Proyecto BRAINS
English  Castellano
BRAINS. Brain interaction system for disabled people

Project objectives

The project aims for four different objectives

Objective 1: Using virtual reality-based techniques in order to optimize training in BCI systems.

The first objective comes from a research carried out in the INTENTIO project, and focuses on the search of techniques that allow for an adequate and efficient training protocol that reduces the time required for a subject to obtain a certain degree of control on her EEG signals. Even though there are many parameters to consider to define such a training protocol, there is no doubt that the most important ones refer to a correct choice of the mental tasks to be carried out by the subjects, and the type of feedback to provide. It has been mentioned that most of the times those protocols are imposed in a random fashion. In them, subjects under test, with a great concentration effort, must perform the different mental tasks they are imposed and that, nevertheless, are not always the m ost efficient to control a BCI system. As an added difficulty, the type of feedback they are provided is usually based on simple representations, that keep no relationship with the mental task, leading inmany cases to a state of lack of concentration.

There is a need for an exhaustive research on which mental task can turn out to be more convenient, specially in the first stages of the training process, and how they can help subjects to produce EEG patterns associated to those mental task that ar e easier to discriminate. In that sense, we intend to make use of virtual reality-based techniques to create different virtual environments that provide a feedback more related to each mental task, and hence evaluate if subjects achieve and mantain a greater control of their electroencefalographic signal, as compared to the control obtained when they are subjected to a conventional training, based on a classic feedback.

In the research developed to achieve this first objective, special interest w ill be set on the evaluation of other parameters aside from the capacity of control that the subjects have on their EEG signals, and that could affect a number of psychological factors very related to the learning capacity of the subjects. In that sense, the research entails an important component of evaluation, making it indispensable the participation of a group of psychologists that guarantee a correct evaluation methodology.

Objective 2: Development of a BCI system for the virtual cont rol of a wheelchair.

The second objective we intend to achieve in this project is the development of a brain-computer interface that involve the subjects in a virtual environment that simulates the control of a wheelchair. Th scientific community has a huge interesr in a BCI system that enables people with great disabilities in their motor functions to control a wheelchair, thus increasing their quality of life, but they agree it is not possible to suject somebody to control such a device if not in a safe environment. With this application these patients would be given a very valuable tool to practise in environments that in real situations would entail a great danger. In that sense, virtual reality is a highly useful tool to achieve this end.

It must be stressed that one of the main handicaps to get to control a wheelchair via a BCI systems in the limitations of the systems themselves. A brain-computer interface is able to discriminate with a certain degree of success between 2 differe nt mental tasks, being the classification considerably worse when we try yo increase the number of mental tasks to discriminate. This makes the ouput commands of a BCI reduce to the basic functions of a switch, making it possible to select only between two options, and highly limiting the commands to control a wheelchair. In that sense, the application to develop must be able to provide enough commands to adequately control the device.

Objective 3: Optimizing the performance of a BCI syst em

It consists on the research of a number of estimulations and techniques to extract and classify the characteristics that, as a whole, define a BCI system that reaches a certain bandwidth or number of order that can be processed every second or minute.

The BCI system will be based on Selective Attention. Selective Attention is widely studied cognitive process in the field of psychology. It consists on paying attention to a target stimulus, ignoring the rest, when presented a number o f visual and auditive stimuli. Attention plays a modulating role on the EEG characteristic that the stimuli provocates, increasing the energy corresponding to the stimulus the subject is paying attention to and decreasing the energy of the others. This effect has been widely proven for visual stimuli that provocate SSVEP. By the time of this writing, it has not been totally proven for auditive stimuli that provocate a ASSR (Auditory Steady-State Response).

Selective attention is a natural-born ch aracteristic in every human being, so the training process is much easier than with other types of BCI

Objective 4: Development of a virtual desktop.

A BCI system will be developed, in which the subject will be immersed in a virtual reality environment where a desktop will be presnted. The desktop will consist on a virtual keyboard, with a high bandwidth, that enables the patient to write words much more quickly than with the existing virtual keyboards. The achievment of this ob jective is linked to the previous ones.

© Proyecto BRAINS, 2009    Icono de conformidad con el Nivel Doble-A, 
							de las Directrices de Accesibilidad para el 
							Contenido Web 1.0 del W3C-WAI ¡CSS Válido!