Haufe, S.S.HaufeTomioka, R.R.TomiokaDickhaus, T.T.DickhausSannelli, C.C.SannelliBlankertz, B.B.BlankertzNolte, G.G.NolteMüller, K.-R.K.-R.Müller2022-03-112022-03-112010https://publica.fraunhofer.de/handle/publica/36954010.1109/IEMBS.2010.56261772-s2.0-78650820331We localize the sources of class-dependent eventrelated desynchronisation (ERD) of the mu-rhythm related to different types of motor imagery in Brain-Computer Interfacing (BCI) sessions. Our approach is based on localization of singletrial Fourier coefficients using sparse basis field expansions (SFLEX). The analysis reveals focal sources in the sensorimotor cortices, a finding which can be regarded as a proof for the expected neurophysiological origin of the BCI control signal. As a technical contribution, we extend S-FLEX to the multiple measurement case in a way that the activity of different frequency bins within the mu-band is coherently localized.en004conference paper