Evaluation of audiovisual evoked potentials for multiple commands in BCI

The amplitude of steady-state evoked potentials are modulated by the attention-level payed to the stimuli. In this manuscript, the effects of the multisensory stimulation (auditory and visual) are evaluated for generation of commands in a brain-computer interface experiment. Electroencephalographic signals were acquired from disposable electrodes on non-hair positions along with occipital electrodes. Three visual stimuli were presented at 37, 38 and 39 Hz and two amplitude modulation auditory stimuli at 38 and 39 Hz were used as well. The carrier signal was 1000 Hz. Then, these stimuli were combined into four different modes. Six volunteers participated on the experiments. Multisensory stimulation allows to obtain an increased performance of 15% on the detection of evoked potentials.