Visual avoidance in phobia: particularities in neural activity, autonomic responding, and cognitive risk evaluations.

We investigated the neural mechanisms and the autonomic and cognitive responses associated with visual avoidance behavior in spider phobia. Spider phobic and control participants imagined visiting different forest locations with the possibility of encountering spiders, snakes, or birds (neutral reference category). In each experimental trial, participants saw a picture of a forest location followed by a picture of a spider, snake, or bird, and then rated their personal risk of encountering these animals in this context, as well as their fear. The greater the visual avoidance of spiders that a phobic participant demonstrated (as measured by eye tracking), the higher were her autonomic arousal and neural activity in the amygdala, orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), and precuneus at picture onset. Visual avoidance of spiders in phobics also went hand in hand with subsequently reduced cognitive risk of encounters. Control participants, in contrast, displayed a positive relationship between gaze duration toward spiders, on the one hand, and autonomic responding, as well as OFC, ACC, and precuneus activity, on the other hand. In addition, they showed reduced encounter risk estimates when they looked longer at the animal pictures. Our data are consistent with the idea that one reason for phobics to avoid phobic information may be grounded in heightened activity in the fear circuit, which signals potential threat. Because of the absence of alternative efficient regulation strategies, visual avoidance may then function to down-regulate cognitive risk evaluations for threatening information about the phobic stimuli. Control participants, in contrast, may be characterized by a different coping style, whereby paying visual attention to potentially threatening information may help them to actively down-regulate cognitive evaluations of risk.

The Quiet Eye and Information Processing: Facilitation of Stimulus Identification and Response Selection

Background: A prerequisite for high performance in motor tasks is the acquisition of egocentric sensory information that must be translated into motor actions. A phenomenon that supports this process is the Quiet Eye (QE) defined as long final fixation before movement initiation. It is assumed that the QE facilitates information processing, particularly regarding movement parameterization. Aims: The question remains whether this facilitation also holds for the information-processing stage of response selection and – related to perception crucial – stage of stimulus identification. Method: In two experiments with sport science students, performance-enhancing effects of experimentally manipulated QE durations were tested as a function of target position predictability and target visibility, thereby selectively manipulating response selection and stimulus identification demands, respectively. Results: The results support the hypothesis of facilitated information processing through long QE durations since in both experiments performance-enhancing effects of long QE durations were found under increased processing demands only. In Experiment 1, QE duration affected performance only if the target position was not predictable and positional information had to be processed over the QE period. In Experiment 2, in a full vs. no target visibility comparison with saccades to the upcoming target position induced by flicker cues, the functionality of a long QE duration depended on the visual stimulus identification period as soon as the interval falls below a certain threshold. Conclusions: The results corroborate earlier findings that QE efficiency depends on demands put on the visuomotor system, thereby furthering the assumption that the phenomenon supports the processes of sensorimotor integration.

Visual Hallucinations in Eye Disease and Lewy Body Disease

Objective: Visual hallucinations (VH) most commonly occur in eye disease (ED), Parkinson’s disease (PD), and Lewy body dementia (LBD). The phenomenology of VH is likely to carry important information about the brain areas within the visual system generating them. Methods: Data from five controlled cross-sectional VH studies (164 controls, 135 ED, 156 PD, 79 (PDD 48 + DLB 31) LBD) were combined and analysed. The prevalence, phenomenology, frequency, duration, and contents of VH were compared across diseases and gender. Results: Simple VH were most common in ED patients (ED 65% vs. LBD 22% vs. PD 9%, Chi-square [χ2] test: χ2=31.43, df=2, p<0.001), whilst complex VH were more common in LBD (LBD 76% vs. ED 38%, vs PD 28%, Chi-square test: χ2=96.80, df=2, p<0.001). The phenomenology of complex VH was different across diseases and gender. ED patients reported more “flowers” (ED 21% vs. LBD 6% vs. PD 0%, Chi-square test: χ2=10.04, df=2, p=0.005) and “body parts” (ED 40% vs. LBD 17% vs. PD 13%, Chi-square test: χ2=11.14, df=2, p=0.004); in contrast LBD patients reported “people” (LBD 85% vs. ED 67% vs. PD 63%, Chi-square test: χ2=6.20, df=2, p=0.045) and “animals/insects” (LBD 50% vs. PD 42% vs. ED 21%, Chi-square test: χ2=9.76, df=2, p=0.008). Males reported more “machines” (13 % vs. 2%, Chi-square test: χ2=6.94, df=1, p=0.008), whilst females reported more “family members/children” (48% vs. 29%, Chi-square test: χ2=5.10, df=1, p=0.024). Conclusions: The phenomenology of VH is likely related to disease specific dysfunctions within the visual system and to past, personal experiences.

Dynamic population coding in primary visual cortex

More than a century ago Ramon y Cajal pioneered the description of neural circuits. Currently, new techniques are being developed to streamline the characterization of entire neural circuits. Even if this 'connectome' approach is successful, it will represent only a static description of neural circuits. Thus, a fundamental question in neuroscience is to understand how information is dynamically represented by neural populations. In this thesis, I studied two main aspects of dynamical population codes. ^ First, I studied how the exposure or adaptation, for a fraction of a second to oriented gratings dynamically changes the population response of primary visual cortex neurons. The effects of adaptation to oriented gratings have been extensively explored in psychophysical and electrophysiological experiments. However, whether rapid adaptation might induce a change in the primary visual cortex's functional connectivity to dynamically impact the population coding accuracy is currently unknown. To address this issue, we performed multi-electrode recordings in primary visual cortex, where adaptation has been previously shown to induce changes in the selectivity and response amplitude of individual neurons. We found that adaptation improves the population coding accuracy. The improvement was more prominent for iso- and orthogonal orientation adaptation, consistent with previously reported psychophysical experiments. We propose that selective decorrelation is a metabolically inexpensive mechanism that the visual system employs to dynamically adapt the neural responses to the statistics of the input stimuli to improve coding efficiency. ^ Second, I investigated how ongoing activity modulates orientation coding in single neurons, neural populations and behavior. Cortical networks are never silent even in the absence of external stimulation. The ongoing activity can account for up to 80% of the metabolic energy consumed by the brain. Thus, a fundamental question is to understand the functional role of ongoing activity and its impact on neural computations. I studied how the orientation coding by individual neurons and cell populations in primary visual cortex depend on the spontaneous activity before stimulus presentation. We hypothesized that since the ongoing activity of nearby neurons is strongly correlated, it would influence the ability of the entire population of orientation-selective cells to process orientation depending on the prestimulus spontaneous state. Our findings demonstrate that ongoing activity dynamically filters incoming stimuli to shape the accuracy of orientation coding by individual neurons and cell populations and this interaction affects behavioral performance. In summary, this thesis is a contribution to the study of how dynamic internal states such as rapid adaptation and ongoing activity modulate the population code accuracy. ^

Effects of early and late lesion of orbital frontal cortex on visual processing of faces in rhesus macaques (Macaca mulatta)

Many mental disorders disrupt social skills, yet few studies have examined how the brain processes social information. Functional neuroimaging, neuroconnectivity and electrophysiological studies suggest that orbital frontal cortex plays important roles in social cognition, including the analysis of information from faces, which are important cues in social interactions. Studies in humans and non-human primates show that damage to orbital frontal cortex produces social behavior impairments, including abnormal aggression, but these studies have failed to determine whether damage to this area impairs face processing. In addition, it is not known whether damage early in life is more detrimental than damage in adulthood. This study examined whether orbital frontal cortex is necessary for the discrimination of face identity and facial expressions, and for appropriate behavioral responses to aggressive (threatening) facial expressions. Rhesus monkeys (Macaca mulatta) received selective lesions of orbital frontal cortex as newborns or adults. As adults, these animals were compared with sham-operated controls on their ability to discriminate between faces of individual monkeys and between different facial expressions of emotion. A passive visual paired-comparison task with standardized rhesus monkey face stimuli was designed and used to assess discrimination. In addition, looking behavior toward aggressive expressions was assessed and compared with that of normal control animals. The results showed that lesion of orbital frontal cortex (1) may impair discrimination between faces of individual monkeys, (2) does not impair facial expression discrimination, and (3) changes the amount of time spent looking at aggressive (threatening) facial expressions depending on the context. The effects of early and late lesions did not differ. Thus, orbital frontal cortex appears to be part of the neural circuitry for recognizing individuals and for modulating the response to aggression in faces, and the plasticity of the immature brain does not allow for recovery of these functions when the damage occurs early in life. This study opens new avenues for the assessment of rhesus monkey face processing and the neural basis of social cognition, and allows a better understanding of the nature of the neuropathology in patients with mental disorders that disrupt social behavior, such as autism. ^

Using small area estimation and geographic information systems technology to target health services for the uninsured

The three articles that comprise this dissertation describe how small area estimation and geographic information systems (GIS) technologies can be integrated to provide useful information about the number of uninsured and where they are located. Comprehensive data about the numbers and characteristics of the uninsured are typically only available from surveys. Utilization and administrative data are poor proxies from which to develop this information. Those who cannot access services are unlikely to be fully captured, either by health care provider utilization data or by state and local administrative data. In the absence of direct measures, a well-developed estimation of the local uninsured count or rate can prove valuable when assessing the unmet health service needs of this population. However, the fact that these are “estimates” increases the chances that results will be rejected or, at best, treated with suspicion. The visual impact and spatial analysis capabilities afforded by geographic information systems (GIS) technology can strengthen the likelihood of acceptance of area estimates by those most likely to benefit from the information, including health planners and policy makers. ^ The first article describes how uninsured estimates are currently being performed in the Houston metropolitan region. It details the synthetic model used to calculate numbers and percentages of uninsured, and how the resulting estimates are integrated into a GIS. The second article compares the estimation method of the first article with one currently used by the Texas State Data Center to estimate numbers of uninsured for all Texas counties. Estimates are developed for census tracts in Harris County, using both models with the same data sets. The results are statistically compared. The third article describes a new, revised synthetic method that is being tested to provide uninsured estimates at sub-county levels for eight counties in the Houston metropolitan area. It is being designed to replicate the same categorical results provided by a current U.S. Census Bureau estimation method. The estimates calculated by this revised model are compared to the most recent U.S. Census Bureau estimates, using the same areas and population categories. ^

Accesibilidad digital para usuarios con discapacidad visual en entornos educativos

Este artículo presenta los avances de un trabajo de tesis de Magister en Tecnología Informática Aplicada en Educación de la Facultad de Informática de la UNLP, cuyo tema es “Accesibilidad digital para usuarios con limitaciones visuales y su relación con espacios virtuales de aprendizaje". 2 Aborda el tema de accesibilidad digital desde el marco teórico seleccionado y se mencionan los ejes de análisis dentro del marco del uso de las tecnologías como herramientas que favorecen la cognición. Se enuncia la propuesta de tesis y los primeros resultados. Se realiza una primera comparación donde se discuten las ventajas y desventajas de los espacios digitales al acceder mediante los lectores de pantalla, permitiendo establecer líneas de trabajo futuro.

Metadata Visualization of Cultural Heritage Information within a Collaborative Environment

Cultural content on the Web is available in various domains (cultural objects, datasets, geospatial data, moving images, scholarly texts and visual resources), concerns various topics, is written in different languages, targeted to both laymen and experts, and provided by different communities (libraries, archives museums and information industry) and individuals (Figure 1). The integration of information technologies and cultural heritage content on the Web is expected to have an impact on everyday life from the point of view of institutions, communities and individuals. In particular, collaborative environment scan recreate 3D navigable worlds that can offer new insights into our cultural heritage (Chan 2007). However, the main barrier is to find and relate cultural heritage information by end-users of cultural contents, as well as by organisations and communities managing and producing them. In this paper, we explore several visualisation techniques for supporting cultural interfaces, where the role of metadata is essential for supporting the search and communication among end-users (Figure 2). A conceptual framework was developed to integrate the data, purpose, technology, impact, and form components of a collaborative environment, Our preliminary results show that collaborative environments can help with cultural heritage information sharing and communication tasks because of the way in which they provide a visual context to end-users. They can be regarded as distributed virtual reality systems that offer graphically realised, potentially infinite, digital information landscapes. Moreover, collaborative environments also provide a new way of interaction between an end-user and a cultural heritage data set. Finally, the visualisation of metadata of a dataset plays an important role in helping end-users in their search for heritage contents on the Web.

Atlas visual de cincuenta y siete años de arquitectura

En 1929 aparece el primer número de AA (L’architecture d’aujourd’hui), en 1932 existe un número-Monografía sobre los hermanos Perret, escrita por Pierre Vago, en 1946 se consolida como revista mensual y bajo la fundación de Andre Bloc. El primer número de AA que tengo en mi biblioteca es el número 34 (febrero-Marzo) de 1951. Mediante la lectura observada de una colección como AA, la determinación de unos capítulos representativos y la elección de imágenes de su tiempo se explican estos 57 años de arquitectura, cuyos resultados de un proceso temporal disfrutamos desde hace aproximadamente veinte años. A principio de los años cincuenta un grupo de jóvenes arquitectos, denso e intercomunicado en los congresos CIAM se propone situar la realidad de la arquitectura en los principios y realidades de su tiempo y de los que se intuyen futuro. Resultados de la Segunda Gran Guerra no son solo tragedias humanas sino gran investigación y desarrollo concretada industrialmente, enormes movimientos de personas en Europa y una sociedad enormemente optimista en USA, todo esto producirá las grandes transformaciones sociales de los 60’ y sus concreciones tecnológicas, políticas y desarrollo. Muchos arquitectos, publicaciones, concursos o decisiones políticas o privadas han producido el catalogo de arquitecturas de estos años, desde el CIAM IX hasta el POMPIDOU, desde la casa GEHRY hasta el KUNSTHAL, desde BRASILIA hasta SIDNEY, desde COPLEJIDAD Y CONTRADICCIÓN hasta DELIRIOS DE NY, desde OSAKA hasta MUNICH. En todas han existido un esfuerzo enorme por concretar la realidad de nuestras aspiraciones desde las puramente ideológicas de introspección social, hasta las concreciones de imagen directa. Varias líneas he abierto en mi proceso de investigación, las he llamado “anillos” porque todas estas líneas tienen similitud con los “anillos de crecimiento” de los árboles en cuanto a como se presentan en la estructura de formación y ha la cantidad de información no solo interna sino externa que aportan sobre la estructura árbol, su medio y la historia. Igual que podemos saber las temperaturas o las pluviometría que cubrieron Europa en la edad media solo estudiando los anillos de crecimiento de nuestro árboles (su grosor), de igual forma repasando LOS CONCURSOS y sus resultados que existieron en los últimos cincuenta años, podemos entender las aspiraciones y concreciones de las sociedades y sus arquitectos en este tiempo. Cuatro capítulos, los mas determinantes son los elegidos para dar cuerpo a una TESIS de tamaño capaz: Las ideas, el futuro, las referencias y el presente son los capítulos que de forma visual intentan explicar el fruto arquitectónico, sus aspiraciones y sus concreciones. Las ideas sin ninguna duda, pertenecen a los padres de nuestro tiempo, son las del Team X, la reflexión sobre lo perecedero, las realidades programáticas, densidades o lo publico-privado son solo planetas en el universo de sus ideas. El futuro lo trazaron aquellos que empezaron a investigar, concretar o reflexionar sobre la incidencia tanto de los procesos industriales con sus nuevos materiales como de las nuevas concreciones urbanas que los movimientos migratorios producirían en las ciudades. Las referencias son las bibliotecas de carácter informativo-visual que han generado nuestro inventario icónico. El presente son las imágenes de referencia de nuestro tiempo-mediático, no solo las produce un arquitecto (en este caso R.Koolhas), pero si que es verdad que en las imágenes arquitectónicas de OMA se concreta todo el catalogo de arquitecturas del presente. ENGLISH SUMMARY The fisrt AA (l´Architecture d´Aujourd´hui) issue was published in 1929, three years later, in 1932, a monographic issue on Perret brothers was written by Pierre Vago and in 1946 the magazine was strongly established as a monthly publication under the direction of André Bloc. The oldest copy I own on my bookshelves is nº 34 printed in February-March 1951. While carefully reading a collection such as AA we are able to extract representative chapters and images that can explain a linear process lasting 57 years of fruitful architectural production of which consequences we have been enjoying the past twenty years. In the early fifties a compact group of young architects linked by the CIAM congress decided to encompass architectural reality to the needs and principles of their time. Not only big human tragedies arose from the Second World War but also some of the fastest industrial inventions due to a powerful will to development, that altogether with european migrations and a high standard of optimism in the United States headed to the peak transformations of the sixties and their technological and political development. A bunch of architects, magazines and architectural competitions sided by political and private decisions produced the architectural catalogue of those years, from CIAM IX to the Pompidou art centre, from Gerhy´s house to the Kunsthal museum, from Brasilia to Sidney, from “Complexity and Contradiction“ to “Delirious NY” and from Osaka all the way to Munich. All of them carried a vast effort towards the concretion of will, from social introspection to a more effective development of images. Several paths run across my investigation, namely “the rings”, as they tend to behave as a growing structure like a tree trunk, providing internal and external information not only of the vegetal element but also of the environment and events crossing its time. In the same direction as we are able to predict the weather in the Middle Age by means of studying our forests, we can use the architectural competitions ant their results for the past fifty years to understand the will and ambitions of these developing societies and their architects. To give shape to a sizeable thesis the selected information has been packed in four chapters: Ideas, Future, References and Present, each of them structured as an Image bank visualizing the architectural product, its will and specific ambition. The first group, Ideas, is devoted entirely to the step-fathers of present architecture, with ideas that belong to TEAM X and embrace the reflection about the transitory, the programmatic reality, density or the public-private debate as wandering planets of their ideal universe. The second group is dedicated to a Future that was traced by those engaged on industrial processes and new material investigation together with some others exploring new urban concretions brought to existence by the pressure of the after war migrations. The third group, References, have been shaped as a stock-list containing all our iconic cross-references. The last group, Present, brings together the icons of this media-time we live in and not only those produced by one single architect (Rem Koolhaas) even if his production embodies all architectural references at the moment.

Improving target localization accuracy of wireless visual sensor networks

This paper discusses the target localization problem of wireless visual sensor networks. Specifically, each node with a low-resolution camera extracts multiple feature points to represent the target at the sensor node level. A statistical method of merging the position information of different sensor nodes to select the most correlated feature point pair at the base station is presented. This method releases the influence of the accuracy of target extraction on the accuracy of target localization in universal coordinate system. Simulations show that, compared with other relative approach, our proposed method can generate more desirable target localization's accuracy, and it has a better trade-off between camera node usage and localization accuracy.

Generación y Gestión Optimizadas de la Base de Datos de un Visual para su Implementación en un Simulador de Formación

Los Sistemas de Información Geográfica están desarrollados para gestionar grandes volúmenes de datos, y disponen de numerosas funcionalidades orientadas a la captura, almacenamiento, edición, organización, procesado, análisis, o a la representación de información geográficamente referenciada. Por otro lado, los simuladores industriales para entrenamiento en tareas de conducción son aplicaciones en tiempo real que necesitan de un entorno virtual, ya sea geoespecífico, geogenérico, o combinación de ambos tipos, sobre el cual se ejecutarán los programas propios de la simulación. Este entorno, en última instancia, constituye un lugar geográfico, con sus características específicas geométricas, de aspecto, funcionales, topológicas, etc. Al conjunto de elementos que permiten la creación del entorno virtual de simulación dentro del cual se puede mover el usuario del simulador se denomina habitualmente Base de Datos del Visual (BDV). La idea principal del trabajo que se desarrolla aborda un tema del máximo interés en el campo de los simuladores industriales de formación, como es el problema que presenta el análisis, la estructuración, y la descripción de los entornos virtuales a emplear en los grandes simuladores de conducción. En este artículo se propone una metodología de trabajo en la que se aprovechan las capacidades y ventajas de los Sistemas de Información Geográfica para organizar, optimizar y gestionar la base de datos visual del simulador, y para mejorar la calidad y el rendimiento del simulador en general. ABSTRACT Geographic Information Systems are developed to handle enormous volumes of data and are equipped with numerous functionalities intended to capture, store, edit, organise, process and analyse or represent the geographically referenced information. On the other hand, industrial simulators for driver training are real-time applications that require a virtual environment, either geospecific, geogeneric or a combination of the two, over which the simulation programs will be run. In the final instance, this environment constitutes a geographic location with its specific characteristics of geometry, appearance, functionality, topography, etc. The set of elements that enables the virtual simulation environment to be created and in which the simulator user can move, is usually called the Visual Database (VDB). The main idea behind the work being developed approaches a topic that is of major interest in the field of industrial training simulators, which is the problem of analysing, structuring and describing the virtual environments to be used in large driving simulators. This paper sets out a methodology that uses the capabilities and benefits of Geographic Information Systems for organising, optimising and managing the visual Database of the simulator and for generally enhancing the quality and performance of the simulator.

Towards a ground navigation system based in visual feedback provided by a mini UAV

This paper addresses initial efforts to develop a navigation system for ground vehicles supported by visual feedback from a mini aerial vehicle. A visual-based algorithm computes the ground vehicle pose in the world frame, as well as possible obstacles within the ground vehicle pathway. Relying on that information, a navigation and obstacle avoidance system is used to re-plan the ground vehicle trajectory, ensuring an optimal detour. Finally, some experiments are presented employing a unmanned ground vehicle (UGV) and a low cost mini unmanned aerial vehicle (UAV).

Mapping the visual landscape quality in Europe using physical attributes

he inclusion of environmental care data in the decision-making process should be based on the results obtained after scienti?cally evaluating different environmental variables. Herein, a European landscape geographic model is presented. This landscape map would allow the environmental care variable ?visual landscape?, along with other information related to vegetation, geology, soils, cultural variables, etc., to be integrated into the planning process. The methodology used is not new since it has already been tested in Spain by the authors. Nevertheless, the model was adapted to cope with the much more extensive territory of the European Union. This meant dealing with computational dif?culties, and a lack of information. The result of this work is a raster map (100 m cell size) that evaluates landscape quality in Europe by dividing the area into seven visual quality classes. This is a practical tool for territorial development that will facilitate the environmental assessment of plans, such as infrastructure plans, within a strategic pan-European framework.

MEDVIR: 3D visual interface applied to gene profile analisys.

The origins for this work arise in response to the increasing need for biologists and doctors to obtain tools for visual analysis of data. When dealing with multidimensional data, such as medical data, the traditional data mining techniques can be a tedious and complex task, even to some medical experts. Therefore, it is necessary to develop useful visualization techniques that can complement the expert’s criterion, and at the same time visually stimulate and make easier the process of obtaining knowledge from a dataset. Thus, the process of interpretation and understanding of the data can be greatly enriched. Multidimensionality is inherent to any medical data, requiring a time-consuming effort to get a clinical useful outcome. Unfortunately, both clinicians and biologists are not trained in managing more than four dimensions. Specifically, we were aimed to design a 3D visual interface for gene profile analysis easy in order to be used both by medical and biologist experts. In this way, a new analysis method is proposed: MedVir. This is a simple and intuitive analysis mechanism based on the visualization of any multidimensional medical data in a three dimensional space that allows interaction with experts in order to collaborate and enrich this representation. In other words, MedVir makes a powerful reduction in data dimensionality in order to represent the original information into a three dimensional environment. The experts can interact with the data and draw conclusions in a visual and quickly way.