Spatial location and sound timbre as informative cues in auditory BCI/BMI - Electrodes position optimization for brain evoked potential enhancement

The paper introduces a novel auditory BCI/BMI paradigm based on combined sound timbre and horizontal plane spatial locations as informative cues. The presented concept is based on responses to eight-directional audio stimuli with various tonal and environmental sound stimuli. The approach is based on a monitoring of brain electrical activity by means of the electroencephalogram (EEG). The previously developed by the authors spatial auditory stimulus is extended to varying in timbre sound stimuli which feature helps the subjects to attend to the targets. The main achievement discussed in the paper is an offline BCI analysis based on an optimization of electrode locations on the scalp and evoked response latency for further classification results improvement. The so developed new BCI paradigm is more user-friendly and it leads to better results comparing to previously utilized simple tonal or steady-state stimuli.