A hybrid BCI for neurofeedback-based attention training: design and preliminary evaluation

Neurofeedback therapies based on brain-computer interfaces (BCI) can be used for the rehabilitation of attention deficit hyperactivity disorder (ADHD), as an alternative to conventional treatments. In this paper the design, implementation and preliminary evaluation of Attenti-ON, a hybrid BCI for ADHD rehabilitation, is presented. Attenti-ON uses a Serious Game commanded by the level of attention estimated by the theta/beta ratio of the electroencephalogram as a neurofeedback and also incorporates a manual activity that focuses attention on the required cognitive task., Attenti-ON consists of an user interface and four modules: the first one acquires the electroencephalography signals from prefrontal electrodes, located at Fp1 and Fp2, and conditions them. The second module procceses the signals and generates a valid command for the third module which consists in the Serious Game, developed in Unity. In this module the speed of an animated avatar is modified by the level of attention. The last module is the manual control consisting of a keyboard or joystick. Two evaluations of Attenti-ON were conducted. The first one was to assess the systems operation by using a signals database. In the second one, the BCIs closed loop-performance on a healthy volunteer was evaluated and aimed at verifying that the speed of the avatar varied according to the level of attention of the volunteer, which was modified by simulated interference situations. These preliminary results suggest that Attenti-ON could be transfered to the clinical setting for its evaluation for the treatment of ADHD.