... featuressomewhat unnatural control methods (hand, foot, and tongue motor imagery), as well as variable accuracy and high computational demand. Thus, self-pacing is not theonly obstacle to naturalistic ... bandpower on C3 for the referenced signal.To determine the optimum spatial location and frequencyband for discrimination, we conducted a feature analysis by calculating Bhattacharyya distances ... valuemay be estimated by assuming that intended yes and noanswers are equally likely, and that all intended moves areequally likely. Under these assumptions, the average clas-sification accuracy...