Influencia de los sistemas Brain-Computer Interface basados en Neurofeedback en las características de la red cerebral

Las técnicas de Neurofeedback (NF) permiten a sus usuarios, mediante el uso de sistemas Brain-Computer Interfaces (BCI), la modulación voluntaria de determinados ritmos de la actividad cerebral. En este trabajo se presenta un análisis exploratorio de los efectos del NF desde una perspectiva novedosa en este campo de investigación: la teoría de redes. Para ello, se empleó las señales de electroencefalograma (EEG) registradas durante un estudio que constó de 6 sesiones de NF. Los sujetos fueron divididos en un grupo de entrenamiento (GE), que entrenó su actividad theta (4 – 8 Hz), y un grupo de placebo (GP). Las redes cerebrales se construyeron a partir de un análisis de conectividad funcional empleando Phase Lag Index (PLV) en las bandas theta (4 – 8 Hz) y alpha (8 – 13 Hz). Para analizar la estructura de las redes durante el NF se estudió el Clustering Coefficient (CLC) y el Characteristic Path Length (PL). La comparación de estas características entre GE y GP mostró unos mayores valores de CLC en el GE en theta y alpha, siendo significativa la diferencia (p-valor corregido < 0.001) en esta última banda. Por otro lado, el PL fue igual para ambos grupos y ambas bandas de frecuencia. Estos resultados podrían sugerir la utilidad del CLC como indicador del proceso de aprendizaje de neuro-modulación durante el entrenamiento NF, así como la utilidad de la metodología de teoría de redes para caracterizar los efectos del NF en la actividad cerebral.Este estudio ha sido financiado por los proyectos TED2021-129915B-I00, PID2020-115468RB-I00 y RTC2019-007350-1 financiadas por el Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación/10. 13039/501100011033/', FEDER Una forma de hacer Europa; y por ‘Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER- BBN)’ a través de ‘Instituto de Salud Carlos III’. D. Marcos-Martínez y S. Pérez-Velasco son beneficiarios de una ayuda PIF de la Consejería de Educación de la Junta de Castilla y León

The European Solar Telescope

The European Solar Telescope (EST) is a project aimed at studying the magnetic connectivity of the solar atmosphere, from the deep photosphere to the upper chromosphere. Its design combines the knowledge and expertise gathered by the European solar physics community during the construction and operation of state-of-the-art solar telescopes operating in visible and near-infrared wavelengths: the Swedish 1m Solar Telescope, the German Vacuum Tower Telescope and GREGOR, the French Télescope Héliographique pour l'Étude du Magnétisme et des Instabilités Solaires, and the Dutch Open Telescope. With its 4.2 m primary mirror and an open configuration, EST will become the most powerful European ground-based facility to study the Sun in the coming decades in the visible and near-infrared bands. EST uses the most innovative technological advances: the first adaptive secondary mirror ever used in a solar telescope, a complex multi-conjugate adaptive optics with deformable mirrors that form part of the optical design in a natural way, a polarimetrically compensated telescope design that eliminates the complex temporal variation and wavelength dependence of the telescope Mueller matrix, and an instrument suite containing several (etalon-based) tunable imaging spectropolarimeters and several integral field unit spectropolarimeters. This publication summarises some fundamental science questions that can be addressed with the telescope, together with a complete description of its major subsystems

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

The European Solar Telescope

The European Solar Telescope (EST) is a project aimed at studying the magnetic connectivity of the solar atmosphere, from the deep photosphere to the upper chromosphere. Its design combines the knowledge and expertise gathered by the European solar physics community during the construction and operation of state-of-the-art solar telescopes operating in visible and near-infrared wavelengths: the Swedish 1m Solar Telescope, the German Vacuum Tower Telescope and GREGOR, the French Télescope Héliographique pour l’Étude du Magnétisme et des Instabilités Solaires, and the Dutch Open Telescope. With its 4.2 m primary mirror and an open configuration, EST will become the most powerful European ground-based facility to study the Sun in the coming decades in the visible and near-infrared bands. EST uses the most innovative technological advances: the first adaptive secondary mirror ever used in a solar telescope, a complex multi-conjugate adaptive optics with deformable mirrors that form part of the optical design in a natural way, a polarimetrically compensated telescope design that eliminates the complex temporal variation and wavelength dependence of the telescope Mueller matrix, and an instrument suite containing several (etalon-based) tunable imaging spectropolarimeters and several integral field unit spectropolarimeters. This publication summarises some fundamental science questions that can be addressed with the telescope, together with a complete description of its major subsystems

P300-Based Brain-Computer Interface Channel Selection using Swarm Intelligence

[ES] Los sistemas Brain-Computer Interface (BCI) se definen como sistemas de comunicación que monitorizan la actividad cerebral y traducen determinadas características, correspondientes a las intenciones del usuario, en comandos de control de un dispositivo. La selección de canales en los sistemas BCI es fundamental para evitar el sobre-entrenamiento del clasificador, reducir la carga computacional y aumentar la comodidad del usuario. A pesar de que se han desarrollado varios algoritmos con anterioridad para tal fin, las metaheurísticas basadas en inteligencia de enjambre aún no han sido suficientemente explotadas en los sistemas BCI basados en potenciales P300. En este estudio se muestra una comparativa entre cinco métodos de enjambre, basados en el comportamiento de sistemas biológicos, aplicados con el objetivo de optimizar la selección de canales en este tipo de sistemas. Los métodos se han evaluado sobre la base de datos de la “III BCI Competition 2005”, reportando precisiones similares o, en algunos casos, incluso más altas que las obtenidas sin realizar ningún tipo de selección. Dado que los cinco métodos se han demostrado capaces de disminuir drásticamente los 64 canales originales a menos de la mitad sin comprometer el rendimiento del sistema, así como de superar el conjunto típico de 8 canales y el método backward elimination, se concluye que todos ellos son adecuados para su aplicación en la selección de canales en sistemas P300-BCI.[EN] Brain-Computer Interfaces (BCI) are direct communication pathways between the brain and the environment that translate certain features, which correspond to users’ intentions, into device control commands. Channel selection in BCI systems is essential to avoid over-fitting, to reduce the computational cost and to increase the users’ comfort. Although several algorithms have previously developed for that purpose, metaheuristics based on swarm intelligence have not been exploited yet in P300-based BCI systems. In this study, a comparative among five different swarm methods, based on the behavior of biological systems, is shown. Those methods have been applied in order to optimize the channel selection procedure in this kind of systems, and have been tested with the ‘III BCI Competition 2005’ database II. Results show that the five methods can achieve similar or even higher accuracies than that obtained without performing any channel selection procedure. Owing to the fact that all the applied methods are able to drastically reduce the required number of channels without compromising the system performance, as well as to overcome the common 8-channel set and the backward elimination algorithm, we conclude that all of them are suitable for use in the P300-BCI systems channel selection procedure.Este estudio se ha financiado parcialmente mediante el proyecto TEC2014-53196-R del Ministerio de Economía y Competitividad (MINECO) y FEDER, y el proyecto VA037U16 de la Consejería de Educación de la Junta de Castilla y León. V. Martínez-Cagigal se encuentra financiado por un contrato de “Promocion de Empleo Joven e Implantación de la Garantía Juvenil del MINECO y la Universidad de Valladolid.Martínez-Cagigal, V.; Hornero, R. (2017). Selección de Canales en Sistemas BCI basados en Potenciales P300 mediante Inteligencia de Enjambre. 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Evolution of project-based learning in small groups in environmental engineering courses

This work presents the assessment of the development and evolution of an active methodology (Project-Based Learning –PBL-) implemented on the course “Unit Operations in Environmental Engineering”, within the bachelor’s degree in Environmental Engineering, with the purpose of decreasing the dropout rate in this course. After the initial design and implementation of this methodology during the first academic year (12/13), different modifications were adopted in the following ones (13-14, 14-15 & 15-16) in order to optimize the student’s and professor’s work load as well as correct some malfunctions observed in the initial design of the PBL. This active methodology seeks to make students the main architects of their own learning processes. Accordingly, they have to identify their learning needs, which is a highly motivating approach both for their curricular development and for attaining the required learning outcomes in this field of knowledge. The results obtained show that working in small teams (cooperative work) enhances each group member’s self–learning capabilities. Moreover, academic marks improve when compared to traditional learning methodologies. Nevertheless, the implementation of more active methodologies, such as project-based learning, in small groups has certain specific characteristics. In this case it has been implemented simultaneously in two different groups of 10 students each one. Such small groups are more heterogeneoussince the presence of two highly motivated students or not can vary or affect the whole group’s attitude and academic results

Brain-computer interfaces based on code-modulated visual evoked potentials (c-VEP): A literature review

Objective. Code-modulated visual evoked potentials (c-VEP) have been consolidated in recent years as robust control signals capable of providing non-invasive brain–computer interfaces (BCIs) for reliable, high-speed communication. Their usefulness for communication and control purposes has been reflected in an exponential increase of related articles in the last decade. The aim of this review is to provide a comprehensive overview of the literature to gain understanding of the existing research on c-VEP-based BCIs, since its inception (1984) until today (2021), as well as to identify promising future research lines. Approach. The literature review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. After assessing the eligibility of journal manuscripts, conferences, book chapters and non-indexed documents, a total of 70 studies were included. A comprehensive analysis of the main characteristics and design choices of c-VEP-based BCIs was discussed, including stimulation paradigms, signal processing, modeling responses, applications, etc. Main results. The literature review showed that state-of-the-art c-VEP-based BCIs are able to provide an accurate control of the system with a large number of commands, high selection speeds and even without calibration. In general, a lack of validation in real setups was observed, especially regarding the validation with disabled populations. Future work should be focused toward developing self-paced c-VEP-based portable BCIs applied in real-world environments that could exploit the unique benefits of c-VEP paradigms. Some aspects such as asynchrony, unsupervised training, or code optimization still require further research and development. Significance. Despite the growing popularity of c-VEP-based BCIs, to the best of our knowledge, this is the first literature review on the topic. In addition to providing a joint discussion of the advances in the field, some future lines of research are suggested to contribute to the development of reliable plug-and-play c-VEP-based BCIs