02832nas a2200253   4500008004100000022001400041245012700055210006900182260001200251490000600263520200400269653002302273653003802296653002902334653002302363653001702386653001702403100002502420700002102445700002402466700002102490700001902511856004802530       2012                        eng d  a1662-453X00aCommunication and control by listening: towards optimal design of a two-class auditory streaming brain-computer interface.0 aCommunication and control by listening towards optimal design of  c12/20120 v63 aMost brain-computer interface (BCI) systems require users to modulate brain signals in response to visual stimuli. Thus, they may not be useful to people with limited vision, such as those with severe paralysis. One important approach for overcoming this issue is auditory streaming, an approach whereby a BCI system is driven by shifts of attention between two simultaneously presented auditory stimulus streams. Motivated by the long-term goal of translating such a system into a reliable, simple yes-no interface for clinical usage, we aim to answer two main questions. First, we asked which of two previously published variants provides superior performance: a fixed-phase (FP) design in which the streams have equal period and opposite phase, or a drifting-phase (DP) design where the periods are unequal. We found FP to be superior to DP (p = 0.002): average performance levels were 80 and 72% correct, respectively. We were also able to show, in a pilot with one subject, that auditory streaming can support continuous control and neurofeedback applications: by shifting attention between ongoing left and right auditory streams, the subject was able to control the position of a paddle in a computer game. Second, we examined whether the system is dependent on eye movements, since it is known that eye movements and auditory attention may influence each other, and any dependence on the ability to move one’s eyes would be a barrier to translation to paralyzed users. We discovered that, despite instructions, some subjects did make eye movements that were indicative of the direction of attention. However, there was no correlation, across subjects, between the reliability of the eye movement signal and the reliability of the BCI system, indicating that our system was configured to work independently of eye movement. Together, these findings are an encouraging step forward toward BCIs that provide practical communication and control options for the most severely paralyzed users.
10aauditory attention10aauditory event-related potentials10abrain-computer interface10adichotic listening10aN1 potential10aP3 potential1 aHill, Jeremy, Jeremy1 aMoinuddin, Aisha1 aHäuser, Ann-Katrin1 aKienzle, Stephan1 aSchalk, Gerwin  uhttp://www.ncbi.nlm.nih.gov/pubmed/23267312