun Hsiang ◽  
Keith P Johnson ◽  
Linda Madisen ◽  
Hongkui Zeng ◽  
Daniel Kerschensteiner

Neurons receive synaptic inputs on extensive neurite arbors. How information is organized across arbors and how local processing in neurites contributes to circuit function is mostly unknown. Here, we used two-photon Ca2+ imaging to study visual processing in VGluT3-expressing amacrine cells (VG3-ACs) in the mouse retina. Contrast preferences (ON vs. OFF) varied across VG3-AC arbors depending on the laminar position of neurites, with ON responses preferring larger stimuli than OFF responses. Although arbors of neighboring cells overlap extensively, imaging population activity revealed continuous topographic maps of visual space in the VG3-AC plexus. All VG3-AC neurites responded strongly to object motion, but remained silent during global image motion. Thus, VG3-AC arbors limit vertical and lateral integration of contrast and location information, respectively. We propose that this local processing enables the dense VG3-AC plexus to contribute precise object motion signals to diverse targets without distorting target-specific contrast preferences and spatial receptive fields.


2017 ◽  
Author(s):  
Jen-Chun Hsiang ◽  
Keith Johnson ◽  
Linda Madisen ◽  
Hongkui Zeng ◽  
Daniel Kerschensteiner

AbstractSynaptic inputs to neurons are distributed across extensive neurite arborizations. To what extent arbors process inputs locally or integrate them globally is, for most neurons, unknown. This question is particularly relevant for amacrine cells, a diverse class of retinal interneurons, which receive input and provide output through the same neurites. Here, we used two-photon Ca2+ imaging to analyze visual processing in VGluT3-expressing amacrine cells (VG3-ACs), an important component of object motion sensitive circuits in the retina. VG3-AC neurites differed in their preferred stimulus contrast (ON vs. OFF); and ON and OFF responses varied in transience and preferred stimulus size. Contrast preference changed predictably with the laminar position of neurites in the inner plexiform layer. Yet, neurites at all depths were strongly activated by local but not by global image motion. Thus, VG3-AC neurites process visual information locally, exhibiting diverse responses to contrast steps, but uniform object motion selectivity.


2020 ◽  
Author(s):  
Karola Schlegelmilch ◽  
Annie E. Wertz

Visual processing of a natural environment occurs quickly and effortlessly. Yet, little is known about how young children are able to visually categorize naturalistic structures, since their perceptual abilities are still developing. We addressed this question by asking 76 children (age: 4.1-6.1 years) and 72 adults (age: 18-50 years) to first sort cards with greyscale images depicting vegetation, manmade artifacts, and non-living natural elements (e.g., stones) into groups according to visual similarity. Then, they were asked to choose the images' superordinate categories. We analyzed the relevance of different visual properties to the decisions of the participant groups. Children were very well able to interpret complex visual structures. However, children relied on fewer visual properties and, in general, were less likely to include properties which afforded the analysis of detailed visual information in their categorization decisions than adults, suggesting that immaturities of the still-developing visual system affected categorization. Moreover, when sorting according to visual similarity, both groups attended to the images' assumed superordinate categories—in particular to vegetation—in addition to visual properties. Children had a higher relative sensitivity for vegetation than adults did in the classification task when controlling for overall performance differences. Taken together, these findings add to the sparse literature on the role of developing perceptual abilities in processing naturalistic visual input.


2017 ◽  
Vol 34 ◽  
Author(s):  
ELIZABETH Y. LITVINA ◽  
CHINFEI CHEN

AbstractThe thalamocortical (TC) relay neuron of the dorsoLateral Geniculate Nucleus (dLGN) has borne its imprecise label for many decades in spite of strong evidence that its role in visual processing transcends the implied simplicity of the term “relay”. The retinogeniculate synapse is the site of communication between a retinal ganglion cell and a TC neuron of the dLGN. Activation of retinal fibers in the optic tract causes reliable, rapid, and robust postsynaptic potentials that drive postsynaptics spikes in a TC neuron. Cortical and subcortical modulatory systems have been known for decades to regulate retinogeniculate transmission. The dynamic properties that the retinogeniculate synapse itself exhibits during and after developmental refinement further enrich the role of the dLGN in the transmission of the retinal signal. Here we consider the structural and functional substrates for retinogeniculate synaptic transmission and plasticity, and reflect on how the complexity of the retinogeniculate synapse imparts a novel dynamic and influential capacity to subcortical processing of visual information.


Author(s):  
Brian Rogers

‘The physiology and anatomy of the visual system’ describes what we have learned from neurophysiology and anatomy over the past eighty years and what this tells us about the meaning of the circuits involved in visual information processing. It explains how psychologists and physiologists use the terms ‘mechanism’ and ‘process’. For physiologists, a mechanism is linked to the actions of individual neurons, neural pathways, and the ways in which the neurons are connected up. For psychologists, the term is typically used to describe the processes the neural circuits may carry out. The human retina is described with explanations of lateral inhibition, receptive fields, and feature detectors as well as the visual cortex and different visual pathways.


Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Ruchi Kothari ◽  
Pradeep Bokariya ◽  
Smita Singh ◽  
Ramji Singh

Visual information is fundamental to how we appreciate our environment and interact with others. The visual evoked potential (VEP) is among those evoked potentials that are the bioelectric signals generated in the striate and extrastriate cortex when the retina is stimulated with light which can be recorded from the scalp electrodes. In the current paper, we provide an overview of the various modalities, techniques, and methodologies which have been employed for visual evoked potentials over the years. In the first part of the paper, we cast a cursory glance on the historical aspect of evoked potentials. Then the growing clinical significance and advantages of VEPs in clinical disorders have been briefly described, followed by the discussion on the earlier and currently available methods for VEPs based on the studies in the past and recent times. Next, we mention the standards and protocols laid down by the authorized agencies. We then summarize the recently developed techniques for VEP. In the concluding section, we lay down prospective research directives related to fundamental and applied aspects of VEPs as well as offering perspectives for further research to stimulate inquiry into the role of visual evoked potentials in visual processing impairment related disorders.


2018 ◽  
Vol 4 (1) ◽  
pp. 311-336 ◽  
Author(s):  
Yaoda Xu

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.


2010 ◽  
Vol 22 (7) ◽  
pp. 1812-1836 ◽  
Author(s):  
Laurent U. Perrinet

Neurons in the input layer of primary visual cortex in primates develop edge-like receptive fields. One approach to understanding the emergence of this response is to state that neural activity has to efficiently represent sensory data with respect to the statistics of natural scenes. Furthermore, it is believed that such an efficient coding is achieved using a competition across neurons so as to generate a sparse representation, that is, where a relatively small number of neurons are simultaneously active. Indeed, different models of sparse coding, coupled with Hebbian learning and homeostasis, have been proposed that successfully match the observed emergent response. However, the specific role of homeostasis in learning such sparse representations is still largely unknown. By quantitatively assessing the efficiency of the neural representation during learning, we derive a cooperative homeostasis mechanism that optimally tunes the competition between neurons within the sparse coding algorithm. We apply this homeostasis while learning small patches taken from natural images and compare its efficiency with state-of-the-art algorithms. Results show that while different sparse coding algorithms give similar coding results, the homeostasis provides an optimal balance for the representation of natural images within the population of neurons. Competition in sparse coding is optimized when it is fair. By contributing to optimizing statistical competition across neurons, homeostasis is crucial in providing a more efficient solution to the emergence of independent components.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eugenio Piasini ◽  
Liviu Soltuzu ◽  
Paolo Muratore ◽  
Riccardo Caramellino ◽  
Kasper Vinken ◽  
...  

AbstractCortical representations of brief, static stimuli become more invariant to identity-preserving transformations along the ventral stream. Likewise, increased invariance along the visual hierarchy should imply greater temporal persistence of temporally structured dynamic stimuli, possibly complemented by temporal broadening of neuronal receptive fields. However, such stimuli could engage adaptive and predictive processes, whose impact on neural coding dynamics is unknown. By probing the rat analog of the ventral stream with movies, we uncovered a hierarchy of temporal scales, with deeper areas encoding visual information more persistently. Furthermore, the impact of intrinsic dynamics on the stability of stimulus representations grew gradually along the hierarchy. A database of recordings from mouse showed similar trends, additionally revealing dependencies on the behavioral state. Overall, these findings show that visual representations become progressively more stable along rodent visual processing hierarchies, with an important contribution provided by intrinsic processing.


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