Feasibility of using time-domain parameters as online therapeutic BCI features

Feature extraction and selection is a major issue in brain computer interfaces. In an electroencephalogram based brain computer interface bandpower features are widely used. Time domain parameters (TDP) are other features which have not been extensively tested in online brain computer interfaces. In this study with eight naive subjects, it is shown that the time domain parameters (TDP) are suitable online features for a motor imagery based therapeutic brain computer interface. ERD/ERS maps were compared between trials selected as motor imagery-active and those rejected when using TDP as features. The ERD/ERS maps of the trials selected with the TDP method show ERD mainly in the 8-12 Hz frequency band on the hemisphere corresponding to the hand the subjects were imagining to move. There were significantly stronger ERDs in the trials that were selected than in those rejected.