On nonlinearity in neural encoding models applied to the primary visual cortex

Within the regression framework, we show how different levels of nonlinearity influence the instantaneous firing rate prediction of single neurons. Nonlinearity can be achieved in several ways. In particular, we can enrich the predictor set with basis expansions of the input variables (enlarging the number of inputs) or train a simple but different model for each area of the data domain. Spline-based models are popular within the first category. Kernel smoothing methods fall into the second category. Whereas the first choice is useful for globally characterizing complex functions, the second is very handy for temporal data and is able to include inner-state subject variations. Also, interactions among stimuli are considered. We compare state-of-the-art firing rate prediction methods with some more sophisticated spline-based nonlinear methods: multivariate adaptive regression splines and sparse additive models. We also study the impact of kernel smoothing. Finally, we explore the combination of various local models in an incremental learning procedure. Our goal is to demonstrate that appropriate nonlinearity treatment can greatly improve the results. We test our hypothesis on both synthetic data and real neuronal recordings in cat primary visual cortex, giving a plausible explanation of the results from a biological perspective.

Crop row detection in maize fields inspired on the human visual perception

This paper proposes a new method, oriented to image real-time processing, for identifying crop rows in maize fields in the images. The vision system is designed to be installed onboard a mobile agricultural vehicle, that is, submitted to gyros, vibrations, and undesired movements. The images are captured under image perspective, being affected by the above undesired effects. The image processing consists of two main processes: image segmentation and crop row detection. The first one applies a threshold to separate green plants or pixels (crops and weeds) from the rest (soil, stones, and others). It is based on a fuzzy clustering process, which allows obtaining the threshold to be applied during the normal operation process. The crop row detection applies a method based on image perspective projection that searches for maximum accumulation of segmented green pixels along straight alignments. They determine the expected crop lines in the images. The method is robust enough to work under the above-mentioned undesired effects. It is favorably compared against the well-tested Hough transformation for line detection.

On-road visual vehicle tracking using Markov chain Monte Carlo with metropolis sampling

In this study, a method for vehicle tracking through video analysis based on Markov chain Monte Carlo (MCMC) particle filtering with metropolis sampling is proposed. The method handles multiple targets with low computational requirements and is, therefore, ideally suited for advanced-driver assistance systems that involve real-time operation. The method exploits the removed perspective domain given by inverse perspective mapping (IPM) to define a fast and efficient likelihood model. Additionally, the method encompasses an interaction model using Markov Random Fields (MRF) that allows treatment of dependencies between the motions of targets. The proposed method is tested in highway sequences and compared to state-of-the-art methods for vehicle tracking, i.e., independent target tracking with Kalman filtering (KF) and joint tracking with particle filtering. The results showed fewer tracking failures using the proposed method.

O endossamento de celebridades na propaganda sob a ótica do Neuromarketing: um estudo sobre a influência de uma celebridade no processo de atenção visual

O presente estudo buscou entender a influência da utilização da celebridade Gisele Bundchen em anúncios de propaganda no comportamento do consumidor por meio de uma das técnicas de Neuromarketing: o eye tracking. Sendo assim, esta pesquisa objetivou analisar se é realmente importante a presença da celebridade em propagandas de anúncio impresso analisada sob o ponto de vista do Neuromarketing por meio da análise da atenção visual ao estímulo \'celebridade\'. Para a verificação dos objetivos, das hipóteses e da proposição advindas destes objetivos, foi empregada uma metodologia em que se buscou avaliar a atenção visual dos consumidores acerca do estímulo \'celebridade\' em relação aos demais estímulos presentes nos anúncios impressos como a logomarca, nome ou símbolo que representa a marca; o produto; e outras pessoas não famosas. Essa avaliação foi realizada por meio da técnica de Neuromarketing que utiliza o equipamento de eye tracking. Assim, os participantes foram divididos em três grupos (um que avaliou os anúncios das seis marcas com a celebridade; o outro que avaliou os anúncios destas mesmas marcas com a presença de pessoas não famosas e um último grupo que avaliou os anúncios das marcas sem a presença de pessoas). No final do foi aplicado um questionário para confirmação de alguns dados e para análise em relação à lembrança da marca. Os resultados, no geral, demonstraram que, de alguma forma, os participantes prestaram atenção na celebridade considerada na pesquisa (o que foi evidenciado, principalmente, pelos mapas de calor apresentados). Quando as celebridades foram comparadas às pessoas não famosas, em alguns casos (com a confirmação de algumas hipóteses), foi evidenciada a importância da presença da celebridade; porém, em outros casos, houve mais destaque para a presença da pessoa não famosa. Na pesquisa ficou evidente, também, que a presença de pessoas (sendo elas celebridade ou não) pode atrapalhar no processo de atenção para a marca e o produto e que, quando não se utilizou pessoas, houve mais atenção dos participantes para estes outros estímulos.

3D information visualisation: An historical perspective

The use of 3D visualisation of digital information is a recent phenomenon. It relies on users understanding 3D perspectival spaces. Questions about the universal access of such spaces has been debated since its inception in the European Renaissance. Perspective has since become a strong cultural influence in Western visual communication. Perspective imaging assists the process of experimenting by the sketching or modelling of ideas. In particular, the recent 3D modelling of an essentially non-dimensional Cyber-space raises questions of how we think about information in general. While alternate methods clearly exist they are rarely explored within the 3D paradigm (such as Chinese isometry). This paper seeks to generate further discussion on the historical background of perspective and its role in underpinning this emergent field. © 2005 IEEE.

A visual interactive modelling system as a learning tool

This paper presents a case study of the use of a visual interactive modelling system to investigate issues involved in the management of a hospital ward. Visual Interactive Modelling systems are seen to offer the learner the opportunity to explore operational management issues from a varied perspective and to provide an interactive system in which the learner receives feedback on the consequences of their actions. However to maximise the potential learning experience for a student requires the recognition that they require task structure which helps them to understand the concepts involved. These factors can be incorporated into the visual interactive model by providing an interface customised to guide the student through the experimentation. Recent developments of VIM systems in terms of their connectivity with the programming language Visual Basic facilitates this customisation.

Sanctioning pregnancy:a psychological perspective on the paradoxes and culture of research

Pregnancy provides a very public, visual confirmation of femininity. It is a time of rapid physical and psychological adjustment for women and is surrounded by stereotyping, taboos and social expectations. This book seeks to examine these popular attitudes towards pregnancy and to consider how they influence women’s experiences of being pregnant. Sanctioning Pregnancy offers a unique critique of sociocultural constructions of pregnancy and the ways in which it is represented in contemporary culture, and examines the common myths which exist about diet, exercise and work in pregnancy, alongside notions of risk and media portrayals of pregnant women. Topics covered include: •Do pregnant women change their diet and why? •Is memory really impaired in pregnancy? •How risky behaviour is defined from exercise to employment •The biomedical domination of pregnancy research. Different theoretical standpoints are critically examined, including a medico-scientific model, feminist perspectives and bio-psychosocial and psychodynamic approaches. Table of Contents: Introduction. Cognition and Cognitive Dysfunction. Working and Employment. Dietary Change and Eating. Exercise and Activity. Pregnancy and Risk. Pregnancy Under Surveillance. Concluding Remarks. References/Bibliography. Index.

A penny for your thoughts! Patterns of fMRI activity reveal the content and the spatial topography of visual mental images

Visual mental imagery is a complex process that may be influenced by the content of mental images. Neuropsychological evidence from patients with hemineglect suggests that in the imagery domain environments and objects may be represented separately and may be selectively affected by brain lesions. In the present study, we used functional magnetic resonance imaging (fMRI) to assess the possibility of neural segregation among mental images depicting parts of an object, of an environment (imagined from a first-person perspective), and of a geographical map, using both a mass univariate and a multivariate approach. Data show that different brain areas are involved in different types of mental images. Imagining an environment relies mainly on regions known to be involved in navigational skills, such as the retrosplenial complex and parahippocampal gyrus, whereas imagining a geographical map mainly requires activation of the left angular gyrus, known to be involved in the representation of categorical relations. Imagining a familiar object mainly requires activation of parietal areas involved in visual space analysis in both the imagery and the perceptual domain. We also found that the pattern of activity in most of these areas specifically codes for the spatial arrangement of the parts of the mental image. Our results clearly demonstrate a functional neural segregation for different contents of mental images and suggest that visuospatial information is coded by different patterns of activity in brain areas involved in visual mental imagery. Hum Brain Mapp 36:945-958, 2015.

Desenho de deficiência visual: uma experiência no ensino de artes visuais na perspectiva da educação inclusiva

Over the past 30 years, Art Education in interface with disabilities has been a subject of increasing interest in research in academia, especially with regard to Special Education, but still has some shortages in terms of socialization studies to discuss this type of teaching from the perspective of inclusive education. In this scenario, this paper presents an analysis from the field of teaching Visual Arts in the context of school inclusion, with emphasis on teaching drawing to the visually impaired. The conducted literature indicates a number of authors who discuss teaching drawing to people with visual disabilities, who are dedicated primarily to the Special Education context. In this sense, the shortage of research that discuss this teaching from the perspective of inclusive education, this research aimed at the inclusive approach to teaching drawing in the school context. Thus, the aim of this study was to develop a proposal for a pedagogical intervention in Visual Arts, with reference to drawing and its construction process, with the participation of seeing and unseeing students. Therefore, the methodological approach, which was qualitative, was the intervention research, in the light of the Bakhtinian principles of dialogism and otherness, with exploratory study characteristics. The locus of the research was the State School Admiral Newton Braga Faria, which is located in Alecrim, on the East Zone of Natal / RN and is near the Institute for Education and Rehabilitation of the Blind - IERC / RN. The class chosen for intervention was the 7th grade “C” afternoon shift, which had children aged 12 to 16, with 27 students enrolled, three students with disabilities: 02 blind girls and 01 deafblind boy with light hearing and visual loss. As interlocutors of the research, we could also count on the Art teacher who served as a collaborator, as well as teacher in the school’s Multifunction Resource Room. The instruments and research procedures were observation, semi-structured interview, field diary and the photo / video recording. In the development of research, we conducted 10 workshops with multisensory teaching sequences, articulating the physical, tactile and graphical expressions as intrinsic to the reading and production of drawing for both seeing and unseeing students. The process and data built on research allowed for a reflection on cultural experiences with drawing in the school context and on the interactions between seeing and unseeing students in the production and analysis of tactile-visual drawings. They also point out the construction of a teaching approach to drawing, in the context of the common class, from educational workshops that enable artistic and aesthetic interactions from the perspective of school inclusiveness. Thus, we argued that the mobilization of the tactile, physical and graphical expressions can be adopted in a multisensory approach that enables a pedagogical focus that involves all students and is not restricted to the presence of students with visual impairment.

Realism and national identity in 'Y Tu Mamá También': an audience perspective

When referring to cinema and its emancipatory potential, realism, like Plato’s pharmakon, has signified both illness and cure, poison and medicine. On the one hand, realism is regarded as the main feature of so-called classical cinema, inherently conservative and thoroughly ideological, its main raison d’être being to reify and make a particular version of the status quo believable and to pass it out as ‘reality’ (Burch, 1990; MacCabe, 1974). On the other, realism has also been interpreted as a quest for truth and social justice, as in the positivist ethos that informs documentary (Zavattini, 1953). Even in the latter sense, however, the extent to which realism has served colonizing ends when used to investigate the ‘truth’ of the Other has also been noted, rendering the form profoundly suspicious (Chow, 2007, p. 150). For realism has been a Western form of representation, one that can be traced back to the invention of perspective in painting and that peaked with the secular worldview brought about by the Enlightenment. And like realism, the nation state too is a product of the Enlightenment, nationalism being, as it were, a secular replacement for the religious - that is enchanted or fantastic - worldview. In this way, realism, cinema and nation are inextricably linked, and equally strained under the current decline of the Enlightenment paradigm. This chapter looks at Y tu Mamá También by Alfonso Cuarón (2001), a highly successful road movie with documentary features, to explore the ways in which realism, cinema and nation interact with each other in the present conditions of ‘globalization’ as experienced in Mexico. The chapter compares and contrasts various interpretations of the role of realism in this film put forward by critics and scholars and other discourses about it circulating in the media with actual ways of audience engagement with it.

Epistemología del pensamiento visual contemporáneo desde el imaginario transdisciplinario

El pensamiento visual contemporáneo trae consigo un campo nuevo deconocimiento. Los llamados estudios visuales implican nuevos problemas, que se caracterizan, a su vez, por niveles de complejidad inéditos y requerimientos transdisciplinarios de abordaje. Este estudio propone un análisis epistemológico a partir del problema de la construcción de la realidad, en su relación con el imaginario y el régimen escópico. En este sentido, se insiste en la apertura al estudio de la visualidad –sobre todo– desde una perspectiva compleja y transdisciplinaria.

Integrated visual perception architecture for robotic clothes perception and manipulation

This thesis proposes a generic visual perception architecture for robotic clothes perception and manipulation. This proposed architecture is fully integrated with a stereo vision system and a dual-arm robot and is able to perform a number of autonomous laundering tasks. Clothes perception and manipulation is a novel research topic in robotics and has experienced rapid development in recent years. Compared to the task of perceiving and manipulating rigid objects, clothes perception and manipulation poses a greater challenge. This can be attributed to two reasons: firstly, deformable clothing requires precise (high-acuity) visual perception and dexterous manipulation; secondly, as clothing approximates a non-rigid 2-manifold in 3-space, that can adopt a quasi-infinite configuration space, the potential variability in the appearance of clothing items makes them difficult to understand, identify uniquely, and interact with by machine. From an applications perspective, and as part of EU CloPeMa project, the integrated visual perception architecture refines a pre-existing clothing manipulation pipeline by completing pre-wash clothes (category) sorting (using single-shot or interactive perception for garment categorisation and manipulation) and post-wash dual-arm flattening. To the best of the author’s knowledge, as investigated in this thesis, the autonomous clothing perception and manipulation solutions presented here were first proposed and reported by the author. All of the reported robot demonstrations in this work follow a perception-manipulation method- ology where visual and tactile feedback (in the form of surface wrinkledness captured by the high accuracy depth sensor i.e. CloPeMa stereo head or the predictive confidence modelled by Gaussian Processing) serve as the halting criteria in the flattening and sorting tasks, respectively. From scientific perspective, the proposed visual perception architecture addresses the above challenges by parsing and grouping 3D clothing configurations hierarchically from low-level curvatures, through mid-level surface shape representations (providing topological descriptions and 3D texture representations), to high-level semantic structures and statistical descriptions. A range of visual features such as Shape Index, Surface Topologies Analysis and Local Binary Patterns have been adapted within this work to parse clothing surfaces and textures and several novel features have been devised, including B-Spline Patches with Locality-Constrained Linear coding, and Topology Spatial Distance to describe and quantify generic landmarks (wrinkles and folds). The essence of this proposed architecture comprises 3D generic surface parsing and interpretation, which is critical to underpinning a number of laundering tasks and has the potential to be extended to other rigid and non-rigid object perception and manipulation tasks. The experimental results presented in this thesis demonstrate that: firstly, the proposed grasp- ing approach achieves on-average 84.7% accuracy; secondly, the proposed flattening approach is able to flatten towels, t-shirts and pants (shorts) within 9 iterations on-average; thirdly, the proposed clothes recognition pipeline can recognise clothes categories from highly wrinkled configurations and advances the state-of-the-art by 36% in terms of classification accuracy, achieving an 83.2% true-positive classification rate when discriminating between five categories of clothes; finally the Gaussian Process based interactive perception approach exhibits a substantial improvement over single-shot perception. Accordingly, this thesis has advanced the state-of-the-art of robot clothes perception and manipulation.

ViDRILO: The Visual and Depth Robot Indoor Localization with Objects information dataset

In this article we describe a semantic localization dataset for indoor environments named ViDRILO. The dataset provides five sequences of frames acquired with a mobile robot in two similar office buildings under different lighting conditions. Each frame consists of a point cloud representation of the scene and a perspective image. The frames in the dataset are annotated with the semantic category of the scene, but also with the presence or absence of a list of predefined objects appearing in the scene. In addition to the frames and annotations, the dataset is distributed with a set of tools for its use in both place classification and object recognition tasks. The large number of labeled frames in conjunction with the annotation scheme make this dataset different from existing ones. The ViDRILO dataset is released for use as a benchmark for different problems such as multimodal place classification and object recognition, 3D reconstruction or point cloud data compression.

Advancing Bag-of-visual-words Representations For Lesion Classification In Retinal Images.

Diabetic Retinopathy (DR) is a complication of diabetes that can lead to blindness if not readily discovered. Automated screening algorithms have the potential to improve identification of patients who need further medical attention. However, the identification of lesions must be accurate to be useful for clinical application. The bag-of-visual-words (BoVW) algorithm employs a maximum-margin classifier in a flexible framework that is able to detect the most common DR-related lesions such as microaneurysms, cotton-wool spots and hard exudates. BoVW allows to bypass the need for pre- and post-processing of the retinographic images, as well as the need of specific ad hoc techniques for identification of each type of lesion. An extensive evaluation of the BoVW model, using three large retinograph datasets (DR1, DR2 and Messidor) with different resolution and collected by different healthcare personnel, was performed. The results demonstrate that the BoVW classification approach can identify different lesions within an image without having to utilize different algorithms for each lesion reducing processing time and providing a more flexible diagnostic system. Our BoVW scheme is based on sparse low-level feature detection with a Speeded-Up Robust Features (SURF) local descriptor, and mid-level features based on semi-soft coding with max pooling. The best BoVW representation for retinal image classification was an area under the receiver operating characteristic curve (AUC-ROC) of 97.8% (exudates) and 93.5% (red lesions), applying a cross-dataset validation protocol. To assess the accuracy for detecting cases that require referral within one year, the sparse extraction technique associated with semi-soft coding and max pooling obtained an AUC of 94.2 ± 2.0%, outperforming current methods. Those results indicate that, for retinal image classification tasks in clinical practice, BoVW is equal and, in some instances, surpasses results obtained using dense detection (widely believed to be the best choice in many vision problems) for the low-level descriptors.

Visual Navigation In The Neotropical Ant Odontomachus Hastatus (formicidae, Ponerinae), A Predominantly Nocturnal, Canopy-dwelling Predator Of The Atlantic Rainforest.

The arboreal ant Odontomachus hastatus nests among roots of epiphytic bromeliads in the sandy forest at Cardoso Island (Brazil). Crepuscular and nocturnal foragers travel up to 8m to search for arthropod prey in the canopy, where silhouettes of leaves and branches potentially provide directional information. We investigated the relevance of visual cues (canopy, horizon patterns) during navigation in O. hastatus. Laboratory experiments using a captive ant colony and a round foraging arena revealed that an artificial canopy pattern above the ants and horizon visual marks are effective orientation cues for homing O. hastatus. On the other hand, foragers that were only given a tridimensional landmark (cylinder) or chemical marks were unable to home correctly. Navigation by visual cues in O. hastatus is in accordance with other diurnal arboreal ants. Nocturnal luminosity (moon, stars) is apparently sufficient to produce contrasting silhouettes from the canopy and surrounding vegetation, thus providing orientation cues. Contrary to the plain floor of the round arena, chemical cues may be important for marking bifurcated arboreal routes. This experimental demonstration of the use of visual cues by a predominantly nocturnal arboreal ant provides important information for comparative studies on the evolution of spatial orientation behavior in ants. This article is part of a Special Issue entitled: Neotropical Behaviour.