Initial results of a high-speed spatial auditory BCI
Martijn Schreuder, Michael Tangermann and Benjamin Blankertz
Int J Bioelectromagnetism
Most P300 BCI approaches use the visual modality for stimulation. For use with ALS patients this
might not be the preferable choice because of sight deterioration. Moreover, using a modality different
from the visual one minimizes interference with possible visual feedback. Therefore, a multi-class
brain-computer interface paradigm is proposed that uses spatially distributed, auditive cues. Ten
subjects participated in an offline oddball task with the spatial location of the stimuli being a
discriminating cue. Different inter-stimulus intervals of 1000 ms, 300 ms and 175 ms were tested. With
averaging over multiple classifier outputs, selection scores went over 90% for most conditions; two
subjects reached a 100% correct score. Corresponding information transfer rates were high, up to an
average optimal score of 20.99 bits/minute for the 175 ms condition (best subject 37.80 bits/minute).
We conclude that the proposed paradigm is successful for healthy subjects and shows promising results
that may lead to a fast BCI that solely relies on the auditory sense.