scholarly journals Neuronal circuitry for stimulus selection in the visual system

2019 ◽  
Author(s):  
António M. Fernandes ◽  
Johannes Larsch ◽  
Joseph C. Donovan ◽  
Thomas O. Helmbrecht ◽  
Duncan Mearns ◽  
...  
Keyword(s):  
Visual Field ◽  
Visual Saliency ◽  
Saliency Map ◽  
Inhibitory Neurons ◽  
Stimulus Selection ◽  
Visual Responses ◽  
Classical Receptive Field ◽  
Single Cell Responses ◽  
Winner Take All ◽  
First Time

Visual objects naturally compete for the brain’s attention, and selecting just one of them for a behavioural response is often crucial for the animal’s survival1. The neural correlate of such stimulus prioritisation might take the form of a saliency map by which responses to one target are enhanced relative to distractors in other parts of the visual field2. Single-cell responses consistent with this type of computation have been observed in the tectum of primates, birds, turtles and lamprey2–7. However, the exact circuit implementation has remained unclear. Here we investigated the underlying neuronal mechanism presenting larval zebrafish with two simultaneous looming stimuli, each of which was able to trigger directed escapes on their own. Behaviour tracking revealed that the fish respond to these competing stimuli predominantly with a winner-take-all strategy. Using brain-wide functional recordings, we discovered neurons in the tectum whose responses to the target stimulus were non-linearly modulated by the saliency of the distractor. When the two stimuli were presented monocularly in different positions of the visual field, stimulus selection was already apparent in the activity of retinal ganglion cell axons, a likely consequence of antagonistic mechanisms operating outside the classical receptive field8,9. When the two stimuli were presented binocularly, i.e., on opposite sides of the fish, our analysis indicates that a loop involving excitatory and inhibitory neurons in the nucleus isthmi (NI) and the tectum weighed stimulus saliencies across hemispheres. Consistent with focal enhancement and global suppression, glutamatergic NI cells branch locally in the tectum, whereas GABAergic NI cells project broadly across both tectal hemispheres. Moreover, holographic optogenetic stimulation confirmed that glutamatergic NI neurons can modulate visual responses in the tectum. Together, our study shows, for the first time, context-dependent contributions of retinotectal and isthmotectal circuits to the computation of the visual saliency map, a prerequisite for stimulus-driven, bottom-up attention.

“Quelques misérables places à remplir”Locating Shaped Painting in Eighteenth-Century France

2017 ◽  
Vol 80 (4) ◽  
pp. 544-571
Author(s):  
David Pullins
Keyword(s):  
Eighteenth Century ◽  
Visual Field ◽  
Decorative Arts ◽  
Relationship Of ◽  
First Time ◽  
The Relationship

Abstract This article addresses in depth for the first time the irregularly shaped canvases known as tableaux chantournés (cut-out paintings) that were produced in vast numbers by leading academicians between the 1730s and 1750s and occupy a tenuous place between fine and applied or decorative arts. Through an examination of the term’s first uses in regard to painting and eighteenth-century critics’ responses to these works, tableaux chantournés are positioned as a means of rethinking the extraction of painting from a richer visual field and the relationship of this medium-specific agenda to the historiography of the rococo.

An Object-Based Image Reducing Approach

2014 ◽  
Vol 1044-1045 ◽  
pp. 1049-1052 ◽  
Author(s):  
Chin Chen Chang ◽  
I Ta Lee ◽  
Tsung Ta Ke ◽  
Wen Kai Tai
Keyword(s):  
Visual Saliency ◽  
Saliency Map ◽  
Input Image ◽  
Image Size ◽  
Target Image ◽  
Feature Maps ◽  
Object Based ◽  
Wide Range

Common methods for reducing image size include scaling and cropping. However, these two approaches have some quality problems for reduced images. In this paper, we propose an image reducing algorithm by separating the main objects and the background. First, we extract two feature maps, namely, an enhanced visual saliency map and an improved gradient map from an input image. After that, we integrate these two feature maps to an importance map. Finally, we generate the target image using the importance map. The proposed approach can obtain desired results for a wide range of images.

Video Objective Quality Evaluation System Based on the Visual Saliency Map

2013 ◽  
Vol 411-414 ◽  
pp. 1362-1367 ◽  
Author(s):  
Qing Lan Wei ◽  
Yuan Zhang
Keyword(s):  
Evaluation System ◽  
Quality Evaluation ◽  
Objective Assessment ◽  
Visual Saliency ◽  
Objective Evaluation ◽  
Subjective Assessment ◽  
Saliency Map ◽  
Assessment Scores ◽  
Objective Quality ◽  
Quality Evaluation System

This paper presents the thoughts about application of saliency map to the video objective quality evaluation system. It computes the SMSE and SPSNR values as the objective assessment scores according to the saliency map, and compares with conditional objective evaluation methods as PSNR and MSE. Experimental results demonstrate that this method can well fit the subjective assessment results.

Examination of the field of vision in pregnant women

1926 ◽  
Vol 22 (3) ◽  
pp. 333-335
Author(s):  
N. A. Popova
Keyword(s):  
Visual Field ◽  
Pregnant Women ◽  
International Congress ◽  
Field Of Vision ◽  
First Time

In a report to the International Congress of Ophthalmologists in America, in 1922, Finlay reported for the first time that when examining the eyes of one woman who was in the last month of pregnancy, he accidentally stumbled upon a sharp bilateral temporal narrowing of the visual field, and since there were no he could not detect the phenomenon of moments, he suggested that this narrowing of the field of vision depends on the hypertrophy of the cerebral appendage occurring during pregnancy.

Dynamic Properties of Recurrent Inhibition in Primary Visual Cortex: Contrast and Orientation Dependence of Contextual Effects

2000 ◽  
Vol 83 (2) ◽  
pp. 1019-1030 ◽  
Author(s):  
Valentin Dragoi ◽  
Mriganka Sur
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Primary Visual Cortex ◽  
Dynamic Properties ◽  
Orientation Dependence ◽  
Recurrent Inhibition ◽  
Inhibitory Neurons ◽  
Classical Receptive Field ◽  
Contextual Interactions ◽  
Receptive Field Center

A fundamental feature of neural circuitry in the primary visual cortex (V1) is the existence of recurrent excitatory connections between spiny neurons, recurrent inhibitory connections between smooth neurons, and local connections between excitatory and inhibitory neurons. We modeled the dynamic behavior of intermixed excitatory and inhibitory populations of cells in V1 that receive input from the classical receptive field (the receptive field center) through feedforward thalamocortical afferents, as well as input from outside the classical receptive field (the receptive field surround) via long-range intracortical connections. A counterintuitive result is that the response of oriented cells can be facilitated beyond optimal levels when the surround stimulus is cross-oriented with respect to the center and suppressed when the surround stimulus is iso-oriented. This effect is primarily due to changes in recurrent inhibition within a local circuit. Cross-oriented surround stimulation leads to a reduction of presynaptic inhibition and a supraoptimal response, whereas iso-oriented surround stimulation has the opposite effect. This mechanism is used to explain the orientation and contrast dependence of contextual interactions in primary visual cortex: responses to a center stimulus can be both strongly suppressed and supraoptimally facilitated as a function of surround orientation, and these effects diminish as stimulus contrast decreases.

scholarly journals Ship Detection in Panchromatic Optical Remote Sensing Images Based on Visual Saliency and Multi-Dimensional Feature Description

2020 ◽  
Vol 12 (1) ◽  
pp. 152 ◽  
Author(s):  
Ting Nie ◽  
Xiyu Han ◽  
Bin He ◽  
Xiansheng Li ◽  
Hongxing Liu ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Fourier Transform ◽  
Detection Method ◽  
Saliency Detection ◽  
Visual Saliency ◽  
Saliency Map ◽  
False Alarms ◽  
Optical Remote Sensing ◽  
Remote Sensing Images ◽  
Ship Detection

Ship detection in panchromatic optical remote sensing images is faced with two major challenges, locating candidate regions from complex backgrounds quickly and describing ships effectively to reduce false alarms. Here, a practical method was proposed to solve these issues. Firstly, we constructed a novel visual saliency detection method based on a hyper-complex Fourier transform of a quaternion to locate regions of interest (ROIs), which can improve the accuracy of the subsequent discrimination process for panchromatic images, compared with the phase spectrum quaternary Fourier transform (PQFT) method. In addition, the Gaussian filtering of different scales was performed on the transformed result to synthesize the best saliency map. An adaptive method based on GrabCut was then used for binary segmentation to extract candidate positions. With respect to the discrimination stage, a rotation-invariant modified local binary pattern (LBP) description was achieved by combining shape, texture, and moment invariant features to describe the ship targets more powerfully. Finally, the false alarms were eliminated through SVM training. The experimental results on panchromatic optical remote sensing images demonstrated that the presented saliency model under various indicators is superior, and the proposed ship detection method is accurate and fast with high robustness, based on detailed comparisons to existing efforts.

scholarly journals SALIENCY-GUIDED CHANGE DETECTION OF REMOTELY SENSED IMAGES USING RANDOM FOREST

2018 ◽  
Vol XLII-3 ◽  
pp. 341-348
Author(s):  
W. Feng ◽  
H. Sui ◽  
X. Chen
Keyword(s):  
Random Forest ◽  
Change Detection ◽  
Learning Algorithm ◽  
Saliency Detection ◽  
Principal Component ◽  
Visual Saliency ◽  
Saliency Map ◽  
Difference Image ◽  
Fcm Clustering ◽  
Optimal Segmentation

Studies based on object-based image analysis (OBIA) representing the paradigm shift in change detection (CD) have achieved remarkable progress in the last decade. Their aim has been developing more intelligent interpretation analysis methods in the future. The prediction effect and performance stability of random forest (RF), as a new kind of machine learning algorithm, are better than many single predictors and integrated forecasting method. In this paper, we present a novel CD approach for high-resolution remote sensing images, which incorporates visual saliency and RF. First, highly homogeneous and compact image super-pixels are generated using super-pixel segmentation, and the optimal segmentation result is obtained through image superimposition and principal component analysis (PCA). Second, saliency detection is used to guide the search of interest regions in the initial difference image obtained via the improved robust change vector analysis (RCVA) algorithm. The salient regions within the difference image that correspond to the binarized saliency map are extracted, and the regions are subject to the fuzzy <i>c</i>-means (FCM) clustering to obtain the pixel-level pre-classification result, which can be used as a prerequisite for superpixel-based analysis. Third, on the basis of the optimal segmentation and pixel-level pre-classification results, different super-pixel change possibilities are calculated. Furthermore, the changed and unchanged super-pixels that serve as the training samples are automatically selected. The spectral features and Gabor features of each super-pixel are extracted. Finally, superpixel-based CD is implemented by applying RF based on these samples. Experimental results on Ziyuan 3 (ZY3) multi-spectral images show that the proposed method outperforms the compared methods in the accuracy of CD, and also confirm the feasibility and effectiveness of the proposed approach.

scholarly journals Visual Responses of Mosquitoes Artificially Rendered Flightless

1947 ◽  
Vol 24 (1-2) ◽  
pp. 64-78 ◽  
Author(s):  
T. RAMACHANDRA RAO
Keyword(s):  
Visual Field ◽  
Negative Phototaxis ◽  
Visual Responses ◽  
Light Reduction ◽  
Vertical Band ◽  
Anopheles Maculipennis ◽  
Turning Response ◽  
Natural Movement ◽  
Black Band

Most females of Anopheles maculipennis and Culex molestus which had been rendered flightless by removal of wings or by sticking the wings together, tended to move towards a black vertical band when it was presented to them in an arena uniformly illuminated from below. The narrowest width of the band to which they could consistently respond was 0.5 cm. at a distance of 3.5 cm. corresponding to an angle of about 8°. When the edge of a wide black band was exactly in front of the mosquito or at about 45° to one side the movement towards it was consistent, but when the band was placed more and more posteriorly consistency of the responses progressively decreased. When offered simultaneously two black bands of equal or different widths the movement was to one of them. If a new band came into the view when the mosquito was already moving towards another, a turning response towards the new one took place very frequently. Unilaterally blinded specimens performed circus movements in uniform light. When a narrow black band came into the visual field of the functional eye there was an immediate turning response towards it. The negative phototaxis continued even at and after dusk at a time when flying mosquitoes were showing natural movement towards the evening light. Reduction of intensity of illumination and also the natural fading of the light at dusk both failed to bring about a reversal of response. For some undetermined reason mosquitoes rendered flightless always tend to move away from light. The mechanism of orientation seems to be in conformity with current ideas of negative phototropotaxis. No evidence of a photohorotaxis was secured.

scholarly journals Blotch Detection in Archive Films Based on Visual Saliency Map

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Yildiz Aydin ◽  
Bekir Dizdaroğlu
Keyword(s):  
Computational Complexity ◽  
Cultural Heritage ◽  
False Alarm ◽  
Detection Method ◽  
Visual Saliency ◽  
Saliency Map ◽  
Saliency Maps ◽  
Block Based ◽  
The Given ◽  
Blotch Detection

Degradations frequently occur in archive films that symbolize the historical and cultural heritage of a nation. In this study, the problem of detection blotches commonly encountered in archive films is handled. Here, a block-based blotch detection method is proposed based on a visual saliency map. The visual saliency map reveals prominent areas in an input frame and thus enables more accurate results in the blotch detection. A simple and effective visual saliency map method is taken into consideration in order to reduce computational complexity for the detection phase. After the visual saliency maps of the given frames are obtained, blotch regions are estimated by considered spatiotemporal patches—without the requirement for motion estimation—around the saliency pixels, which are subjected to a prethresholding process. Experimental results show that the proposed block-based blotch detection method provides a significant advantage with reducing false alarm rates over HOG feature (Yous and Serir, 2017), LBP feature (Yous and Serir, 2017), and regions-matching (Yous and Serir, 2016) methods presented in recent years.

Sign in / Sign up

Export Citation Format

Share Document