Comparison of Sensor Selection Mechanisms for an ERP-Based Brain-Computer Interface
R1–R5 denote the runs from each experimental session. In the intra-session scheme (left), the sensor selection (blue) is performed in the same run in which the system is trained (green), and the evaluation (red) is performed on the remaining runs from that session. In the inter-session scheme (right), the sensor constellations are transferred to a different session of the same subject. Note that run and session numbering were permuted during the experiment so that in each condition, each run was used for sensor selection and training.