ABSTRACT
Actually, very little objective discussion has been carried out in the literature about the general usability of the brain–computer interfaces (BCIs), such as the comfort necessary to wear the EEG acquisition system for long term, their efficiency, and possible health problems provoked by their use. With respect to the EEG signal acquisition using electrodes with gel (considered the gold standard, and for this reason, it is the technique applied in clinics), the preparation time is a laborious process that begins with the localization of sites for the electrode montage. Recently, EEG dry electrodes have arisen in the market, which makes unnecessary the use of gel, paste, or saline, however, in a very expensive cost: a cap with 16 dry electrodes and accessories for EEG acquisition can cost some thousands of US dollars. BCIs based on Steady-State Visual Evoked Potential, depending on their frequency range, can cause epileptic seizures, migraine headaches, and visual fatigue.
