[show abstract][hide abstract] ABSTRACT: Conditioning of the upper-alpha rhythm to improve cognitive performance in healthy users by means of neurofeedback (NF) has been evaluated by several studies, however its effectiveness in people with severe cognitive deficits, such as depressive subjects, remains underexplored. This paper reports on a preliminary uncontrolled study to assess the effects of an upper-alpha NF intervention on patients with major depressive disorder (MDD). The NF effects on the EEG and cognitive performance were assessed. The EEG results showed that patients were able to modulate the upper-alpha rhythm in task-related EEG and during training, in both cases across the executions of the NF sessions, and pre and post within each session. The behavioral results showed the effectiveness of this intervention in a variety of cognitive functions such as working memory, attention, and executive functions.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 07/2013; 2013:6293-6296.
[show abstract][hide abstract] ABSTRACT: This paper reports on a single-session neurofeedback (NF) training procedure on the user-specific upper alpha band for cognitive enhancement in healthy users. A double-blind study was designed using a NF group and an active control group. Control group performed as the NF group but received sham feedback, minimizing the non-specific factors of training. This design aimed to (i) investigate upper alpha as a NF parameter, (ii) evaluate the NF effects on upper alpha during the execution of a cognitive task, and (iii) evaluate the effects on cognitive performance by means of a cognitive task and a battery of psychological tests. Results of EEG analysis show the key role of the feedback: only the NF group enhanced upper alpha during the training, and it led to a desynchronization increase during the execution of the cognitive task. Regarding the behavioral results, a strong learning effect was observed, with the NF group performing better in almost all measurements but many of them without statistical significance.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 08/2012; 2012:4643-7.
[show abstract][hide abstract] ABSTRACT: Desynchronization of sensorimotor rhythms (SMR) is a distinctive feature that provides a discriminative pattern for BCI operation. However, individuals such as BCI illiterates can not produce these discriminable patterns with sufficient reliability. Additionally, SMR desynchronization can become deteriorated or extinct in patients with spinal cord injury or a cerebrovascular accident. In all these situations BCI usage is compromised. This paper proposes an intervention based on neurofeedback training of the upper alpha band to improve SMR desynchronization. The feasibility of this intervention is demonstrated in a preliminary study in which five healthy subjects were trained to increase their upper alpha band power. Such increases produced higher SMR desynchronization and better discrimination between rest and execution states of a motor task.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 08/2012; 2012:4635-8.
[show abstract][hide abstract] ABSTRACT: This paper reports an electroencephalogram-based brain-actuated telepresence system to provide a user with presence in remote environments through a mobile robot, with access to the Internet. This system relies on a P300-based brain-computer interface (BCI) and a mobile robot with autonomous navigation and camera orientation capabilities. The shared-control strategy is built by the BCI decoding of task-related orders (selection of visible target destinations or exploration areas), which can be autonomously executed by the robot. The system was evaluated using five healthy participants in two consecutive steps: 1) screening and training of participants and 2) preestablished navigation and visual exploration telepresence tasks. On the basis of the results, the following evaluation studies are reported: 1) technical evaluation of the device and its main functionalities and 2) the users' behavior study. The overall result was that all participants were able to complete the designed tasks, reporting no failures, which shows the robustness of the system and its feasibility to solve tasks in real settings where joint navigation and visual exploration were needed. Furthermore, the participants showed great adaptation to the telepresence system.
IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics: a publication of the IEEE Systems, Man, and Cybernetics Society 12/2011; 42(3):793-804. · 3.01 Impact Factor
[show abstract][hide abstract] ABSTRACT: Neurofeedback (NF) training has revealed its therapeutical effects to treat a variety of neurological and psychological disorders, and has demonstrated its feasibility to improve certain cognitive aptitudes in healthy users. Although promising results of NF training exist in recent literature, the reliability of its effects remains questioned due to a lack of deep studies examining its impact on the human electrophysiology. This paper presents a NF training aimed at improving working memory performance in healthy users by the enhancement of upper alpha band. A user-specific training was used (upper alpha was determined for each user using the individual alpha frequency) to reduce the unspecific factors of training the entire classical alpha band as traditional NF usually does. EEG assessments in active and passive open-eyes state were conducted pre/post the NF training. The EEG analyses reveal the UA enhancement during the active tasks which is independent of other frequency bands. UA was also enhanced in the passive state but independence could not be obtained in lower alpha band. Finally, significant improvement in working memory was obtained with regard to a control group.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 08/2011; 2011:2327-30.
[show abstract][hide abstract] ABSTRACT: Neurofeedback therapies are an emerging technique used to treat neuropsychological disorders and to enhance cognitive performance. The feedback stimuli presented during the therapy are a key factor, serving as guidance throughout the entire learning process of the brain rhythms. Online decoding of these stimuli could be of great value to measure the compliance and adherence of the subject to the training. This paper describes the modeling and classification of performance feedback potentials with a Brain-Computer Interface (BCI), under a real neurofeedback training with five subjects. LDA and SVM classification techniques are compared and are both able to provide an average performance of approximately 80%.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 08/2011; 2011:4596-9.
[show abstract][hide abstract] ABSTRACT: Este artículo presenta un sistema de teleoperación multi-robot basado en una interfaz cerebro-computador que permite al usuario controlar de manera simultánea un número arbitrario de robots, únicamente con su actividad cerebral. El objetivo final de estos dispositivos está orientado hacia personas con fuertes deficiencias neuromusculares, ofreciendo telepresencia a través de un sistema robótico, con un modo de interacción via internet basado únicamente en el pensamiento. El presente trabajo es una extensión de un sistema de teleoperación cuyas innovaciones son el soporte para teleoperar N robots, y el uso de robots miniaturizados y portátiles (de dimensión dos órdenes de magnitud inferior respecto al original). La interfaz cerebro-computador está basada en EEG y el potencial evocado P300 como protocolo de control. Los robots están dotados de las capacidades de navegar, interactuar mediante el envío de alarmas, y percibir visualmente los entornos remotos. El sistema ha sido validado con dos usuarios sanos y el principal resultado es que ambos fueron capaces de completar exitosamente las tareas propuestas sin reportar ningún error, lo que demuestra la validez y alta robustez del prototipo en conjunto.
Revista Iberoamericana de Automatica e Informatica Industrial (RIAI) 04/2011; 8(2):16-23. · 0.38 Impact Factor
[show abstract][hide abstract] ABSTRACT: Brain-computer interfaces (BCIs) open a new valuable communication channel for people with severe neurological or motor degenerative diseases, such as ALS patients. On the other hand, the ability to teleoperate robots in a remote scenario provides a physical entity embodied in a real environment ready to perceive, explore, and interact. The combination of both functionalities provides a system with benefits for ALS patients in the context of neurorehabilitation or maintainment of the neural activity. This paper reports a BCI telepresence system which offers navigation, exploration and bidirectional communication, only controlled by brain activity; and an initial study of applicability with ALS patients. The results show the feasibility of this technology in real patients.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 01/2010; 2010:4476-80.
[show abstract][hide abstract] ABSTRACT: Resumen Este artículo describe dos dispositivos de rehabilitación cuyo funcionamiento se apoya únicamente en el pensamiento, ambos desarrollados en la Universidad de Zaragoza: el primero de ellos es una silla de ruedas con navegación autónoma y controlada con el pensamiento, mientras que el segundo es un robot controlado con el pensamiento para realizar tareas de teleoperación de manera remota. Básicamente, el usuario observa una reconstrucción virtual del entorno en tiempo real (silla de ruedas) o video real capturado por una cámara y con diferentes aspectos añadidos de realidad aumentada (robot), y se concentra en el área del espacio a alcanzar. Un proceso de estimulación visual elicita el fenómeno neurológico (P300 en este caso), el procesado de señal EEG detecta el objetivo, y a continuación es enviado al sistema de navegación autónomo, que conduce el dispositivo hasta el lugar deseado esquivando los obstáculos detectados. Estos sistemas han sido rigurosamente validados con diez usuarios sanos (cinco por cada aplicación). El resultado general es que todos los usuarios usaron correctamente los dispositivos con relativa facilidad y adaptabilidad.
[show abstract][hide abstract] ABSTRACT: This paper describes an EEG-based human brain-actuated robotic system, which allows performing navigation and visual exploration tasks between remote places via Internet, using only brain activity. In operation, two teleoperation modes can be combined: robot navigation and camera exploration. In both modes, the user faces a real-time video captured by the robot camera merged with augmented reality items. In this representation, the user concentrates on a target area to navigate to or visually explore; then, a visual stimulation process elicits the neurological phenomenon that enables the brain-computer system to decode the intentions of the user. In the navigation mode, the target destination is transferred to the autonomous navigation system, which drives the robot to the desired place while avoiding collisions with the obstacles detected by the laser scanner. In the camera mode, the camera is aligned with the target area to perform an active visual exploration of the remote scenario. In June 2008, within the framework of the experimental methodology, five healthy subjects performed pre-established navigation and visual exploration tasks for one week between two cities separated by 260 km. On the basis of the results, a technical evaluation of the device and its main functionalities is reported. The overall result is that all the subjects were able to successfully solve all the tasks reporting no failures, showing a high robustness of the system.
2009 IEEE International Conference on Robotics and Automation, ICRA 2009, Kobe, Japan, May 12-17, 2009; 01/2009