Brain-Computer Interfaces, Virtual Reality, and Videogames

Major challenges must be tackled for brain-computer interfaces to mature into an established communications medium for VR applications, which will range from basic neuroscience studies to developing optimal peripherals and mental gamepads and more efficient brain-signal processing techniques.

Brain Computer Interface for Virtual Reality Control

A brain-computer interface (BCI) is a new communication channel between the human brain and a computer. Applications of BCI systems comprise the restoration of movements, communication and environmental control. In this study experiments were made that used the BCI system to control or to navigate in virtual environments (VE) just by thoughts. BCI experiments for navigation in VR were conducted so far with synchronous BCI and asynchronous BCI systems. The synchronous BCI analyzes the EEG patterns in a predefined time window and has 2 to 3 degrees of freedom.

Effects of P300-based BCI use on reported presence in a virtual environment

Brain-computer interfaces (BCIs) are becoming more and more popular as an input device for virtual worlds and computer games. Depending on their function, a major drawback is the mental workload associated with their use and there is significant effort and training required to effectively control them. In this paper, we present two studies assessing how mental workload of a P300-based BCI affects participants" reported sense of presence in a virtual environment (VE). In the first study, we employ a BCI exploiting the P300 event-related potential (ERP) that allows control of over 200 items in a virtual apartment. In the second study, the BCI is replaced by a gaze-based selection method coupled with wand navigation. In both studies, overall performance is measured and individual presence scores are assessed by means of a short questionnaire. The results suggest that there is no immediate benefit for visualizing events in the VE triggered by the BCI and that no learning about the layout of the virtual space takes place. In order to alleviate this, we propose that future P300-based BCIs in VR are set up so as require users to make some inference about the virtual space so that they become aware of it,which is likely to lead to higher reported presence.

Inducing illusory ownership of a virtual body

We discuss three experiments that investigate how virtual limbs and bodies can come to feel like real limbs and bodies. The fi rst experiment shows that an illusion of ownership of a virtual arm appearing to project out of a person"s shoulder can be produced by tactile stimulation on a person"s hidden real hand and synchronous stimulation on the seen virtual hand. The second shows that the illusion can be produced by synchronous movement of the person"s hidden real hand and a virtual hand. The third shows that a weaker form of the illusion can be produced when a brain-computer interface is employed to move the virtual hand by means of motor imagery without any tactile stimulation. We discuss related studies that indicate that the ownership illusion may be generated for an entire body. This has important implications for the scientific understanding of body ownership and several practical applications.

Elementos para la evaluación de interfaces de consulta de bases de datos

La interfaz de consulta de una base de datos en web sirve para establecer la comunicación entre personas que buscan información y los sistemas de recuperación de la información, siendo una de las partes más importantes del diseño conceptual de una base de datos. La interfaz de consulta está formada por un conjunto de páginas de las cuales podríamos destacar las siguientes: página de consulta, resultados, visualización del documento completo, información general y ayudas. El objetivo del texto consiste en determinar cuáles son los elementos básicos que han de estar presentes en cada una de las páginas antes citadas para contribuir a facilitar el proceso de recuperación de la información por parte de los usuarios.

Collaborative explicit plasticity framework: a conceptual scheme for the generation of plastic and group-aware user interfaces

The advent of new advances in mobile computing has changed the manner we do our daily work, even enabling us to perform collaborative activities. However, current groupware approaches do not offer an integrating and efficient solution that jointly tackles the flexibility and heterogeneity inherent to mobility as well as the awareness aspects intrinsic to collaborative environments. Issues related to the diversity of contexts of use are collected under the term plasticity. A great amount of tools have emerged offering a solution to some of these issues, although always focused on individual scenarios. We are working on reusing and specializing some already existing plasticity tools to the groupware design. The aim is to offer the benefits from plasticity and awareness jointly, trying to reach a real collaboration and a deeper understanding of multi-environment groupware scenarios. In particular, this paper presents a conceptual framework aimed at being a reference for the generation of plastic User Interfaces for collaborative environments in a systematic and comprehensive way. Starting from a previous conceptual framework for individual environments, inspired on the model-based approach, we introduce specific components and considerations related to groupware.

O6-Methylguanine-DNA methyltransferase protein expression by immunohistochemistry in brain and non-brain systemic tumours: systematic review and meta-analysis of correlation with methylation-specific polymerase chain reaction

Background: The DNA repair protein O6-Methylguanine-DNA methyltransferase (MGMT) confers resistance to alkylating agents. Several methods have been applied to its analysis, with methylation-specific polymerase chain reaction (MSP) the most commonly used for promoter methylation study, while immunohistochemistry (IHC) has become the most frequently used for the detection of MGMT protein expression. Agreement on the best and most reliable technique for evaluating MGMT status remains unsettled. The aim of this study was to perform a systematic review and meta-analysis of the correlation between IHC and MSP. Methods A computer-aided search of MEDLINE (1950-October 2009), EBSCO (1966-October 2009) and EMBASE (1974-October 2009) was performed for relevant publications. Studies meeting inclusion criteria were those comparing MGMT protein expression by IHC with MGMT promoter methylation by MSP in the same cohort of patients. Methodological quality was assessed by using the QUADAS and STARD instruments. Previously published guidelines were followed for meta-analysis performance. Results Of 254 studies identified as eligible for full-text review, 52 (20.5%) met the inclusion criteria. The review showed that results of MGMT protein expression by IHC are not in close agreement with those obtained with MSP. Moreover, type of tumour (primary brain tumour vs others) was an independent covariate of accuracy estimates in the meta-regression analysis beyond the cut-off value. Conclusions Protein expression assessed by IHC alone fails to reflect the promoter methylation status of MGMT. Thus, in attempts at clinical diagnosis the two methods seem to select different groups of patients and should not be used interchangeably.

Classifier combination for in vivo magnetic resonance spectra of brain tumours

In this paper we present a multi-stage classifier for magnetic resonance spectra of human brain tumours which is being developed as part of a decision support system for radiologists. The basic idea is to decompose a complex classification scheme into a sequence of classifiers, each specialising in different classes of tumours and trying to reproducepart of the WHO classification hierarchy. Each stage uses a particular set of classification features, which are selected using a combination of classical statistical analysis, splitting performance and previous knowledge.Classifiers with different behaviour are combined using a simple voting scheme in order to extract different error patterns: LDA, decision trees and the k-NN classifier. A special label named "unknown¿ is used when the outcomes of the different classifiers disagree. Cascading is alsoused to incorporate class distances computed using LDA into decision trees. Both cascading and voting are effective tools to improve classification accuracy. Experiments also show that it is possible to extract useful information from the classification process itself in order to helpusers (clinicians and radiologists) to make more accurate predictions and reduce the number of possible classification mistakes.

Sistema de monitorització Open Source: projecte d'empresa per Computer Technology Catalunya

L’objectiu del projecte consisteix en l’estudi, simulació i implantació d’un conjunt d’aplicacions que permeten tenir un control sobre possibles problemes que puguin succeir a la nostra xarxa. Aquest projecte és la solució als problemes de detecció d’errors en el funcionament de les infraestructures de networking de les que disposen els nostres clients.

Estudi d'interfícies multitàctils i multiusuàri

Actualment, les interfícies multitàctils estan guanyant popularitat, tant entre els usuaris com entre els desenvolupadors i fabricants. En aquest projecte s'estudien les interfícies multitàctils basades en visió per computador: el seu funcionament, la seva construcció i la implementació del software que permet la interacció amb més d'un dit simultàniament. En la memòria es presenta aquest estudi, com s'ha construït una taula i els resultats que s'han obtingut amb ella.

Generación de interfaces para aplicaciones por línea de comandos

Generación dinámica de interfaces web basadas en ficheros descriptivos XML para el control de la parametrización compleja y ejecución de programas por línea de comandos. La necesidad surge con la aplicación mlcoalsim, utilizada por investigadores de la UAB, cuya parametrización requiere la edición manual de un fichero de texto la sintaxis del cual es complicada y pesada. Con la generación de interfaces web se pretende ayudar a los usuarios en la correcta parametrización y ejecución de aplicaciones como mlcoalsim.

Diseño centrado en el usuario y usabilidad en entorno táctil

En este trabajo se realiza un prototipo siguiendo un diseño centrado en el usuario, además se estudiaran los distintos tipos de pantallas táctiles que existen actualmente en el mercado y la forma de cómo conseguir una aplicación fácil y manejable.

Accessibilitat web : cas d'anàlisi a partir de les WCAG 1.0 i WCAG 2.0

El document analitza, de forma manual i detallada, l'accessibilitat de 10 pàgines web del portal de la UOC en base a les 14 pautes i 65 punts de validació de les WCAG 1.0 i en base als quatre principis de les WCAG 2.0 que a la vegada s'organitzen en 12 directius i 61 criteris de conformitat.

Análisis de usabilidad y diseño de un supermercado online

En este trabajo se realiza un estudio de usabilidad para la elaboración óptima de una Web de un supermercado de alimentación online. Para tal fin, se sigue la filosofía del Diseño Centrado en el Usuario. En primer lugar, se presenta un análisis del problema de cara a identificar los requisitos básicos de usabilidad que necesita una Web de esta tipología: se estudia la literatura previa sobre el tema, se consulta a los usuarios y se realiza un análisis comparativo de las principales Webs de supermercados online de ámbito nacional. En segundo lugar, se procede a la elaboración de un prototipo basado en la información recogida en la fase de análisis, y teniendo en cuenta la estructura mental de los usuarios en cuanto a la organización de los productos, obtenida mediante la técnica del card sorting. Finalmente, se procede a evaluar la calidad del prototipo elaborado con una evaluación heurística llevada a cabo por expertos. De todo ello se obtienen una serie de recomendaciones que todo sitio Web de comercio electrónico (en especial supermercados de alimentación) debería cumplir si quiere ofrecer una Web adaptada a las necesidades del usuario.

La accesibilidad web en los repositorios institucionales : la UOC a examen

Breve revisión de la accesibilidad web del repositorio institucional de la UOC e información sobre herramientas de validación automática de sitios web.